--- Site: KABQ --- KABQ - Reference: ['valley /as indicated by modis and visible satellite imagery/ will '] 569 FXUS65 KABQ 132145 AFDABQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 245 PM MST FRI JAN 13 2012 .DISCUSSION... MAIN CONCERNS THIS FORECAST PACKAGE ARE TEMPS AND THE PAIR OF SYSTEMS SCOOTING ACROSS NM SUNDAY NIGHT THRU MONDAY NIGHT. LIGHT WINDS AND CLEAR SKIES SHOULD RESULT IN OVERNIGHT TEMPERATURES BEING VERY SIMILAR TO LAST NIGHTS READINGS. TODAYS HIGH TEMPERATURES ARE HIGHER THAN PREVIOUSLY EXPECTED ACROSS THE PLAINS...THUS...WITH CONTINUED DOWNSLOPING DUE TO LEE SIDE TROUGHING...HAVE RAISED TEMPERATURES A FEW DEGREES ACROSS THE EAST FOR TOMORROW. WESTERN AREAS SHOULD BE WARMER THAN TODAY AS WELL...THANKS TO SHORTWAVE RIDGING. BY TOMORROW NIGHT...KICKER SYSTEM WILL HELP EJECT THE CLOSED LOW OVER THE PACIFIC EASTWARD. AS IT MOVES EAST...IT WILL WEAKEN AND OPEN INTO A WAVE. AS IT APPROACHES THE STATE ON SUNDAY...THE SURFACE LEE TROUGH WILL STRENGTHEN AS WILL THE GRADIENT ALOFT. THUS...TEMPS SHOULD CONTINUE TO RISE...ESPECIALLY ACROSS THE EAST. THE WAVE WILL MOVE ACROSS THE STATE SUNDAY NIGHT THROUGH EARLY MONDAY...SPREADING PRECIPITATION ALONG AND WEST OF THE CENTRAL MOUNTAIN CHAIN. WEST SLOPES SHOULD BENEFIT MOST FROM THIS SYSTEM...THOUGH ATTM...ONLY A FEW INCHES OF SNOW IS EXPECTED. KICKER SYSTEM MOVES ACROSS COLORADO MONDAY AFTN/NIGHT. THIS WILL CONTINUE PRECIPITATION ACROSS THE NORTHWEST MOUNTAINS...ESPECIALLY WEST SLOPES...THRU LATE MONDAY NIGHT. THE COMBINATION OF THE TWO SYSTEMS MAY RESULT IN ENOUGH SNOW TO WARRANT WINTER WEATHER ADVISORIES ACROSS THE NORTHWEST MTNS AND ADJACENT HIGHLANDS. HOWEVER...THERE IS STILL MUCH DISAGREEMENT AMONG THE MODELS WITH REGARDS TO HOW MUCH QPF WILL BE ASSOCIATED WITH EACH SYSTEM. PERHAPS THE BIGGER STORY WILL BE THE WIND ON MONDAY. BOTH THE NAM AND THE GFS ARE BOASTING 700 MB WIND SPEEDS OF 50 TO 60KT...LAPSE RATES ON THE ORDER OF 6 TO 7 DEG C/KM...AND A STRONG SURFACE LOW OVER SOUTHEAST COLORADO. THIS ALL POINTS TO A WINDY DAY ACROSS THE EASTERN PLAINS...ESPECIALLY ALONG THE RIDGETOPS OF THE CENTRAL MTN CHAIN...AS WELL AS ALONG THE I-40 CORRIDOR. THESE STRONG WINDS MAY START QUITE EARLY MONDAY MORNING...ESPECIALLY ALONG RIDGETOPS. AS THE EVENT DRAWS CLOSER...WILL LIKELY NEED TO ISSUE WIND ADVISORIES. SYSTEM NUMBER TWO MOVES OUT BY TUESDAY MORNING AND AN ASSOCIATED BACK DOOR FRONT WILL MOVE DOWN THE PLAINS...COOLING TUESDAYS HIGH TEMPERATURES 10 TO 20 DEGREES FROM MONDAYS READINGS. QUIETER NORTHWEST FLOW WILL PREVAIL THEREAFTER...WITH GRADUALLY WARMING TEMPERATURES. 34 && .AVIATION... VFR CONDITIONS EXPECTED ALL AREAS OVER THE NEXT 24 HOURS. NEXT AVIATION DISCUSSION SCHEDULED FOR 10Z. 50 && .FIRE WEATHER... VENTILATION WILL REMAIN A CONCERN THROUGH SATURDAY AS HIGH PRESSURE REMAINS IN CONTROL. ALTHOUGH TEMPERATURES WILL WARM A LITTLE BIT MORE AND MODELS SHOW A VERY WEAK SURFACE TROUGH ACROSS THE NORTHEAST PLAINS. MID LEVEL DRY SLOT REMAINS A CONCERN AND HAS DRIVEN SURFACE DEWPOINTS WELL BELOW MODEL GUIDANCE AGAIN TODAY. EXPECT ANOTHER ROUND A POOR TO MODERATE RECOVERIES ACROSS MOST MID SLOPE AND UPPER RIDGE AREAS AGAIN TONIGHT. THE MID LEVEL DRY SLOT WILL REMAIN IN CONTROL OVER THE STATE INTO SATURDAY. QUITE A FEW AREAS WILL SEE HUMIDITIES IN THE TEENS ALTHOUGH THE SNOW FIELD AREAS NEAR GRANTS AND WITHIN THE ESTANCIA VALLEY /AS INDICATED BY MODIS AND VISIBLE SATELLITE IMAGERY/ WILL REMAIN A LITTLE MORE MOIST. WEATHER MODELS REMAIN CONSISTENT WITH INCREASING THE FLOW ALOFT AND AT THE SURFACE SUNDAY AND CONTINUING THAT TREND IN MONDAY. MADE VERY FEW TWEAKS TO THE SUNDAY AFTERNOON WIND GRIDS. THE STRONGEST BREEZES SHOULD BE FOUND ACROSS THE EASTERN PLAINS AND HIGHER RIDGES OF THE CENTRAL MOUNTAINS. BASED ON THE MIN RH FORECAST LOCALIZED CRITICAL FIRE WEATHER GROWTH CONDITIONS WILL BE POSSIBLE BETWEEN SANTA ROSA AND THE TEXAS STATE LINE FOR A COUPLE OF HOURS SUNDAY AFTERNOON. HAINES INDEX FORECAST IS DEPICTED TO BE A 5 AND MAX TEMPERATURES ACROSS THAT AREA SHOULD RANGE BETWEEN 10 TO 15 DEGREES ABOVE NORMAL SO THERE IS SOME POTENTIAL THERE. ALTHOUGH SNOW IN DECEMBER HAS HELPED TO FLATTEN SOME OF THE GRASSIER AREAS LEFT OVER FROM THE SHORTENED GROWING SEASON IN 2011. VENTILATION WOULD CERTAINLY IMPROVE ON SUNDAY AND MODELS HAVE INCREASED THE LAPSE RATES FOR THAT DAY AS COMPARED TO YESTERDAY/S RUN. MONDAY APPEARS TO BE THE BIG WIND DAY AS MODELS FAVOR A 50 TO 60 MPH 10000 FOOT AIRFLOW OVER CENTRAL AND EASTERN AREAS DURING THE DAY. THIS WILL CERTAINLY INCREASE VENTILATION AREAWIDE INTO THE GOOD TO EXCELLENT CATEGORY. MODELS ARE ALSO CONSISTENT WITH RAPIDLY PUSHING OUT THE MID AND HIGH LEVEL CLOUDS INITIALLY STARTING THE DAY OVER SOUTHERN AND EASTERN AREAS. NORTHWEST/NORTH CENTRAL AREAS WILL STILL BE TANGLING WITH CLOUDS THANKS TO THE MAIN TROUGH PASSAGE UP THAT WAY. STEEPER LAPSE RATES AND 5 TO 10 DEGREE ABOVE NORMAL MAX TEMPS ACROSS THE EASTERN PLAINS WOULD MAKE FOR A NEAR CRITICAL DAY DURING THE AFTERNOON PERIOD ONCE THE CIRRUS SHOVES OFF TO THE EAST. DEWPOINT AND SUBSEQUENT RH FORECASTING WILL BE TRICKY FOR THE EASTERN PLAINS DURING THIS PERIOD. CURRENTLY HAVE MIN RH VALUES ABOVE 20 PCT BUT CANT RULE OUT SOME UPPER TEENS WHICH WOULD MAKE CONDITIONS A BIT MORE CRITICAL THERE. DID RAISE WIND SPEED VALUES ACROSS THE EASTERN PLAINS. WILL CONTINUE TO MONITOR THAT TREND FOR MONDAY. PRECIPITATION CHANCES AGAIN...LOOK TO FAVOR THE NORTHWEST MOUNTAINS SUNDAY NIGHT THROUGH MONDAY NIGHT BASED ON BLOCKING FLOW AND LAPSE RATE CONSIDERATIONS /AKA UPSLOPE/. MODELS ARE NOW DEPICTING A DOUBLE PERIOD FOR THE PRECIPITATION...INITIALLY STARTING OUT WITH THE CALIFORNIA COAST WAVE SUNDAY NIGHT AND THEN TRANSITIONING TO THE NORTHERN STREAM ENERGY OF THE MEAN JET STREAM OR TROUGH PASSAGE LATER MONDAY INTO MONDAY NIGHT. EITHER WAY...WETTING PRECIPITATION IN THE FORM OF SNOW IS ANTICIPATED FOR NORTHWEST AREAS...ESPECIALLY THE MOUNTAINS. LIGHTER SHOWERS WOULD BE FOUND ELSEWHERE ACROSS WESTERN AND CENTRAL AREAS. THE EASTERN PLAINS WOULD BE TOO SHADOWED WITH MAINLY VIRGA OR HIGH BASED PASSING SHOWERS SUNDAY NIGHT INTO MONDAY MORNING. MEDIUM RANGE MODELS REMAIN CONSISTENT WITH DRYING OUT THE FLOW FOR TUESDAY AND WEDNESDAY. FLOW ALOFT IS DEPICTED TO BE MODERATELY STRONG SO THIS WOULD FAVOR VENTILATION A LITTLE BETTER THAN WHAT WE HAVE BEEN SEEING. CURRENT GRIDDED FORECAST SHOWS QUITE A FEW FAIR/S ACROSS THE HIGHER TERRAIN AND SOME GOOD TO VERY GOOD ACROSS THE EASTERN PLAINS WHERE SURFACE WINDS WOULD BE A BIT STRONGER. TEMPERATURES WOULD START OUT COOLER THAN NORMAL TUESDAY BUT WARM TO NEAR AND A FEW DEGREES ABOVE NORMAL ON WEDNESDAY. A SIMILAR FLOW PATTERN...ZONAL TO SLIGHTLY NORTHWESTERLY...MENTIONED ABOVE IS DEPICTED FOR THURSDAY AND FRIDAY OF NEXT WEEK. ONCE AGAIN...SUSPECT THE FLOW WOULD LARGELY BE DRY WITH JUST A FEW WEAK WAVES PROVIDING SOME LIGHT SHOWERS ACROSS THE FAR NORTHERN MOUNTAINS. VENTILATION WOULD ONCE AGAIN BE POOR WITHIN THE VALLEYS BUT A TAD BETTER ACROSS THE HIGHER RIDGES AND PORTIONS OF THE EASTERN PLAINS. TEMPERATURES DURING THIS PERIOD WOULD GRADUALLY WARM AND ALLOW FOR SOME ABOVE NORMAL READINGS...ESPECIALLY EASTERN PLAINS. THE UPCOMING PATTERN AND PATTERN WE HAVE SEEN SINCE LATE DECEMBER IS LOOKING VERY SIMILAR TO THE PATTERN WE OBSERVED IN JANUARY OF 2011. 50 && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 8 44 13 49 / 0 0 0 0 DULCE........................... -1 45 5 47 / 0 0 0 5 CUBA............................ 8 48 13 48 / 0 0 0 0 GALLUP.......................... 0 50 7 50 / 0 0 0 5 EL MORRO........................ 10 48 14 47 / 0 0 0 5 GRANTS.......................... -6 34 -1 34 / 0 0 0 5 QUEMADO......................... 13 50 17 51 / 0 0 0 5 GLENWOOD........................ 20 58 20 59 / 0 0 0 0 CHAMA........................... 1 42 9 42 / 0 0 0 0 LOS ALAMOS...................... 18 45 22 46 / 0 0 0 0 PECOS........................... 18 48 22 45 / 0 0 0 0 CERRO/QUESTA.................... -3 37 2 35 / 0 0 0 0 RED RIVER....................... 12 39 14 40 / 0 0 0 0 ANGEL FIRE...................... -3 39 4 42 / 0 0 0 0 TAOS............................ 2 44 7 43 / 0 0 0 0 MORA............................ 16 49 20 48 / 0 0 0 0 ESPANOLA........................ 14 50 18 51 / 0 0 0 0 SANTA FE........................ 16 47 21 46 / 0 0 0 0 SANTA FE AIRPORT................ 15 48 18 47 / 0 0 0 0 ALBUQUERQUE FOOTHILLS........... 21 47 24 50 / 0 0 0 0 ALBUQUERQUE HEIGHTS............. 22 48 25 52 / 0 0 0 0 ALBUQUERQUE VALLEY.............. 18 49 21 53 / 0 0 0 0 ALBUQUERQUE WEST MESA........... 19 48 21 52 / 0 0 0 0 LOS LUNAS....................... 13 49 18 54 / 0 0 0 0 RIO RANCHO...................... 18 48 21 50 / 0 0 0 0 SOCORRO......................... 21 51 23 56 / 0 0 0 0 SANDIA PARK/CEDAR CREST......... 14 45 20 51 / 0 0 0 0 TIJERAS......................... 16 45 20 51 / 0 0 0 0 MORIARTY/ESTANCIA............... 14 42 17 44 / 0 0 0 0 CLINES CORNERS.................. 13 41 20 43 / 0 0 0 0 GRAN QUIVIRA.................... 17 47 21 48 / 0 0 0 0 CARRIZOZO....................... 15 54 20 55 / 0 0 0 0 RUIDOSO......................... 21 54 25 54 / 0 0 0 0 CAPULIN......................... 14 49 20 50 / 0 0 0 0 RATON........................... 10 58 16 60 / 0 0 0 0 SPRINGER........................ 16 53 18 54 / 0 0 0 0 LAS VEGAS....................... 17 55 22 55 / 0 0 0 0 CLAYTON......................... 23 60 29 65 / 0 0 0 0 ROY............................. 21 54 24 58 / 0 0 0 0 CONCHAS......................... 23 59 27 63 / 0 0 0 0 SANTA ROSA...................... 21 58 26 60 / 0 0 0 0 TUCUMCARI....................... 19 61 26 65 / 0 0 0 0 CLOVIS.......................... 24 60 25 63 / 0 0 0 0 PORTALES........................ 22 61 25 64 / 0 0 0 0 FORT SUMNER..................... 19 63 24 67 / 0 0 0 0 ROSWELL......................... 19 59 21 66 / 0 0 0 0 PICACHO......................... 19 62 24 64 / 0 0 0 0 ELK............................. 21 56 26 57 / 0 0 0 0 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 34/50 ______________________________________________________________________ KABQ - Reference: ['but the modis airmass rgb/goes h20 imagery suggests there may be'] 972 FXUS65 KABQ 252047 AFDABQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 247 PM MDT SUN MAR 25 2012 .DISCUSSION... SOME MID-LEVEL MOISTENING WAS NOTED ON THE 12Z KEPZ AND MMCU SOUNDINGS THIS MORNING...THOUGH NOT VERY IMPRESSIVE OVERALL. REGARDLESS...SOME MID LEVEL MOISTURE IS MOVING NORTHWARD. HIGH BASED CU HAS DEVELOPED FROM KSRR NORTHWARD TO KCQC...WITH SOME ADDITIONAL DEVELOPMENT ALONG/EAST OF THE SANGRE DE CRISTOS. RADAR DATA INDICATES SOME PRECIP IS FALLING...BUT GIVEN VERY LOW SURFACE DEWPOINTS...ITS NOT LIKELY MAKING IT TO THE GROUND. ADDITIONALLY...THUS FAR...ITS NOT BEEN VIGOROUS ENOUGH FOR ANY LIGHTNING PRODUCTION EITHER. STRUGGLED WITH WHAT TO DO WITH POPS/WX FOR THE EVENING AND OVERNIGHT HOURS. NAM HAS REALLY BACKED OFF ON PRODUCING ANY QPF ALONG/EAST OF THE CENTRAL MTN CHAIN...GFS HAS AS WELL...THOUGH STILL PRODUCES SOME. OPTED TO KEEP 10-POPS/DRY T/GUSTY WIND MENTION FROM KCQC SOUTH...WHERE BETTER MID LEVEL MOISTURE EXISTS WITH LARGE INVERTED-V SOUNDINGS. REMOVED POPS NORTH OF THIS AREA THOUGH KEPT DRY T AND SPRINKLES MENTION FOR THE EVENING HOURS. AFTER SUNSET...SUSPECT THIS ACTIVITY WILL WANE SOME...THUS REMOVED POPS BUT AGAIN LEFT DRY T/SPRINKLES MENTION. NOT TERRIBLY CONVINCED THERE WILL BE THUNDER...HOWEVER. HIGH CLOUDS HAVE MODERATED TEMPS A BIT ACROSS THE WEST TODAY... HOWEVER...THE OTHER STORY FOR TODAY WILL BE THE RECORD HIGH TEMPERATURES ACROSS CENTRAL AND EASTERN PORTIONS OF THE AREA.. SEVERAL LOCATIONS HAVE ALREADY TIED OR BROKEN THEIR RECORD HIGHS FOR THE DATE...INCLUDING THE ABQ SUNPORT...SANTA FE...RATON...LAS VEGAS...CLAYTON...AND TUCUMCARI. AS SHORTWAVE GLANCES THE FOUR CORNERS AREA ON MONDAY...WINDS WILL PICK UP AND SCOUR OUT THE MOISTURE IN THE EAST THAT CONTINUES TO ADVECT INTO THE AREA TONIGHT. MAY SEE AN ISOLATED TSTM NEAR THE TEXAS BORDER BEFORE THE PSUEDO-DRYLINE PUSHES INTO TEXAS. OTHERWISE...MAIN STORY WILL BE THE WIND. WILL LIKELY NEED A FEW WIND ADVISORIES ACROSS THE NORTHEAST WHERE SFC GRADIENT IS THE STRONGEST. WEST-SOUTHWESTERLY FLOW ALOFT WILL CONTINUE THROUGH WEDNESDAY AND IT DOES NOT APPEAR THE GULF MOISTURE WILL SLOSH BACK INTO OUR SE ZONES UNTIL WEDNESDAY NIGHT. ANOTHER SHORTWAVE WILL CROSS THE STATE THURSDAY AND FRIDAY...THOUGH LOOKS TO BE MAINLY DRY AT THIS TIME. IT MAY SPARK A THUNDERSTORM OR TWO WHERE BETTER GULF MOISTURE RESIDES THURSDAY AFTN/EVE ALONG THE TEXAS BORDER. OTHERWISE... TUESDAY-FRIDAY WILL FEATURE CONTINUED ABOVE NORMAL TEMPERATURES FOR LATE MARCH. 34 && .AVIATION... SOUTH TO SOUTHWEST FLOW WILL BECOME MORE WESTERLY LATE TONIGHT AND MONDAY AS UPPER RIDGE AXIS SHIFTS INTO GREAT PLAINS AND UPPER LOW/TROUGH TRACK INTO GREAT BASIN/COLORADO. LOW LEVEL MOISTURE RETURN TO THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN AS WELL AS A WEAK MID LEVEL MOISTURE PLUME MAY SPARK ISOLD -TSRA G40KT. MVFR CIGS MAY DEVELOP OVER SOUTHEAST NEW MEXICO TONIGHT BUT MAY NOT REACH THE MAJORITY OF CHAVES OR ROOSEVELT COUNTIES. MOISTURE TO BE SWEPT EASTWARD MONDAY AS SOUTHWEST SURFACE WINDS STRENGTHEN. NEXT AVIATION DISCUSSION SCHEDULED FOR 09Z. && .FIRE WEATHER... UPPER RIDGE AXIS WILL CONTINUE TO SHIFT INTO THE GREAT PLAINS AS UPPER TROUGH/LOW TRACKS INTO THE GREAT BASIN/COLORADO TONIGHT/MONDAY. WIDESPREAD MIN RH VALUES OF LESS THAN 15 PERCENT THIS AFTERNOON WON/T RECOVER TONIGHT IN THE WEST AND CENTRAL...WHERE ONLY FAIR TO POOR RECOVERIES AREA EXPECTED. IN THE EAST CENTRAL/SOUTHEAST PLAINS RECOVERIES WILL BE BETTER AS AT LEAST ONE MODEL SUGGESTS LOW LEVEL MOISTURE COULD BACK TO NEAR THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN. AT THE SAME TIME...MODELS STILL INSISTING A WEAK PLUME OF MID LEVEL MOISTURE WILL ADVANCE NORTHWARD ALONG AND IMMEDIATELY EAST OF THE CENTRAL MOUNTAIN CHAIN. THIS IS NOT VERY OBVIOUS ON WATER VAPOR IMAGERY BUT THE MODIS AIRMASS RGB/GOES H20 IMAGERY SUGGESTS THERE MAY BE SOMETHING ORIGINATING FROM WHERE MODELS INDICATE THE SOURCE REGION IS LOCATED. MORNING MMCU SOUNDING DOES SHOW LAYER OF MID LEVEL MOISTURE BUT NOT VERY IMPRESSIVE. WITH A FEW BUILDUPS OVER THE SACRAMENTO MOUNTAINS AS OF THIS WRITING...POTENTIAL FOR DRY CONVECTION TO REMAIN IN FORECAST FOR THE REST OF THIS AFTERNOON/TONIGHT. MOISTURE IS SWEPT TO THE EAST ON MONDAY WITH SMALL CHANCES FOR CONVECTION ALONG THE TEXAS BORDER...DRY OTHERWISE...AND WINDY. HIGH TEMPERATURES REMAIN ABOVE AVERAGE ALTHOUGH THEY WILL BE 5 TO 10 DEGREES COOLER...WHICH SHOULD BOOST MIN RH VALUES A FEW PERCENT IN THE WEST. HAINES WILL STILL BE 5 TO 6 SOUTH OF INTERSTATE 40 AND OVER MOST OF THE PLAINS. CRITICAL CONDITIONS STILL LIKELY OVER THE CURRENT WARNED AREA MONDAY. WINDS SHOULD DIMINISH TUESDAY AND REMAIN BELOW AVERAGE FOR LATE MARCH THROUGH THE WORK WEEK. LOW LEVEL MOISTURE MAY MAKE SHORT APPEARANCES IN THE SOUTHEAST/EAST CENTRAL PLAINS BUT ELSEWHERE IT WILL BE DRY WITH MIN RH VALUES BELOW 15 PERCENT AND AT BEST FAIR OVERNIGHT RECOVERIES. ABOVE TO WELL ABOVE NORMAL TEMPERATURES ARE FORECAST THROUGH THURSDAY WITH GENERALLY GOOD OR BETTER VENTILATION ALTHOUGH A FEW POCKETS OF FAIR TO POOR ARE POSSIBLE NORTHWEST. FOR LATE IN THE WEEK...MODELS ARE AT ODDS WITH THE FRIDAY WEATHER PATTERN...AS WELL AS THE DEVELOPING LOW OVER THE GREAT BASIN...NO FOOLING. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 40 64 31 68 / 0 0 0 0 DULCE........................... 36 64 25 65 / 0 0 0 0 CUBA............................ 36 66 31 69 / 0 0 0 0 GALLUP.......................... 29 61 23 66 / 0 0 0 0 EL MORRO........................ 27 60 24 64 / 0 0 0 0 GRANTS.......................... 31 67 23 70 / 0 0 0 0 QUEMADO......................... 34 65 29 68 / 0 0 0 0 GLENWOOD........................ 27 69 27 73 / 0 0 0 0 CHAMA........................... 31 58 24 59 / 5 5 0 0 LOS ALAMOS...................... 46 67 40 67 / 0 0 0 0 PECOS........................... 43 66 36 66 / 5 0 0 0 CERRO/QUESTA.................... 38 66 28 67 / 5 0 0 0 RED RIVER....................... 36 56 27 56 / 5 5 0 0 ANGEL FIRE...................... 30 59 24 59 / 5 5 0 0 TAOS............................ 34 66 26 66 / 0 0 0 0 MORA............................ 43 66 33 67 / 5 5 0 0 ESPANOLA........................ 36 75 27 74 / 0 0 0 0 SANTA FE........................ 46 66 39 65 / 0 0 0 0 SANTA FE AIRPORT................ 41 70 34 69 / 0 0 0 0 ALBUQUERQUE FOOTHILLS........... 47 71 42 71 / 0 0 0 0 ALBUQUERQUE HEIGHTS............. 49 72 43 72 / 0 0 0 0 ALBUQUERQUE VALLEY.............. 45 73 38 74 / 0 0 0 0 ALBUQUERQUE WEST MESA........... 47 73 39 73 / 0 0 0 0 LOS LUNAS....................... 44 75 36 75 / 0 0 0 0 RIO RANCHO...................... 48 72 39 72 / 0 0 0 0 SOCORRO......................... 42 81 39 80 / 0 0 0 0 SANDIA PARK/CEDAR CREST......... 40 68 36 68 / 5 0 0 0 TIJERAS......................... 43 71 38 73 / 0 0 0 0 MORIARTY/ESTANCIA............... 42 70 35 69 / 5 0 0 0 CLINES CORNERS.................. 43 68 36 68 / 10 5 0 0 GRAN QUIVIRA.................... 42 71 38 72 / 5 0 0 0 CARRIZOZO....................... 38 73 36 75 / 0 0 0 0 RUIDOSO......................... 43 66 41 68 / 10 5 0 0 CAPULIN......................... 50 71 36 71 / 5 5 0 0 RATON........................... 42 77 33 76 / 5 5 0 0 SPRINGER........................ 47 77 37 75 / 5 5 0 0 LAS VEGAS....................... 43 70 37 70 / 5 5 0 0 CLAYTON......................... 50 79 44 77 / 5 5 0 0 ROY............................. 50 76 41 75 / 5 5 0 0 CONCHAS......................... 56 82 40 80 / 5 5 0 0 SANTA ROSA...................... 52 80 43 79 / 5 5 0 0 TUCUMCARI....................... 55 84 45 85 / 5 5 5 0 CLOVIS.......................... 50 80 43 82 / 5 10 5 0 PORTALES........................ 54 81 43 83 / 5 10 5 0 FORT SUMNER..................... 49 86 41 87 / 5 5 5 0 ROSWELL......................... 53 86 42 87 / 5 5 5 0 PICACHO......................... 50 81 44 83 / 5 5 0 0 ELK............................. 46 74 41 77 / 5 5 0 0 && .ABQ WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 11 AM TO 9 PM MDT MONDAY FOR THE FOLLOWING ZONES...NMZ103-104-107-108. RED FLAG WARNING UNTIL 6 PM MDT THIS EVENING FOR THE FOLLOWING ZONES...NMZ103. && $$ 34/99 ______________________________________________________________________ KABQ - Reference: ['500mb. experimental modis rgb airmass imagery from nasa sport this'] 776 FXUS65 KABQ 090918 AFDABQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 318 AM MDT THU AUG 9 2012 .DISCUSSION... THE SIGNIFICANT UPPER LEVEL DRY AIR INTRUSION THAT PUSHED SOUTH ACROSS THE E PLAINS WILL EXPAND SOUTHWEST AND ENVELOP NEARLY THE ENTIRE STATE TODAY. CIRA BLENDED PERCENT OF NORMAL PWAT IMAGERY INDICATES VALUES NEAR 75PCT OF NORMAL ACROSS A VAST AREA OF THE FRONT RANGE AND HIGH PLAINS. THE 00Z RAOB AT KAMA SHOWS EXTREMELY DRY CONDITIONS ABOVE 600MB WITH SIMILAR CONDITIONS AT KABQ ABOVE 500MB. EXPERIMENTAL MODIS RGB AIRMASS IMAGERY FROM NASA SPORT THIS MORNING SHOWS THIS VERY WELL. THE BULK OF 00Z MODEL GUIDANCE PICKS UP ON THIS FEATURE AS WELL AND WAS TEMPTED TO REMOVE JUST ABOUT ALL POPS FROM THE FORECAST TODAY...HOWEVER SOME MOISTURE REMAINS IN PLACE ALONG THE AZ BORDER AND THE NW MOUNTAINS. TEMPS WILL TREND UP A DEGREE OR TWO OVER WEDNESDAYS HIGHS STATEWIDE. THE CURRENT 597DM H5 HIGH OVER THE FOUR CORNERS WILL WEAKEN TO 594DM FRIDAY AND SAG SLIGHTLY SOUTH. THE UPPER DRY WEDGE WILL ROUND THE SOUTHERN PERIPHERY OF THE HIGH INTO AZ WHILE A WEAK VORTICITY MAX CURRENTLY OVER THE SALT LAKE AREA DIVES SE ACROSS COLORADO AND NE NM ON THE EAST SIDE OF THE RIDGE. THE NAM IS VERY AGGRESSIVE WITH PRECIP DEVELOPMENT WITH THIS FEATURE WHEREAS MOST OTHER GUIDANCE KEEPS THINGS ON THE DRIER SIDE. CONTINUED TREND FROM DAY SHIFT TO BACK OFF ON COVERAGE OF STORMS. AN UPPER TROUGH WILL SLIDE SE ACROSS THE NORTHERN PLAINS SATURDAY WEAKENING THE H5 RIDGE EVEN FURTHER TO 592DM. ANOTHER ROUND OF STORMS IS POSSIBLE IN NW FLOW OVER THE NE PLAINS SO FOCUS FOR GREATEST STORM COVERAGE REMAINS ACROSS THE NORTHEAST. SURFACE HIGH PRESSURE BUILDING SOUTH DOWN THE FRONT RANGE BEHIND THIS EXITING UPPER TROUGH WILL FORCE A FRONT SOUTH ACROSS THE PLAINS SUNDAY. THIS FRONT IS TRENDING MORE VIGOROUS OVER THE PAST COUPLE MODEL RUNS AND APPEARS TO BE WETTER THAN OUR LAST FRONT OVER THIS PAST WEEKEND. MEANWHILE...AN UPPER TROUGH AXIS BEGINS TAKING SHAPE OVER THE WEST COAST FORCING THE MID AND UPPER LEVEL RIDGE AXIS EAST TOWARD TX. THIS MAY POTENTIALLY FORCE A PERIOD OF BETTER STORM CHANCES SUNDAY THROUGH TUESDAY. MODELS ARE NOW SHOWING THE EASTERLY WAVE CURRENTLY OVER THE WESTERN CARIBBEAN MOVING WEST INTO SOUTHERN MEXICO THROUGH THE WEEKEND. THIS FEATURE THEN SLIDES NORTH AHEAD OF THE DEEPENING TROUGH ALONG THE WEST COAST. A DRY SLOT MAY MOVE THROUGH THE REGION AHEAD OF THIS WAVE WEDNESDAY FOLLOWED BY A POTENTIAL MONSOON BURST PATTERN TO FINISH OFF NEXT WEEK. GUYER && .FIRE WEATHER... WITH THE 500 MB HIGH PRESSURE SYSTEM CENTERED NEAR THE FOUR CORNERS...AND A PRONOUNCED REGION OF VARY DRY MID AND LOW LEVEL AIR SPREADING AROUND THE HIGH FROM EASTERN NM TO SOUTHWESTERN NM...THERE IS A MEAGER CHANCE OF WETTING PRECIPITATION TODAY. THE EXCEPTION WILL BE THE NORTHERN MOUNTAINS...WHERE SOME RECYCLED MOISTURE TRAPPED UNDER THE CENTER OF THE UPPER HIGH COULD RESULT IN A TENTH OR TWO OF AN INCH OF PRECIPITATION FROM A FEW THUNDERSTORMS. SIMILAR WEATHER IS EXPECTED FRIDAY...EXCEPT THE DRIEST MID LEVEL AIR WILL SHIFT OVER SE AZ BY THEN...AND THE POCKET OF RECYCLED MOISTURE COULD SPREAD TO INCLUDE NE NM WITH A MIX OF WET AND RELATIVELY DRY STORMS. MINIMUM HUMIDITIES WILL CRATER TO THE LOW TEENS AT MANY LOWER ELEVATION LOCATIONS TODAY AND FRIDAY. AN EXCEPTION WILL BE NOTED ACROSS THE NE PLAINS FRIDAY...WHERE READINGS SHOULD ONLY DROP TO THE UPPER TEENS. DUE TO THE PROXIMITY OF THE UPPER HIGH AND DRY AIR...TEMPERATURES THROUGH THE END OF THE WEEK WILL VARY FROM A FEW TO 10 DEGREES ABOVE NORMAL. OVER THE WEEKEND...THE UPPER RIDGE WILL ELONGATE ALONG AN AXIS FROM N CENTRAL AZ TO S CENTRAL NM. THE RESULTANT NW FLOW ALOFT OVER NE PARTS OF THE FORECAST AREA WILL OPEN THE DOOR FOR AN UPPER LEVEL TROUGH TO CROSS WITH AN UPTICK IN CONVECTION SATURDAY ACROSS NORTHERN AND EASTERN PARTS OF THE FORECAST AREA. AIDING THE CONVECTION WILL BE A MOISTER BACK DOOR COLD FRONT THAT MAY DROP INTO THE FAR NE PLAINS AS EARLY AS LATE SATURDAY AFTERNOON. THIS FRONT WONT MAKE MUCH PROGRESS UNTIL SUNDAY...WHEN AIDED BY OUTFLOWS FROM ANOTHER UPTICK IN THUNDERSTORM COVERAGE...IT WILL PUSH INTO THE RIO GRANDE VALLEY WITH A MODESTLY GUSTY EAST CANYON WIND DURING THE LATE AFTERNOON. LOW LEVEL CONVERGENCE ALONG THE FRONTAL BOUNDARY COULD KEEP THE EAST SLOPES OF THE WEST CENTRAL AND SOUTHWEST MOUNTAINS...AS WELL AS THE CONTINENTAL DIVIDE REGION...ACTIVE WITH WETTING THUNDERSTORMS WELL INTO SUNDAY NIGHT. AHEAD OF THE FRONTAL BOUNDARY ON SATURDAY...PARTS OF THE PLAINS SHOULD SEE HIGHS AROUND 12 DEGREES ABOVE NORMAL. READINGS WILL FALL A FEW DEGREES IN MOST LOCATIONS SUNDAY. IN ADDITION...MOISTURE WITH THE FRONT WILL BOOST MIN HUMIDITIES ABOVE CRITICAL THRESHOLDS IN MOST LOCATIONS BY SUNDAY AFTERNOON. GFS AND ECMWF NOW INDICATE THE UPPER HIGH PRESSURE CENTER WILL GRADUALLY SHIFT OVER SOUTHERN NM...THEN OVER TX...DURING THE FIRST HALF OF THE COMING WORK WEEK. AS MOISTURE RECYCLES MONDAY AND TUESDAY...CENTRAL AND WESTERN AREAS WILL BE FAVORED FOR SCATTERED TO ISOLATED AND SOMEWHAT WETTING STORMS. DURING THE MIDDLE TO LATTER HALF OF THE COMING WORK WEEK...MONSOON MOISTURE MAY WORK ITS WAY NORTHWARD INTO CENTRAL AND WESTERN PARTS OF THE STATE WITH AN EASTERLY WAVE TRACKING NORTHWARD AROUND THE PERIPHERY OF THE UPPER RIDGE. THIS WOULD CAUSE GREATER WETTING THUNDERSTORM COVERAGE AND COOLER TEMPERATURES. 44 && .AVIATION... 06Z TAF CYCLE RIDGE DOMINATING THE FOUR CORNERS REGION WITH SURFACE HIGH PRESSURE SITTING OVER CENTRAL COLORADO FOR THE NEXT 24 HOURS. WIDELY SCATTERED THUNDERSTORMS DEVELOPING FROM 19Z ONWARD THURSDAY AFTERNOON OVER WESTERN HALF OF NM...AND CARRIED IN TAFS AT FMN...GUP...AND SAF. EASTERLY WINDS THROUGH CENTRAL MOUNTAINS OVER THE RIO GRANDE VALLEY WILL REDUCE THUNDER COVERAGE NEAR ABQ THURSDAY AFTERNOON. OTHERWISE...VFR CIGS AND VIZ THROUGH THE NEXT 24 HOURS. SHY && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 97 68 96 65 / 5 10 10 10 DULCE........................... 90 54 89 53 / 10 10 20 20 CUBA............................ 91 56 91 56 / 5 5 10 10 GALLUP.......................... 92 59 89 60 / 10 10 5 5 EL MORRO........................ 83 55 81 57 / 20 20 10 5 GRANTS.......................... 90 56 90 59 / 5 5 5 5 QUEMADO......................... 91 55 90 56 / 20 20 10 5 GLENWOOD........................ 92 56 90 56 / 10 10 0 0 CHAMA........................... 84 52 83 51 / 30 30 30 30 LOS ALAMOS...................... 87 60 87 59 / 5 5 10 10 PECOS........................... 84 60 82 60 / 5 5 10 20 CERRO/QUESTA.................... 83 55 81 53 / 20 20 20 30 RED RIVER....................... 76 50 76 50 / 20 20 30 30 ANGEL FIRE...................... 80 50 78 50 / 20 20 30 30 TAOS............................ 88 55 85 54 / 10 10 20 20 MORA............................ 81 57 79 57 / 10 10 10 20 ESPANOLA........................ 94 59 93 59 / 5 5 10 10 SANTA FE........................ 88 61 87 61 / 5 5 10 10 SANTA FE AIRPORT................ 94 63 91 63 / 5 5 10 10 ALBUQUERQUE FOOTHILLS........... 93 65 92 66 / 0 5 5 5 ALBUQUERQUE HEIGHTS............. 95 67 94 67 / 0 5 0 5 ALBUQUERQUE VALLEY.............. 97 63 97 64 / 0 5 0 5 ALBUQUERQUE WEST MESA........... 97 65 97 66 / 0 5 0 5 LOS LUNAS....................... 95 63 94 64 / 0 5 0 5 RIO RANCHO...................... 98 65 96 66 / 0 5 5 5 SOCORRO......................... 99 65 99 67 / 0 5 0 5 SANDIA PARK/CEDAR CREST......... 90 60 90 60 / 5 5 5 10 TIJERAS......................... 93 60 93 60 / 5 5 5 5 MORIARTY/ESTANCIA............... 88 58 86 58 / 0 5 5 10 CLINES CORNERS.................. 89 60 88 60 / 5 5 5 10 GRAN QUIVIRA.................... 92 60 91 62 / 0 5 5 5 CARRIZOZO....................... 92 64 92 64 / 0 5 5 5 RUIDOSO......................... 83 57 83 58 / 5 5 10 10 CAPULIN......................... 89 58 88 60 / 10 10 20 20 RATON........................... 98 62 96 63 / 10 10 20 20 SPRINGER........................ 95 63 93 64 / 5 10 10 20 LAS VEGAS....................... 90 59 88 59 / 5 10 10 20 CLAYTON......................... 94 63 94 68 / 0 5 10 20 ROY............................. 92 64 91 66 / 0 10 10 20 CONCHAS......................... 98 69 97 71 / 0 0 5 10 SANTA ROSA...................... 99 68 98 69 / 0 0 0 10 TUCUMCARI....................... 100 71 98 72 / 0 0 5 10 CLOVIS.......................... 97 66 95 67 / 0 0 0 5 PORTALES........................ 98 66 96 68 / 0 0 0 5 FORT SUMNER..................... 98 71 97 71 / 0 0 0 5 ROSWELL......................... 99 72 98 70 / 0 0 0 5 PICACHO......................... 94 62 94 63 / 0 0 0 5 ELK............................. 88 58 88 59 / 0 0 5 5 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ GUYER/44/SHY ______________________________________________________________________ KABQ - Reference: ['700mb per 00z nam bufkit at ktcc and klvs. latest modis night-time'] 957 FXUS65 KABQ 120930 AFDABQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 330 AM MDT SUN AUG 12 2012 .DISCUSSION... AT 09Z THE BACK DOOR FRONTAL BOUNDARY WAS DRAPED FROM NEAR CLINES CORNERS EAST TO SOUTH OF TUCUMCARI. THERE IS SOME DECENT MOMENTUM BEHIND THE FRONT AS IT PUSHES SOUTH NEAR 20 KTS. SFC DEWPOINTS ARE RISING ABOUT 5F BEHIND THE FRONT. THE FRONT EXTENDS UP TO ABOUT 700MB PER 00Z NAM BUFKIT AT KTCC AND KLVS. LATEST MODIS NIGHT-TIME MICROPHYSICS IMAGERY SHOWS THE THETA-E RIDGE AXIS LINING UP WITH THE 00Z MODEL GUIDANCE FROM WEST TO EAST ACROSS THE NORTHERN HALF OF NM. THE FRONTAL BOUNDARY WILL CONTINUE PUSHING SOUTH AND WEST THRU THIS AFTERNOON AND LINE UP WELL WITH THE MID LEVEL MOIST INSTABILITY AXIS TO PRODUCE SCT TO NMRS SHOWERS AND STORMS OVER CENTRAL NM. RAISED POPS EVEN FURTHER FOR THE EAST SLOPES. TEMPS WILL ALSO BE MUCH COOLER AFTER SATURDAYS RECORD HIGHS ACROSS THE NE AND E CENTRAL PLAINS. THE BIG CHALLENGE WILL BE TONIGHT THRU TUESDAY WITH PLACEMENT OF HIGHEST POPS AND QPF. THE GFS DEPICTS LARGE AREAS OF QPF ALONG THE CENTRAL MT CHAIN MOVING SOUTH EACH EVENING WHERE OTHER MODELS ARE LESS BULLISH WITH AMOUNTS. HPC 12HR QPF LINES UP WELL WITH GFS SO HAVE RAISED POPS ANOTHER FEW POINTS FOR AREAS IN VCNTY OF CENTRAL MT CHAIN THRU TUESDAY. MAX TEMPS WILL TREND DOWN 5 TO 10F AREAWIDE WITH DEEPER MOISTURE AND CLOUD COVER. AT THIS POINT IT IS HARD TO PIN DOWN ANY SPECIFIC AREA THAT WOULD RECEIVE HEAVY RAINFALL AND ELEVATED FLASH FLOOD THREAT...SO WILL LEAVE OUT HEAVY WORDING FROM ZONES FOR NOW. CONFIDENCE ON THE WEATHER PATTERN WEDNESDAY THRU THE WEEKEND IS BEGINNING TO CREEP INTO THE MODERATE CATEGORY AS MODELS ARE GETTING A BETTER HANDLE ON THE TROUGH PASSAGE OVER THE NORTHERN PLAINS ON THURSDAY. THE H5 RIDGE WILL HAVE WEAKENED TO ABOUT 588DM AND SHIFTED SW INTO SW NM/SE AZ BY WEDNESDAY. RECYCLE MODE WILL TAKE OVER IN THIS PATTERN WITH NW FLOW OVER THE STATE. GUIDANCE SHOWS ANOTHER DECENT BACK DOOR FRONT PLOWING SOUTH INTO THE E PLAINS THURSDAY AS THE UPPER TROUGH EXITS INTO THE GREAT LAKES. THIS WILL BECOME ANOTHER FOCUS FOR INCREASED SHOWER AND STORM COVERAGE. THE BIG QUESTION IS STILL WHERE THE FRONTAL BOUNDARY WILL END UP OVER NM AS A DEEP TROPICAL WAVE ATTEMPTS TO SLIDE NORTH ACROSS MEXICO. GUYER && .FIRE WEATHER... BACK DOOR COLD FRONT CURRENTLY DROPPING SOUTH ACROSS THE EASTERN PLAINS...INCREASING HUMIDITIES SOMEWHAT EARLY THIS MORN AND COOLING TEMPS A FEW DEGREES ACROSS NE AND PORTIONS OF E CENTRAL NM. AFTN HIGH TEMPS THOUGH STILL EXPECTED TO BE UP TO 8 DEGREES ABOVE NORMAL BEHIND THE FRONT...ESPECIALLY E CENTRAL NM WHERE MAXIMUMS STILL LIKELY TO BE PRETTY CLOSE TO 100 DEGREES. WITH FRONT COZIED UP TO THE CENTRAL MTN CHAIN THIS AFTN...SHOWER AND THUNDERSTORM COVERAGE...AND WETTING RAIN POTENTIAL...WILL INCREASE FROM THERE EAST THIS AFTN AND EVE. FRONT WILL MOVE WEST THROUGH THE GAPS OF THE CENTRAL MOUNTAIN CHAIN TOWARD THE ARIZONA BORDER TONIGHT. LOW LEVEL MOISTURE REPLENISHMENT SHOULD RESULT IN QUITE A BIT MORE THUNDERSTORM COVERAGE ON MON COMPARED TO RECENT DAYS FOR MOST OF N AND CENTRAL NM AND WITH LARGER WETTING RAIN FOOTPRINTS. MOST CERTAINLY BETTER NIGHTTIME RH RECOVERIES ACROSS NEARLY ALL OF FCST AREA TONIGHT AND MORE SO MON NIGHT. RECYCLING OF MOISTURE IN THE FORM OF ISOLATED TO SCATTERED STORMS SHOULD DEVELOP TUE WITH THAT TREND CONTINUING THROUGH WED...THOUGH COVERAGE WILL DIMINISH SOMEWHAT WED. EVEN STRONGER BACK DOOR COLD FRONT MARCHES INTO NE NM ON THURSDAY INTO FRIDAY. THIS ONE MAY BE STRONGER THAN THE CURRENT E NM FRONT. ANOTHER MOISTURE INTRUSION BEHIND THIS FRONT SHOULD KICK UP THE THUNDERSTORM COVERAGE ONCE AGAIN AND COOLING BEHIND THE FRONT SHOULD RESULT IN AT LEAST 5 TO 15 DEGREES OF FURTHER COOLING...IF NOT MORE. 43 && .AVIATION... 06Z TAF CYCLE VFR CONDITIONS ARE FORECAST TO PERSIST THROUGH THE TAF PERIOD. BRIEF MVFR CONDITIONS ARE POSSIBLE IN SCATTERED SHOWERS AND THUNDERSTORMS SUNDAY AFTERNOON AND EVENING. A WEAK FRONT IS FORECAST TO PUSH SOUTH ACROSS THE EASTERN PLAINS OVERNIGHT THROUGH SUNDAY MORNING. THE FRONT WILL RESULT IN A ESE LOW LEVEL FLOW LATER SUNDAY AT BOTH KABQ AND KSAF...WITH AN EAST GAP WIND FORECAST AT KABQ SUNDAY EVENING. ALTHOUGH AWW CRITERIA WIND GUSTS ARE NOT ANTICIPATED SUNDAY EVENING AT KABQ...GUSTS NEAR 30KTS ARE LIKELY. 11 && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 96 65 93 64 / 10 30 20 30 DULCE........................... 89 52 87 52 / 20 40 40 30 CUBA............................ 94 53 88 53 / 20 60 50 40 GALLUP.......................... 92 58 88 58 / 20 30 20 30 EL MORRO........................ 86 53 80 54 / 30 30 50 40 GRANTS.......................... 91 54 85 53 / 30 30 50 40 QUEMADO......................... 90 56 91 54 / 30 30 30 30 GLENWOOD........................ 95 58 92 57 / 10 20 20 20 CHAMA........................... 82 52 78 52 / 40 50 60 40 LOS ALAMOS...................... 86 59 83 57 / 30 60 60 40 PECOS........................... 80 58 78 58 / 60 60 50 40 CERRO/QUESTA.................... 76 54 75 51 / 50 50 50 40 RED RIVER....................... 72 49 68 49 / 60 60 60 50 ANGEL FIRE...................... 74 47 71 47 / 60 60 60 50 TAOS............................ 86 53 83 53 / 30 50 50 40 MORA............................ 76 55 73 56 / 60 50 60 40 ESPANOLA........................ 92 59 88 58 / 10 40 40 40 SANTA FE........................ 88 58 83 57 / 30 50 40 40 SANTA FE AIRPORT................ 92 61 85 60 / 30 50 40 40 ALBUQUERQUE FOOTHILLS........... 92 63 89 62 / 10 50 40 40 ALBUQUERQUE HEIGHTS............. 95 67 91 65 / 5 40 30 40 ALBUQUERQUE VALLEY.............. 97 65 92 62 / 5 40 30 40 ALBUQUERQUE WEST MESA........... 96 65 92 65 / 5 50 30 40 LOS LUNAS....................... 95 65 91 64 / 5 40 30 40 RIO RANCHO...................... 95 65 91 64 / 5 50 40 40 SOCORRO......................... 98 65 96 63 / 5 30 40 30 SANDIA PARK/CEDAR CREST......... 89 56 86 58 / 50 60 50 40 TIJERAS......................... 92 59 89 58 / 30 50 40 40 MORIARTY/ESTANCIA............... 89 59 84 59 / 50 60 50 40 CLINES CORNERS.................. 87 57 82 58 / 60 60 60 40 GRAN QUIVIRA.................... 91 59 86 59 / 50 50 50 40 CARRIZOZO....................... 95 63 90 63 / 30 40 40 30 RUIDOSO......................... 86 57 80 58 / 50 40 60 30 CAPULIN......................... 82 56 83 56 / 30 20 40 40 RATON........................... 88 58 90 60 / 40 30 30 40 SPRINGER........................ 87 61 86 62 / 40 30 30 40 LAS VEGAS....................... 83 57 82 58 / 60 50 60 40 CLAYTON......................... 90 62 89 64 / 20 20 20 30 ROY............................. 85 65 87 65 / 20 20 30 30 CONCHAS......................... 93 69 92 70 / 20 30 20 30 SANTA ROSA...................... 96 67 94 68 / 20 40 20 30 TUCUMCARI....................... 98 70 96 72 / 20 20 20 20 CLOVIS.......................... 96 67 92 69 / 20 20 20 20 PORTALES........................ 98 68 94 69 / 20 20 20 20 FORT SUMNER..................... 97 69 93 71 / 20 40 20 20 ROSWELL......................... 101 71 96 71 / 20 30 20 20 PICACHO......................... 96 61 90 61 / 20 40 30 20 ELK............................. 92 58 85 58 / 40 40 30 20 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ GUYER/43/11 ______________________________________________________________________ KABQ - Reference: ['the rio grande valley westward. modis rgb imagery and obs verify'] 050 FXUS65 KABQ 271148 AFDABQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 548 AM MDT THU SEP 27 2012 .AVIATION... 12Z TAF CYCLE ACTIVE DAY AGAIN TODAY WITH LOCALLY STRONG SHRA/TSRA ALONG AND EAST OF THE CENTRAL MT CHAIN AND MAINLY DRY GUSTY -SHRA/TSRA FROM THE RIO GRANDE VALLEY WESTWARD. MODIS RGB IMAGERY AND OBS VERIFY SOME LOW CLOUDS OVER THE FAR NE PLAINS FROM KRTN EAST TO KCAO. EXPECT THIS AREA TO BURN OFF QUICKLY AFT SUNRISE. CURRENTLY SOME -TSRA EXITING EAST ALONG THE TX STATE LINE EXPECTED TO DIMINISH THRU 15Z...BUT THEN QUICKLY REDEVELOP AFT 19Z WHERE REMNANT BOUNDARIES WILL FOCUS INSTABILITY. CARRIED ONLY VCTS AT KTCC AND KROW SINCE CONFIDENCE NOT HIGH ENOUGH THAT ANY SPECIFIC SITE WILL ACTUALLY BE IMPACTED. FARTHER WEST MAINLY DEALING WITH MID LEVEL CLOUD DECKS AND A COUPLE VCSH BY LATE DAY. ANOTHER ROUND OF LOW CLOUDS IS POSSIBLE OVER THE FAR NE PLAINS TONIGHT WHERE THE BEST LOW LEVEL CONVERGENCE OCCURS. GUYER && .PREV DISCUSSION...340 AM MDT THU SEP 27 2012... THE EAST HALF OF THE STATE...ROUGHLY...WILL BE WHERE MUCH OF THE ACTION...ESPEC PCPN AND STORM INTENSITY...WILL BE OVER THE NEXT 2 TO 3 DAYS AS A FAIRLY DECENT COMBO OF JET RELATED DYNAMICS... EFFECTS OF A BACK DOOR FRONT AND POST FRONTAL UPSLOPE FLOW IMPACT NE AND PORTIONS OF E CENTRAL NM AND SOMEWHAT DEEPER AND PARTIALLY TROPICAL MOISTURE AFFECTS THE SE PORTION OF THE FCST AREA. FIRST OFF THERE IS A SLIGHT RISK OF SVR STORMS ACROSS NE AND FAR E CENTRAL NM THIS AFTERNOON AND INTO AT LEAST MID EVE. THOSE AREAS LOOKING AT SOME VEERING WITH HEIGHT OF WINDS WITH SOME INCREASE IN SPEEDS GOING UP AS WELL...THE SFC BOUNDARY WHICH COULD MIX BACK NE A BIT...BUT LIKELY STILL STAY SOMEWHERE IN NE NM...AS WELL AS DECENT LAPSE RATES OVER THIS AREA. THUS FEEL SPC OUTLOOK LOOKS PRETTY GOOD AND THUS ADDED THE SEVERE MENTION IN WX GRIDS FOR ROUGHLY RATON TO TUCUMCARI AND EASTWARD. KEPT APPROX SAME AREA IN THE RISK AREA INTO MID EVE...THEN ELIMINATED IT. BUT THAT WILL HAVE TO BE REEVALUATED LATER TODAY AS TO EXACT COVERAGE AREA AND HOW LONG IT WILL LINGER INTO/THRU THE EVE. IN THE SE WITH SOME INCREASE IN DEEP MOISTURE...WITH SOME TROPICAL INPUT...WILL SEE PERHAPS THE BEST POTENTIAL FOR LOCALLY HEAVY RAINFALL...THOUGH MORE LOCALIZED INSTANCES CERTAINLY POSSIBLE IN NE NM AS WELL WITH THE BETTER DYNAMICS AND MODEST TO MODERATE UPSLOPE FLOW THERE. AS IS NORMALLY THE CASE...ACTIVITY INTENSITY SHOULD DIMINISH SOME LATER TONIGHT...BUT FRONT MAY ADVANCE SOME TO S AND W AND THAT MAY ACTUALLY INCREASE COVERAGE SOMEWHAT ACROSS THE E. HOWEVER THE VERY LATEST NAM MODEL DATA IS MUCH LESS BULLISH ON BACK DOOR ADVANCEMENT FOR TONIGHT SO ANY MOISTURE REPLENISHMENT TO AND ESPECIALLY W OF CENTRAL MTN CHAIN NOW LOOKS MORE PROBLEMATIC. THUS LATER SHIFTS WILL WANT TO SEE IF THIS NEW TREND CONTINUES AND MAKE ANY NEEDED ADJUSTMENTS TO POPS AND QPF ETC ESPEC W OF CENTRAL MTN CHAIN FOR THE FRI TO SAT PERIOD. WITH THE TROPICAL MOISTURE GETTING SHUNTED MORE TO THE SE AND E OF THE STATE AS NW MID AND UPPER FLOW TAKES OVER...DEEPER MOISTURE OVER THE AREA WILL BE JUST A MEMORY FOR THE WEEKEND AND GRADUALLY...WITH THE EXCEPTION OF A COUPLE OR SO WEAK RIPPLES ALOFT IN THE NW TO INCREASINGLY N FLOW OVER WEEKEND...THERE WILL BE A DRYING TENDENCY ACROSS THE STATE WITH EVENTUALLY SOME DAYTIME SLIGHT TO MODERATE WARMING. AS EARLY AS MON THEN THROUGH MOST OF NEXT WEEK IT LOOKS TO BE A DRY PERIOD STATEWIDE AS DEWPOINTS PLUMMET AND HIGH PRESSURE ALOFT BECOMES MORE DOMINANT. DID GO A LITTLE BELOW MAJORITY OF GUIDANCE NUMBERS FOR MINIMUMS FROM MON ON TO ALLOW FOR THE MOSTLY CLEAR SKIES...LIGHT WINDS AND LENGTHENING NIGHTS. 43 .FIRE WEATHER... A BATTLE BETWEEN TROPICAL MOISTURE STREAMING NE OUT OF OLD MEXICO AND DRY AIR OOZING SE INTO THE NW HALF OF NM WILL SET THE STAGE FOR A CHALLENGING WIND AND RH FORECAST THRU THE WEEKEND. DAILY ROUNDS OF UPPER LEVEL DISTURBANCES EJECTING NE ACROSS THE REGION WILL WAFFLE THE LOW LEVEL MOISTURE AND BOUNDARIES OVER THE REGION COMPLICATING WHERE THE GRADIENT FOR WETTING RAINFALL SETS UP. CURRENTLY HEAVIER STORMS OVER THE E PLAINS ARE BRINGING SIGNIFICANT WETTING RAIN WITH RATHER LARGE FOOTPRINTS FOR QUAY...CURRY...AND ROOSEVELT COUNTIES. RECOVERIES RANGE FROM EXCELLENT ACROSS THE PLAINS TO GOOD ALONG THE AZ BORDER...WHICH WILL BE THE STORY THROUGH EARLY SUNDAY. LIKEWISE MIN RH VALUES WILL RANGE FROM THE TEENS AND 20S ALONG THE AZ BORDER TO THE 40S ALONG THE TX STATE LINE. THE BEST CHANCE AT THIS TIME FOR GOOD WETTING RAINFALL FOOTPRINTS WILL BE OVER THE SE HALF...WITH SOME POTENTIAL FOR MOIST OUTFLOW BOUNDARIES TO OOZE WEST INTO THE RIO GRANDE VALLEY FRIDAY FOR BETTER STORM CHANCES. VENT RATES WILL BE NEAR POOR ACROSS THE EAST AND GOOD OUT WEST AS HAINES VALUES FOLLOW SUIT WITH LOW VALUES OUT EAST AND MODERATE OUT WEST. A STRENGTHENING UPPER LEVEL HIGH PRESSURE SYSTEM ALONG THE WEST COAST WILL BEGIN INCREASING DRY NW FLOW OVER WESTERN NM SUNDAY THEN INTO THE EASTERN HALF BY MONDAY. A WEAK WAVE WILL BRING ONE FINAL SHOT OF LOW LEVEL MOISTURE INTO THE PLAINS ON A NORTHERLY WIND SHIFT. MODELS INDICATE A SIGNIFICANT DRY AIR INTRUSION FROM WEST TO EAST WITH THE UPPER HIGH...THUS DRYING OUT THE ENTIRE REGION CONSIDERABLY. MIN RH VALUES WILL FALL BACK INTO THE TEENS AND 20S EARLY NEXT WEEK HOWEVER RECOVERIES WILL STILL BE FAIR TO VERY GOOD. HIGH PRESSURE BUILDING OVER THE REGION WILL FAVOR CHILLY MIN TEMPS WITH MILD AFTERNOON HIGHS. STRONG MID SLOPE INVERSIONS WILL BEGIN TO ENTER THE PICTURE IN THIS SCENARIO. VENT RATES AS A RESULT FALL TO POOR FOR THE WEST AND REMAIN FAIR ACROSS THE EAST. GUYER && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ GUYER/43 ______________________________________________________________________ KABQ - Reference: ['consider more than 24 hrs out. looking at modis rgb air mass h2o'] 787 FXUS65 KABQ 230936 AFDABQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 336 AM MDT TUE OCT 23 2012 .DISCUSSION... UNSEASONABLY WARM WITH NEAR RECORD AND SOME RECORD BREAKING HIGHS...PARTICULARLY EAST..AND INCREASING WIND THROUGH WEDNESDAY THEN A BIG CHANGE TO COOLER/COLDER WEATHER. PRECIPITATION WILL STILL BE VERY PALTRY THOUGH AND LIMITED MAINLY TO THE NE QUARTER... THAT MAINLY DURING THE THU NIGHT TO FRI PERIOD. WARM AGAIN TODAY WITH A FEW NEAR RECORD HIGH TEMPERATURES IN THE EAST. SFC WINDS WILL BE UP A GOOD 5 TO AS MUCH AS 10 MPH ACROSS N CENTRAL AND NE NM. WINDS WILL REMAIN GUSTY OVER THE MOUNTAINTOPS TONIGHT. EVEN WARMER IN THE EAST ON WEDNESDAY WITH A NUMBER OF RECORD HIGHS LIKELY. WINDS TO BE HIGHER STILL WITH BREEZY TO WINDY CONDITIONS OVER THE MOUNTAINS AND NORTHEAST. STILL MAY BE SOME PATCHY ADVISORY LEVEL...OR NEARLY SO...WIND SPEEDS ACROSS NE THIRD OR SO OF NM...BUT STILL TOO CLOSE TO THE MARGINAL RANGE TO CONSIDER MORE THAN 24 HRS OUT. LOOKING AT MODIS RGB AIR MASS H2O VAPOR IMAGERY...THERE DOES APPEAR TO BE A LITTLE MTN WAVE ACTIVITY GOING ON OVER TO A SLIGHT DISTANCE E OF SANGRES...BUT WHILE ON THE WARMER SIDE OF THE UPPER TROUGH FOR NOW...NOT EXPECTING IT TO BE TOO MUCH OF A PROB. WILL NEED TO CONTINUE TO BE MONITORED. A POTENT SHORT WAVE TROUGH OR TWO MOVING THROUGH A LONG WAVE TROUGH...AND THE ASSOCIATED PACIFIC AND POLAR FRONTS...WILL THEN IMPACT NM WED NIGHT AND THU. TEMPERATURES THU WILL BE BE 10 TO 25 DEGREES BELOW NORMAL IN THE EAST AND ROUGHLY 5 TO 15 DEGREES COOLER IN THE NW. A REINFORCING SHOT OF CHILLY AIR THU NIGHT AND FRI WILL BRING EVEN LOWER TEMPERATURES TO THE FORECAST AREA. SADLY...IT DOES NOT LOOK LIKE MUCH PRECIPITATION COMBINING WITH THE COLDER AIR. A LITTLE SNOW IS POSSIBLE THU NIGHT THROUGH FRI NIGHT OVER THE NORTHERN MOUNTAINS AND NE...LIKELY AN INCH OR LESS LOWER TERRAIN. THE WEEKEND WILL BE DRY WITH A CHILLY SATURDAY FOLLOWED SOME WARMING FOR AT LEAST A FEW DAYS THEREAFTER. 43 && .FIRE WEATHER... CRITICAL FIRE WEATHER...A FEW HOURS OF LOW HUMIDITIES AND GUSTY WINDS DEVELOPING THIS AFTERNOON OVER THE NORTHEAST HIGHLANDS AND ADJACENT NORTHEAST PLAINS ACROSS SAN MIGUEL AND MORA COUNTIES. WIDESPREAD RED FLAG CONDITIONS DEVELOPING WEDNESDAY FROM THE CENTRAL MOUNTAIN CHAIN EAST TO THE TEXAS LINE MAINLY ALONG AND NORTH OF THE INTERSTATE 40 CORRIDOR. MODELS...IN GOOD AGREEMENT THROUGH THE UPCOMING WEEKEND AND INTO THE FIRST OF THE WORK WEEK. SOME DIFFERENCES EMERGING IN PATTERN EVOLUTION AND TIMING OF FEATURES MOVING THROUGH THE BROAD PATTERN FROM TUESDAY ONWARD. CIRCULATION ABOUT SYSTEM IN THE PACIFIC NORTHWEST WILL SUPPORT SOUTHWEST FLOW ACROSS NEW MEXICO...AS EMBEDDED SHORTWAVE AMPLIFIES OVER SOUTHERN CALIFORNIA EARLY WEDNESDAY. WAVE WILL DIG SOUTHEAST AND SHEAR RAPIDLY EASTWARD ON WEDNESDAY INTO THURSDAY...WITH FLOW ALOFT VEERING TO NORTHWEST TO WIND UP THE WORK WEEK. WEAKENING NORTHWEST FLOW WILL REMAIN OVER NEW MEXICO THROUGH THE WEEKEND AND INTO MONDAY. MODELS DIVERGING IN BRINGING NEXT SHORTWAVE OUT OF THE NORTHEAST PACIFIC AND INTO NEW MEXICO. GFS MODEL FASTER TO BRING WAVE INTO THE CENTRAL CALIFORNIA COAST ON TUESDAY...WITH ECMWF RUNNING ABOUT 36 HOURS LATER FOR TROUGH PUSH ONSHORE WEDNESDAY NIGHT. WILL KEEP EYE ON RUNS TO FOLLOW AND SEEK BETTER CONSENSUS. FOR TODAY...WARMING AND DRYING CONTINUING WITH HUMIDITIES FALLING TO NEAR 10 PCT IN THE EAST. DEEPENING SURFACE TROUGH FROM EASTERN COLORADO TO NORTHEAST NEW MEXICO WILL ACCELERATE AFTERNOON WIND SPEEDS OVER THE NORTHEAST...AND PRODUCE A COUPLE OF HOURS OF CRITICAL FIRE WEATHER CONDITIONS. EXPECT STRONGEST WINDS AND LOWEST HUMIDITIES OVER THE INTERSTATE 25 CORRIDOR ACROSS SAN MIGUEL AND MORA COUNTIES...WITH CONDITIONS IMPROVING AFTER SUNSET AS HUMIDITIES RECOVER. TEMPERATURES RUNNING UP TO 20 DEGREES ABOVE LATE OCTOBER NORMALS OVER THE EAST...WITH TEN DEGREES ABOVE NORMAL TYPICAL FOR THE WEST. NO VENTILATION ISSUES WITH ONLY FAIR HUMIDITY RECOVERIES OVERNIGHT. FOR WEDNESDAY...SURFACE LOW DEEPENING RAPIDLY OVER THE NORTHEAST PLAINS AS BASE OF DIGGING TROUGH MOVES ACROSS NEW MEXICO THROUGH THE DAY. GUSTY SOUTHWEST WINDS WILL DEVELOP ACROSS THE SUMMITS AND EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN...AND ACROSS THE ADJACENT PLAINS TO THE TEXAS BORDER. MINIMUM HUMIDITIES DROPPING ONCE AGAIN TO NEAR 10 PCT OVER THE AREA...AND BROAD AREA OF RED FLAG CONDITIONS WILL DEVELOP BY LATE MORNING GENERALLY FROM INTERSTATE 25 EASTWARD...AND INTERSTATE 40 NORTHWARD OVER THE NORTHEAST QUADRANT OF NEW MEXICO. WILL HOIST FIRE WEATHER WATCH WITH THE MORNING PACKAGE TO COVER. LITTLE CHANGE TO NEAR RECORD SETTING HIGH TEMPERATURES OVER THE EAST...RUNNING TO NEAR 20 DEGREES ABOVE LATE OCTOBER NORMALS...WITH TEMPERATURES TOPPING OUT TEN DEGREES ABOVE NORMAL IN THE WEST. NO VENTILATION PROBLEMS. MAINLY FAIR HUMIDITY RECOVERIES OVERNIGHT. FOR THURSDAY...COLD FRONT SWINGING RAPIDLY EAST AND SOUTH IN THE WAKE OF FAST MOVING WAVE AND ASSOCIATED SURFACE LOW. MAXIMUM TEMPERATURES WILL TAKE A 20 TO 30 DEGREE DROP OVER THE EAST...WITH MORE MODEST DECREASES IN THE WEST. MUCH COOLER AIR WILL BOOST EASTERN MINIMUM HUMIDITIES INTO THE UPPER TEENS AND 20S PCT...WHILE THE WEST REMAINS IN THE TEENS PCT. TEMPERATURES OVER THE NORTH WILL MAKE MAJOR SWING FROM THE HEAT TO 8 TO 15 DEGREES BELOW LATE OCTOBER NORMALS...AND NEAR NORMAL TEMPERATURES SOUTH OF INTERSTATE 40. DETERIORATING VENTILATION CONDITIONS OVER THE EASTERN PLAINS AND RIO GRANDE VALLEY THROUGH THURSDAY EVENING. SOME SHOWERS OF RAIN AND SNOW WILL DEVELOP OVERNIGHT OVER THE NORTHEAST...WITH MODEST SNOW ACCUMULATIONS OVER SANGRE DE CRISTO RANGE SUMMITS THROUGH EARLY FRIDAY MORNING. MUCH COLDER AIR IN PLACE WILL SET UP FREEZES OVER MUCH OF NORTHERN NEW MEXICO...WITH SUBFREEZING OVERNIGHT TEMPERATURES POSSIBLE OVER THE EAST MAINLY ALONG AND NORTH OF INTERSTATE 40. GOOD TO EXCELLENT HUMIDITY RECOVERIES OVERNIGHT OVER THE EAST...FAIR TO GOOD OVER THE WEST. OUTLOOK...FRIDAY THROUGH WEEKEND...BROAD WARMING TREND THROUGH SUNDAY WITH TEMPERATURES REBOUNDING BACK TOWARD LATE OCTOBER NORMALS. A VERY CHILLY FRIDAY OVERNIGHT SHOULD DELIVER HARD FREEZES TO MOST ALL OF NORTHERN AND CENTRAL NEW MEXICO. LAST OF THE RAIN AND SNOW SHOWERS WILL TAPER OFF THROUGH FRIDAY NIGHT WITH PRETTY MODEST SNOW ACCUMULATIONS OVER THE SUMMITS AND SLOPES OF THE NORTHEAST HIGHLANDS...AND SOME SNOW WORKING OUT OVER THE NORTHEAST PLAINS INTO SATURDAY MORNING. GENERAL DRYING TREND UNDERWAY WILL DROP MINIMUM HUMIDITIES BACK INTO THE 20S PCT OVER THE EAST AND CENTRAL...WITH TEENS PCT OVER THE WEST. MARGINAL VENTILATION CONDITIONS FRIDAY IMPROVING SOMEWHAT THROUGH THE WEEKEND...WITH CONDITIONS REMAINING POOR OVER THE EAST AND NORTHEAST...AND OVER THE SOUTH CENTRAL MOUNTAINS. SHY && .AVIATION... 06Z TAF CYCLE VFR CONDITIONS WILL PREVAIL DURING THE NEXT 24 HOURS. AS THE BASE OF A BROAD UPPER LEVEL TROUGH SLOWLY APPROACHES THE REGION FROM THE GREAT BASIN...WEST WINDS WILL INCREASE IN THE HIGHER PEAKS AND IN THE LEE OF THE SAN JUAN AND SANGRE DE CRISTO MOUNTAINS LATE TONIGHT THROUGH 18Z TUESDAY. LCL GUSTS TO 45 KTS ARE POSSIBLE...MAINLY FROM NEAR KRTN SOUTH TO NEAR KLVS. GUSTY W TO SW WINDS WILL DEVELOP ONCE AGAIN TUESDAY AFTERNOON NEAR KGUP AND FROM KLVS...KCQC TO KTCC...WHERE GUSTS TO 35KTS ARE POSSIBLE UNTIL AROUND SUNSET. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 73 39 70 32 / 0 0 0 0 DULCE........................... 68 28 67 26 / 0 0 5 5 CUBA............................ 70 37 69 31 / 0 0 0 5 GALLUP.......................... 71 36 68 28 / 0 0 0 0 EL MORRO........................ 69 34 67 26 / 0 0 0 0 GRANTS.......................... 73 38 71 31 / 0 0 0 0 QUEMADO......................... 72 41 71 35 / 0 0 0 0 GLENWOOD........................ 78 39 77 34 / 0 0 0 0 CHAMA........................... 64 31 62 29 / 5 0 5 5 LOS ALAMOS...................... 69 46 69 41 / 0 0 0 0 PECOS........................... 68 43 68 39 / 0 0 0 0 CERRO/QUESTA.................... 68 38 67 34 / 0 0 5 5 RED RIVER....................... 61 34 59 29 / 0 0 5 5 ANGEL FIRE...................... 64 35 63 28 / 0 0 0 5 TAOS............................ 69 34 68 30 / 0 0 0 5 MORA............................ 70 43 69 37 / 0 0 0 5 ESPANOLA........................ 74 39 73 33 / 0 0 0 0 SANTA FE........................ 71 42 70 37 / 0 0 0 0 SANTA FE AIRPORT................ 73 43 72 37 / 0 0 0 0 ALBUQUERQUE FOOTHILLS........... 73 48 73 42 / 0 0 0 0 ALBUQUERQUE HEIGHTS............. 75 51 75 45 / 0 0 0 0 ALBUQUERQUE VALLEY.............. 78 46 78 42 / 0 0 0 0 ALBUQUERQUE WEST MESA........... 77 48 77 43 / 0 0 0 0 LOS LUNAS....................... 78 45 78 41 / 0 0 0 0 RIO RANCHO...................... 76 48 76 42 / 0 0 0 0 SOCORRO......................... 82 49 83 44 / 0 0 0 0 SANDIA PARK/CEDAR CREST......... 70 46 71 40 / 0 0 0 0 TIJERAS......................... 72 47 72 41 / 0 0 0 0 MORIARTY/ESTANCIA............... 74 40 73 35 / 0 0 0 0 CLINES CORNERS.................. 74 44 73 38 / 0 0 0 0 GRAN QUIVIRA.................... 76 47 76 42 / 0 0 0 0 CARRIZOZO....................... 79 48 79 45 / 0 0 0 0 RUIDOSO......................... 73 49 74 45 / 0 0 0 0 CAPULIN......................... 77 42 77 35 / 0 0 0 5 RATON........................... 80 39 80 35 / 0 0 0 5 SPRINGER........................ 81 42 79 35 / 0 0 0 5 LAS VEGAS....................... 77 43 78 38 / 0 0 0 0 CLAYTON......................... 85 49 83 36 / 0 0 0 5 ROY............................. 81 47 80 39 / 0 0 0 0 CONCHAS......................... 86 50 85 42 / 0 0 0 0 SANTA ROSA...................... 84 50 84 44 / 0 0 0 0 TUCUMCARI....................... 88 52 89 45 / 0 0 0 0 CLOVIS.......................... 86 51 87 47 / 0 0 0 0 PORTALES........................ 86 50 87 47 / 0 0 0 0 FORT SUMNER..................... 87 51 89 47 / 0 0 0 0 ROSWELL......................... 90 53 93 50 / 0 0 0 0 PICACHO......................... 86 50 85 46 / 0 0 0 0 ELK............................. 79 52 78 47 / 0 0 0 0 && .ABQ WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR THE FOLLOWING ZONES...NMZ103-104-107-108. && $$ 43 ______________________________________________________________________ KABQ - Reference: ['well as from moriarty to tucumcari. modis rgb airmass water vapor'] 282 FXUS65 KABQ 232114 AFDABQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 314 PM MDT TUE OCT 23 2012 .DISCUSSION... ONE MORE WARM DAY ON WED THEN MUCH COOLER...COLDER THU AND FRI. STRONG WINDS LATER TON THROUGH WED NIGHT OVER THE NRN AND CNTRL MOUNTAINS ONTO THE ADJACENT HIGH PLAINS. MODERATE SW FLOW ALOFT HELPING TO GENERATE DECENT SURFACE WINDS ALONG THE E SLOPES OF THE SANGRES TO LAS VEGAS AND RATON...AS WELL AS FROM MORIARTY TO TUCUMCARI. MODIS RGB AIRMASS WATER VAPOR SATELLITE LOOP SHOWING MOUNTAIN WAVE ACTION CONTINUING OVER NE NM. MEANWHILE TEMPERATURES HAVE SOARED INTO THE 60S IN THE MOUNTAINS AND 70S TO NEAR 90 ACROSS THE LOWLANDS...ALL WELL ABOVE NORMAL. A FEW RECORDS WILL LIKELY BE BROKEN...WITH A RECORD HIGH ALREADY IN RATON. WINDS EXPECTED TO DROP EARLY TONIGHT ONLY TO INCREASE AGAIN LATE TONIGHT OVER THE SANGRE DE CRISTO MOUNTAIN TOPS AND PLOW DOWN THE E SLOPES ONTO THE NE HIGHLANDS EARLY WED. THE CENTRAL HIGHLANDS WILL ALSO SEE STRONG WINDS WED. WE WILL ISSUE A WIND ADVISORY FOR THE SANGRE DE CRISTO MOUNTAIN TOP ZONES AND E SLOPES...RATON RIDGE/JOHNSON MESA FOR LATE TON THROUGH WED AND FOR THE CNTRL... NE AND FAR NE HIGHLANDS WED AM THROUGH WED PM. THE OTHER WEATHER STORY WED WILL BE THE EXCEPTIONALLY WARM TEMPERATURES WITH MANY NEAR RECORD OR RECORD BREAKING HIGHS. THE WINDS WILL REMAIN STRONG OVER THE SANGRES WED NIGHT AND INCREASE OVER THE CNTRL MOUNTAINS TO LIKELY ADVISORY LEVELS. MEANWHILE A POTENT SHORT WAVE TROUGH WILL BE PASSING TO OUR N WED NIGHT WITH A PACIFIC COLD FRONT RACING ACROSS WRN NM AND A POLAR FRONT SLAMMING INTO THE NE PART OF THE STATE. THE TWO WILL COMBINE TO BRING MUCH COOLER...COLDER TEMPERATURES TO THE FORECAST AREA THU...INCLUDING NEARLY 40 DEGREES COLDER AT CLAYTON. WINDS WILL SUBSIDE DURING THE DAY THU. CHILLY AIR WILL CONTINUE TO POUR INTO THE STATE THU NIGHT WITH SOME LOW LEVEL MOISTURE OVER THE NE. ENOUGH TO PERHAPS CREATE SOME LIGHT SNOW ALONG THE E SLOPES OF THE SANGRES AND THE FAR NE HIGHLANDS AND PLAINS THU NIGHT INTO FRI. IT WILL BE CHILLY ON FRI WITH HIGHS 10 TO 20 DEGREES BELOW NORMAL...EXCEPT IN THE SW. A WIDESPREAD FREEZE...HARD FREEZE IS LIKELY FRI NIGHT. THE WEEKEND WILL START CHILLY BUT TEMPERATURES WILL MODERATE ESPECIALLY ON SUN. IT WILL BE DRY AREA WIDE WITH LOTS OF SUNSHINE AND NOT TOO MUCH WIND. CHJ && .FIRE WEATHER... LOCALIZED AREAS TO THE LEE OF THE SANGRE DE CRISTOS AND SANDIAS CURRENTLY EXPERIENCING SOME RED FLAG CONDITIONS WITH GUSTY WINDS AND LOW HUMIDITY. THE CONDITIONS WILL LESSEN AS THE SUN GOES DOWN BUT RETURN AND EXPAND WEDNESDAY. THIS IS IN RESULT OF AN APPROACHING PACIFIC TROUGH WHICH WILL CROSS OVER THE ROCKIES WEDNESDAY/WEDNESDAY NIGHT. MUCH COOLER AIR WILL FOLLOW AND MOST LIKELY PROVIDE A FAIRLY WIDESPREAD FREEZE EVENT TO NORTHERN AND CENTRAL AREAS. THE UPPER WIND FLOW IS PROJECTED TO INCREASE OVERNIGHT AND BUFFET THE HIGHER PEAKS...ESPECIALLY WITH WESTERLY EXPOSURE. AT THE SAME TIME...A MODERATE TO STRONG MID LEVEL DRY SLOT WILL BE DRAPED OVER MOST OF THE AREA. THIS MEANS THAT HUMIDITY RECOVERIES WILL BE MODEST AT BEST EXCEPT FOR THE FAR SOUTHEAST PLAINS WHERE GOOD RECOVERIES ARE EXPECTED. THIS IS WHERE THE MODELS SHOW A FAIRLY PRONOUNCED LOW LEVEL MOISTURE INTRUSION. THIS WILL BE SHORT LIVED AS HUMIDITIES FALL BACK INTO THE TEENS ACROSS MOST OF THE AREA WEDNESDAY AFTERNOON. BASED ON THE MID LEVEL DRY SLOT FORECAST FROM THE MODEL AS WELL AS INCREASED MECHANICAL MIXING...LOWERED DEWPOINT TEMPERATURES BELOW GUIDANCE LEVELS TO THE LEE OF THE CENTRAL MOUNTAINS. THIS IS WHERE HUMIDITY READINGS SHOULD FALL INTO THE UPPER SINGLE DIGITS. THESE LOWER HUMIDITIES COUPLED WITH STRONG WINDS SHOULD PROVIDE CRITICAL FIRE WEATHER CONDITIONS OVER A FAIRLY EXPANSIVE AREA ACROSS THE EASTERN THIRD TO HALF. THIS WILL BE COMBINED WITH WELL ABOVE TO NEAR RECORD LEVEL TEMPERATURES. HAINES VALUES WILL BE A SMATTERING OF 4 TO 5/S SO NOT A CLASSIC SPRING CASE BY ANY MEANS. REGARDLESS...UPGRADED THE WATCH TO A WARNING FOR THE FOUR EASTERN ZONES. THIS INCLUDES PORTIONS OF THE ACTUAL MOUNTAIN AREAS FOUND WITHIN THE SANDIA/MANZANOS AS WELL AS SANGRES. MODELS DO SHOW THE PEAK WINDS ALOFT LATER WEDNESDAY AFTERNOON INTO THE OVERNIGHT HOURS. MODELS ARE FAIRLY CONSISTENT WITH THE MAIN TROUGH PASSAGE WEDNESDAY NIGHT. THIS IS WHEN THE FLOW TURNS FROM A WEST/SOUTHWEST TO A WEST/NORTHWEST AND ULTIMATELY NORTHWESTERLY. THE MAIN COLD FRONTAL PASSAGE WILL BE AFTER MIDNIGHT. THE MAIN WIND ENVELOPE WILL THEN SHIFT SOUTHWARD AND AFFECT THE SANDIA/MANZANO MOUNTAINS AND AREAS TO THE EAST AS STRONG MOUNTAIN WAVE ACTION IS SURE TO MATERIALIZE. A VERY STRONG TROUGH INDUCED PACIFIC MID LEVEL DRY SLOT WILL ALSO FOLLOW IN THE WAKE AND CONSIDERABLY DROP DEWPOINTS. WENT BELOW GUIDANCE ONCE AGAIN ACROSS THE HIGHER PEAKS AND AREAS TO THE LEE OF THE CENTRAL MOUNTAINS. ESPECIALLY ALONG AND SOUTH OF I40. RECOVERIES AS A RESULT WILL BE PRETTY POOR SOUTHERN HALF OF THE FORECAST AREA. MODERATE TO POOR ACROSS THE NORTHERN HALF. THE ONLY EXCEPTION BEING ACROSS THE FAR NORTHEAST PLAINS WHERE WE ARE LOOKING AT SOME GOOD RECOVERIES AS THE WIND SHIFTS DIRECTION THERE. BELOW TO WELL BELOW NORMAL TEMPERATURES ARE EXPECTED FOR MOST OF THE FORECAST AREA ON THURSDAY. PERHAPS MORE NEAR NORMAL ACROSS THE FAR SOUTH. THE PACIFIC DRY SLOT SHOULD WEAKEN SOME AND SAG SOUTHWARD BASED ON LATEST MODEL PROJECTIONS BUT NOT BEFORE DROPPING HUMIDITY READINGS INTO THE SINGLE DIGITS ACROSS THE SOUTHWEST THIRD. MUCH HIGHER HUMIDITY LEVELS ARE EXPECTED ACROSS THE EASTERN PLAINS DUE TO THE MORE EASTERLY WIND THERE. CRITICAL FIRE WEATHER GROWTH CONDITIONS ARE NOT ANTICIPATED FOR THURSDAY. ESPECIALLY AS MIXING HEIGHTS DROP PRETTY SIGNIFICANTLY. MUCH MORE STABLE AIR NEAR THE SURFACE EVEN THOUGH THE WINDS ALOFT WILL STILL BE FAIRLY STRONG. THE WIND GRADIENT RELAXES SOME FRIDAY AND INTO THE WEEKEND. THIS IS SUPPORTED BY ALL OF THE MODELS. GRADUAL WARMING TREND WILL TAKE PLACE BUT WILL BE SLOWER DUE TO THE TIME OF YEAR. SUN ANGLE IS CERTAINLY LESSENING. A WIDESPREAD FREEZE EVENT IS EXPECTED FRIDAY MORNING AS A RESULT OF CLEARER SKIES...DECREASING WIND AND THE VERY LOW DEWPOINTS EXPECTED TO BE IN PLACE. VENTILATION WILL CERTAINLY TAKE A HIT DURING THIS PERIOD BUT SHOULD IMPROVE SOME ON SUNDAY AS TEMPERATURES REBOUND. THE OUTLOOK FOR THE EARLIER HALF OF NEXT WEEK LOOKS PROMISING FOR RX BURNS BASED ON THE FLOW PATTERN PROJECTED BY BOTH THE GFS AND ECMWF. FAIRLY MODEST WIND ALOFT UNDER A DRIER NORTHWEST FLOW. VENTILATION SHOULD BE DECENT ENOUGH...ESPECIALLY AS IT CONCERNS MAX RATES. ALL EYES WILL BE ON THE NEXT PACIFIC TROUGH WHICH IS PROJECTED FOR LATER IN THE WEEK. WINDS WOULD INCREASE AHEAD OF IT SIMILAR TO THIS LAST ONE. MODELS HAVE BEEN JUMPING AROUND ON THE INTENSITY AND TIMING SO CONFIDENCE CERTAINLY DEGRADES THE LATTER HALF OF NEXT WEEK. 50 && .AVIATION... 18Z TAF CYCLE WIND WILL BE THE MAIN WEATHER HAZARD NEXT 24 HOURS. LOOKING FOR GUSTS BETWEEN 30 TO 35 KT AT GUP...LVS AND TCC AT TIMES THIS AFTERNOON. STRONGER WIND FLOW EXPECTED ON WEDNESDAY AS THE MAIN PORTION OF THE PACIFIC TROUGH PASSES OVERHEAD. THIS IS WHEN ALL TERMINAL SITES SHOULD SEE GUSTS BETWEEN 30 TO 35 KT AND MOST LIKELY HIGHER ACROSS THE NORTHEAST HALF. SIGNIFICANT DISCREPANCIES IN THE MOS GUIDANCE AT ABQ/SAF ON WEDNESDAY SO HOPE TO GET A CLEARER PICTURE AS WE GET CLOSER TO WEDNESDAY AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 41 69 31 57 / 0 0 0 0 DULCE........................... 28 67 25 53 / 0 5 5 5 CUBA............................ 37 70 30 57 / 0 0 5 0 GALLUP.......................... 34 68 24 58 / 0 0 0 0 EL MORRO........................ 33 68 24 55 / 0 0 0 0 GRANTS.......................... 37 71 29 61 / 0 0 0 0 QUEMADO......................... 40 72 33 64 / 0 0 0 0 GLENWOOD........................ 39 77 32 71 / 0 0 0 0 CHAMA........................... 31 63 28 49 / 0 5 5 5 LOS ALAMOS...................... 45 70 40 56 / 0 0 0 0 PECOS........................... 44 68 38 53 / 0 0 0 0 CERRO/QUESTA.................... 38 68 34 54 / 0 5 5 5 RED RIVER....................... 34 60 27 44 / 0 5 5 5 ANGEL FIRE...................... 35 64 26 47 / 0 0 5 5 TAOS............................ 35 68 29 56 / 0 0 5 5 MORA............................ 44 69 37 52 / 0 0 5 5 ESPANOLA........................ 38 74 32 62 / 0 0 0 0 SANTA FE........................ 42 71 36 58 / 0 0 0 0 SANTA FE AIRPORT................ 41 74 36 60 / 0 0 0 0 ALBUQUERQUE FOOTHILLS........... 47 74 43 62 / 0 0 0 0 ALBUQUERQUE HEIGHTS............. 50 76 45 63 / 0 0 0 0 ALBUQUERQUE VALLEY.............. 45 78 41 65 / 0 0 0 0 ALBUQUERQUE WEST MESA........... 47 78 43 64 / 0 0 0 0 LOS LUNAS....................... 42 79 39 67 / 0 0 0 0 RIO RANCHO...................... 47 77 42 64 / 0 0 0 0 SOCORRO......................... 48 84 44 74 / 0 0 0 0 SANDIA PARK/CEDAR CREST......... 46 72 40 62 / 0 0 0 0 TIJERAS......................... 46 73 40 64 / 0 0 0 0 MORIARTY/ESTANCIA............... 38 74 33 65 / 0 0 0 0 CLINES CORNERS.................. 45 74 37 62 / 0 0 0 0 GRAN QUIVIRA.................... 46 77 41 64 / 0 0 0 0 CARRIZOZO....................... 47 80 45 69 / 0 0 0 0 RUIDOSO......................... 47 75 44 65 / 0 0 0 0 CAPULIN......................... 42 77 33 43 / 0 0 5 5 RATON........................... 40 80 35 46 / 0 0 5 5 SPRINGER........................ 43 80 35 52 / 0 0 5 5 LAS VEGAS....................... 46 78 38 57 / 0 0 0 5 CLAYTON......................... 50 86 37 48 / 0 0 5 5 ROY............................. 48 82 39 48 / 0 0 0 5 CONCHAS......................... 51 87 42 57 / 0 0 0 5 SANTA ROSA...................... 50 85 44 63 / 0 0 0 5 TUCUMCARI....................... 53 92 45 59 / 0 0 0 5 CLOVIS.......................... 51 89 47 63 / 0 0 0 5 PORTALES........................ 50 89 47 66 / 0 0 0 5 FORT SUMNER..................... 51 91 47 68 / 0 0 0 5 ROSWELL......................... 51 94 50 76 / 0 0 0 5 PICACHO......................... 49 86 46 72 / 0 0 0 0 ELK............................. 50 79 46 70 / 0 0 0 0 && .ABQ WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 11 AM TO 7 PM MDT WEDNESDAY FOR THE FOLLOWING ZONES...NMZ103-104-107-108. WIND ADVISORY FROM 4 AM TO 6 PM MDT WEDNESDAY FOR THE FOLLOWING ZONES...NMZ512>515-527. WIND ADVISORY FROM 9 AM TO 6 PM MDT WEDNESDAY FOR THE FOLLOWING ZONES...NMZ523-528-529. && $$ 40/50 ______________________________________________________________________ KABQ - Reference: ['snow cover visible on the 1741z modis rgb snow product sunday will'] 582 FXUS65 KABQ 121022 AFDABQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 322 AM MST MON NOV 12 2012 .DISCUSSION... CLEAR SKIES AND VERY DRY AIR IN PLACE ACROSS THE REGION ARE PROVIDING TWO KEY INGREDIENTS FOR COLD TEMPERATURES...HOWEVER AS OF 3 AM WINDS STILL HAVE NOT DECOUPLED ENOUGH IN MANY AREAS. SOME RECORDS ARE LIKELY FOR NORTHERN AND WESTERN SITES HOWEVER UNLESS THE THIRD CRITICAL ELEMENT OF LIGHT WINDS TAKES SHAPE IN THE NEXT COUPLE HOURS MOST OF THE REGION WILL REMAIN ABOVE RECORD TERRITORY. THE E PLAINS ARE CURRENTLY AS MUCH AS 10F HIGHER THAN EXPECTED FOR THIS HOUR SO CONFIDENCE IS NOT AS HIGH. DESPITE THESE FACTORS IT IS STILL VERY COLD FOR MID NOVEMBER. THE FORECAST FOR THIS WEEK WILL FEATURE MODERATING TEMPS...PERIODIC CLOUD COVER...AND GENERALLY LIGHT WINDS WITHIN QUASI-ZONAL FLOW. LOW LEVEL INVERSION EFFECTS WILL MAKE FOR SOME INTERESTING TEMPERATURE PATTERNS AS VALLEY LOCALES MAY BE A COUPLE DEGREES COOLER THAN MID SLOPE AREAS FOR MAX TEMPS...ESPECIALLY TODAY AND TUESDAY. AN AREA OF SNOW COVER VISIBLE ON THE 1741Z MODIS RGB SNOW PRODUCT SUNDAY WILL CORRESPOND TO THE COLDEST TEMPS THRU THE NEXT COUPLE DAYS TIL SNOW MELTS. CONFIDENCE IN THE EXTENDED FORECAST BEYOND THURSDAY IS LOW. THE LATEST WATER VAPOR LOOP SHOWS A VERY IMPRESSIVE FETCH OF MID AND UPPER LEVEL CLOUD COVER ADVANCING NE OUT OF THE SUBTROPICAL PACIFIC TOWARD THE SW CONUS. GOES HIGH DENSITY WIND DATA SHOWS A 130-150 KT SUBTROPICAL JET WITHIN THIS CLOUD COVER. IT IS ALSO IMPORTANT TO NOTE THAT THE WAVE TRAIN IS BECOMING VERY ACTIVE OVER THE OPEN PACIFIC AND QUITE AMPLIFIED AS WELL. OPERATIONAL FORECAST GUIDANCE AND ENSEMBLES HAVE BEEN UNSTABLE WITH RESPECT TO SEVERAL OF THESE FEATURES SO THERE WILL LIKELY BE SOME CHALLENGES AS WE PROGRESS INTO THE END OF THIS WEEK INTO EARLY NEXT WEEK. FOR NOW HAVE JUST LEFT SLIGHT CHANCE POPS FOR MUCH OF THE NORTHERN AND WESTERN HIGH TERRAIN. GUYER && .FIRE WEATHER... VERY DRY AIRMASS IN PLACE ACROSS N AND CENTRAL NM FOR AT LEAST THE NEXT 2 OR 3 DAYS BEFORE ANY SIGNIFICANT MOISTENING SNEAKS IN. AFTN HIGH TEMPERATURES THOUGH WILL BEGIN A WARMING TREND TODAY AND ACCELERATING SOME TUE AS NM WILL BE UNDER A WEAK RIDGE/ZONAL FLOW ALOFT. HIGHS TODAY THOUGH STILL A GOOD 5 TO 15 DEGREES BELOW AVERAGE...EVEN A BIT MORE ACROSS REMAINING LOWER TERRAIN SNOW COVERED AREAS IN THE WEST...BUT CLIMB TO WITHIN A FEW DEGREES OF SEASONAL NORMS TUE EXCEPT IN THE LATTER MENTIONED AREA. VENTILATION POOR FOR THE MOST PART TODAY DUE TO MUCH LIGHTER WINDS SFC AND ALOFT AND MORN INVERSIONS BEING SLOWER TO BREAK. VENTILATION IS EXPECTED TO IMPROVE SLIGHTLY TO MODERATELY FROM E TO W TUE AND WED WITH SOME SFC LEE TROUGHING DEVELOPING. HOWEVER...VENTILATION IN THE WEST WILL CONTINUE TO BE INFLUENCED BY INVERSIONS AND THUS WILL REMAIN POOR TO LOCALLY FAIR MOST AREAS. LOCALES IN THE WESTERN MOUNTAINS THAT RECEIVED DECENT WEEKEND SNOW WILL SEE LOCALLY GOOD TO VERY GOOD RH RECOVERIES AGAIN TONIGHT IF AT LEAST SOME PATCHY SNOW MANAGES TO LINGER THROUGH THE DAY TODAY. OTHERWISE...THE SE TWO THIRDS OF THE AREA WILL EXPERIENCE POOR OVERNIGHT RECOVERIES NEXT COUPLE OF NIGHTS...WITH MIN RH VALUES RANGING FROM 7 TO 15 PERCENT BOTH OF THE NEXT 2 AFTNS. WED TEMPERATURES FINALLY WARM TO NEAR AND A LITTLE ABOVE SEASONAL NORMS OVER MOST OF THE FORECAST AREA WEDNESDAY...BUT MAY DROP BACK A LITTLE BELOW NORMAL VALUES IN E AND PORTIONS OF CENTRAL NM BY FRI DUE TO WEAK BACK DOOR FRONT. VENTILATION FINALLY IMPROVES TO FAIR OR BETTER ACROSS MOST OF THE WEST FRI...BUT NOT SO GREAT IN EAST BEHIND THE WEAK FRONT. RIGHT NOW...MOST OF THE WEEK LOOKS DRY EXCEPT FOR SMALL CHANCES FOR SHOWERS BY FRI OVER MAINLY THE WESTERN AND NORTHERN HIGH TERRAIN ASSOCIATED WITH AN APPROACHING DISTURBANCE. 43 && .AVIATION... 06Z TAF CYCLE VFR CONDITIONS WILL PREVAIL DURING THE NEXT 24 HOURS. LIGHT DRAINAGE OR CALM WINDS ARE EXPECTED AT ALL TAF SITES OVERNIGHT. LIGHT SOUTH WINDS WILL DEVELOP MONDAY AFTERNOON EAST OF THE CENTRAL MOUNTAIN CHAIN AS SURFACE HIGH PRESSURE SLIDES EAST INTO NORTHERN TEXAS. ELSEWHERE...LIGHT AND VARIABLE WINDS WILL REMAIN THE RULE THROUGH MONDAY EVENING. 33 && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 42 18 48 21 / 0 0 0 0 DULCE........................... 39 7 47 14 / 0 0 0 0 CUBA............................ 48 13 51 14 / 0 0 0 0 GALLUP.......................... 38 8 46 12 / 0 0 0 0 EL MORRO........................ 35 -1 41 5 / 0 0 0 0 GRANTS.......................... 39 15 49 16 / 0 0 0 0 QUEMADO......................... 39 16 45 21 / 0 0 0 0 GLENWOOD........................ 58 16 63 19 / 0 0 0 0 CHAMA........................... 39 17 43 21 / 0 0 0 0 LOS ALAMOS...................... 44 27 52 29 / 0 0 0 0 PECOS........................... 45 22 51 25 / 0 0 0 0 CERRO/QUESTA.................... 45 15 50 20 / 0 0 0 0 RED RIVER....................... 38 18 41 17 / 0 0 0 0 ANGEL FIRE...................... 43 19 44 17 / 0 0 0 0 TAOS............................ 44 12 50 14 / 0 0 0 0 MORA............................ 47 18 52 21 / 0 0 0 0 ESPANOLA........................ 44 14 53 17 / 0 0 0 0 SANTA FE........................ 47 24 51 29 / 0 0 0 0 SANTA FE AIRPORT................ 45 20 53 23 / 0 0 0 0 ALBUQUERQUE FOOTHILLS........... 47 29 55 34 / 0 0 0 0 ALBUQUERQUE HEIGHTS............. 46 27 55 29 / 0 0 0 0 ALBUQUERQUE VALLEY.............. 45 24 55 27 / 0 0 0 0 ALBUQUERQUE WEST MESA........... 47 23 56 25 / 0 0 0 0 LOS LUNAS....................... 45 19 56 22 / 0 0 0 0 RIO RANCHO...................... 47 23 55 25 / 0 0 0 0 SOCORRO......................... 54 22 59 28 / 0 0 0 0 SANDIA PARK/CEDAR CREST......... 46 24 48 29 / 0 0 0 0 TIJERAS......................... 45 22 51 29 / 0 0 0 0 MORIARTY/ESTANCIA............... 47 12 55 16 / 0 0 0 0 CLINES CORNERS.................. 47 22 54 27 / 0 0 0 0 GRAN QUIVIRA.................... 49 24 54 29 / 0 0 0 0 CARRIZOZO....................... 53 22 58 25 / 0 0 0 0 RUIDOSO......................... 49 27 54 33 / 0 0 0 0 CAPULIN......................... 43 24 55 24 / 0 0 0 0 RATON........................... 46 15 57 18 / 0 0 0 0 SPRINGER........................ 47 16 58 20 / 0 0 0 0 LAS VEGAS....................... 46 20 57 23 / 0 0 0 0 CLAYTON......................... 47 28 59 29 / 0 0 0 0 ROY............................. 44 21 57 23 / 0 0 0 0 CONCHAS......................... 52 25 64 27 / 0 0 0 0 SANTA ROSA...................... 52 24 65 26 / 0 0 0 0 TUCUMCARI....................... 54 27 63 27 / 0 0 0 0 CLOVIS.......................... 52 27 57 30 / 0 0 0 0 PORTALES........................ 53 26 59 27 / 0 0 0 0 FORT SUMNER..................... 51 25 59 28 / 0 0 0 0 ROSWELL......................... 56 27 62 30 / 0 0 0 0 PICACHO......................... 55 27 61 30 / 0 0 0 0 ELK............................. 52 28 59 32 / 0 0 0 0 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ______________________________________________________________________ --- Site: KABR --- --- Site: KAKQ --- KAKQ - Reference: ['been seen in low light visible satellites images. therefore...still'] 518 FXUS61 KAKQ 071922 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 322 PM EDT TUE AUG 7 2012 .SYNOPSIS... A FRONTAL BOUNDARY WILL REMAIN NEARLY STATIONARY ACROSS THE REGION INTO WEDNESDAY MORNING...THEN SLOWLY MOVES OFF THE COAST WEDNESDAY NIGHT. A MORE SUBSTANTIAL LOW PRESSURE SYSTEM WILL IMPACT THE MID ATLANTIC REGION FRIDAY INTO SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... A STATIONARY FRONT WILL REMAIN DRAPED OVER NRN PORTIONS OF THE FA THROUGH TONIGHT. VERY LITTLE CHANGE TO OVERALL H85 WX PATTERN WITH THE EXCEPTION OF A TROUGH DEVELOPING OVER THE APPALACHIANS OF WV/VA. ALTHOUGH SHOWERS AND THUNDERSTORMS HAVE BEEN AT A MINIMUM EARLY THIS AFTERNOON...SOME CLEARING TO THE SOUTH AND WEST SHOULD CREATE JUST ENOUGH INSTABILITY FOR THUNDERSTORMS TO DEVELOP/FILL IN FROM SOUTHWEST TO NORTHEAST AS THE LATE AFTERNOON/EARLY EVENING PROGRESSES. BEST SHORTWAVE ENERGY LIES TO THE SOUTH IN SRN NC BUT IS EXPECTED ROTATE OUT OVER THE NC OUTER BANKS AREA RATHER THAN INTO NE NC. A WEAK AREA OF MOISTURE CONVERGENCE SITS OVER THE LOWER EASTERN SHORE AND ACROSS SE VA WHERE HIGHER STORM TOPS HAVE BEEN SEEN IN LOW LIGHT VISIBLE SATELLITES IMAGES. THEREFORE...STILL EXPECTING BEST PRECIP/STORM CHANCES TO BE ACROSS SRN/SE VA AND NE NC. MAIN THREAT CONTINUES TO BE FROM HEAVY RAIN DUE TO A HUMID AIRMASS AND TRAINING OF STORMS WHICH MAY CAUSE LOCALIZED FLOODING PROBLEMS...ESPECIALLY IN AREAS WITH POOR DRAINAGE AS WELL AS IN LOCATIONS THAT EXPERIENCED UPWARDS OF 2 INCHES OF RAINFALL FROM TRAINING STORMS YESTERDAY. PRECIP SHOULD TAPER OFF FROM WEST TO EAST LATER TONIGHT WITH LINGERING SHOWERS AND ISO-SCT THUNDERSTORMS CLOSER TO THE COAST. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... THE FRONT WILL AGAIN BE NEARLY STATIONARY OVER THE FA ON WEDNESDAY AND THEN SLOWLY DISSIPATE OFF THE COAST WEDNESDAY NIGHT...KEEPING AN UNSETTLED WX PATTERN OVER THE MID ATLANTIC REGION. BEST PRECIP/STORM CHANCES WILL CONTINUE OVER SE VA AND NE NC WHERE FAVORABLE LIFT/ENERGY RESIDES...SLIGHT CHANCE POPS EXPECTED NORTH AND WEST OF THESE AREAS. HIGH TEMPERATURES WILL HOVER NEAR SEASONAL NORMALS IN THE MID-UPPER 80S. A LEE TROUGH DEVELOPS OVER THE REGION ON THURSDAY. THE TROUGH WILL HELP TO BOOST TEMPERATURES SEVERAL DEGREES ABOVE NORMAL (LOWER 90S INLAND...UPPER 80S IMMEDIATE COAST) IN PERSISTENT S-SW SURFACE FLOW. PLENTY OF HEAT COMBINED WITH ADDITIONAL HUMIDITY PUMPED UP FROM THE GULF AND ATLANTIC COASTS SHOULD TRIGGER AFTERNOON THUNDERSTORMS THAT SHOULD MAINTAIN THEMSELVES OVERNIGHT DUE TO THE PRESENCE OF THETA-E RIDGING. FRIDAY WILL BE AN INTERESTING DAY AS A MORE SUBSTANTIAL SURFACE LOW PRESSURE SYSTEM APPROACHES THE REGION FROM THE TN/OH VALLEYS. ANOTHER ROUND OF HOT TEMPERATURES (SIMILAR TO THURSDAY) AND PLENTY OF HUMIDITY WILL ONCE AGAIN ACT TO DESTABILIZE THE LOWER LEVELS OF THE ATMOSPHERE AND COULD LEAD TO ADDITIONAL STORM DEVELOPMENT FRIDAY AFTERNOON. SHEAR PROFILE IS MOSTLY UNIDIRECTIONAL WITH SOME LOW LEVEL VEERING WITH HEIGHT...THEREFORE A FEW STORMS COULD BECOME SEVERE WITH LOCALLY DAMAGING WINDS. A FEW CAVEATS TO CONSIDER ARE THE PRESENCE OF LINGERING SHOWER ACTIVITY (ESPECIALLY NEAR THE COAST) FRIDAY MORNING AND HOW MUCH CLOUD COVER WILL STREAM IN AHEAD OF THE LOW AND ITS ASSOCIATED COLD FRONT...BOTH OF WHICH COULD HAMPER CONVECTIVE DEVELOPMENT. TIMING WILL BE EVERYTHING AND WILL CONTINUE TO MONITOR THIS WX SITUATION CLOSELY. SPC HAS THE MID ATLANTIC REGION WITHIN A SLIGHT RISK AREA FOR FRIDAY. WILL KEEP THREAT FOR STRONG TO SEVERE STORMS OUT OF THE HAZARDOUS WEATHER OUTLOOK FOR NOW. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... UPR-LVL TROF PIVOTS FROM THE OH VALLEY TO THE NORTHEAST FRI NGT INTO SAT...LEADING TO THE RAIN FRI CONTINUING INTO FRI NGT AND SAT. SFC LO PRES AND AN ASSOCIATED COLD FRNT...DEEP MOISTURE...A PRE-FRONTAL TROF...AND RFQ OF AN UPR-LVL JET STREAK WILL LEAD TO SHWRS AND TSTMS LIKELY FRI NGT (60% POPS)...WITH 50% POPS FOR SAT AS MODELS HAVE SLOWED THE PROGRESSION OF THE AFOREMENTIONED TROF AND ASSOCIATED COLD FRNT. STRONG STORMS ARE POSSIBLE AS WELL DUE TO STRONG FORCING... SHEAR...AND A DEVELOPING LLJ. FROPA MAY BE DELAYED UNTIL SAT AFTN/EVENG...WITH POPS DECREASING SAT NGT AND SUN. HI PRES BLDS IN BEHIND THE FRNT ERLY NEXT WEEK WITH POPS CAPPED AT 20-30%. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS IN THE MID TO UPR 80S WITH LOWS IN THE MID 60S TO LOW 70S. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... AS OF 18Z...SCATTERED SHOWERS WERE SPREAD OUT ACROSS EASTERN PORTIONS OF THE AREA. THE TAF SITES HAVE HAD FREQUENT PERIODS OF MVFR THROUGHOUT THE PAST SIX HOURS. HAVE VFR WITH TEMPO GROUP OF MVFR NEXT FEW HOURS. TSTMS ARE EXPECTED TO INCREASE THROUGH THE AFTN WITH SOME POSSIBLY DEVELOPING OVER THE PIEDMONT. ALL THE TAF SITES EXCEPT SBY HAVE A 2 HOUR PREDOMINANT PERIOD OF SHOWERS WITH TSTMS IN VICINITY FOR LATE AFTN/EARLY EVENING. WILL UPDATE IF TSTMS BECOME MORE CERTAIN FOR THE TERMINAL AREA. MOS FCSTS ARE MORE BULLISH ON IFR WEDNESDAY MORNING COMPARED WITH WHAT THEY HAD 24 HOURS AGO FOR THIS MORNING. IFR WILL BE INFLUENCED ON HOW MUCH CLEARING OCCURS OVERNIGHT AND HOW MUCH RAIN FALLS THIS EVENING. HAVE PLENTY OF MVFR IN THE TAFS BUT HELD BACK ON IFR FOR NOW. UPDATES CAN REASSESS THE SITUATION. CONDITIONS WILL LIKELY BE SLOW TO IMPROVE WEDNESDAY MORNING WITH LIGHT WINDS IN PLACE. KEPT MVFR GOING THROUGH 18Z EXCEPT AT SBY. OUTLOOK...NO APPRECIABLE CHANGE IN THE WX PATTERN IS EXPECTED FOR THE NEXT SEVERAL DAYS. CHC FOR TSTMS WEDNESDAY AFTN WILL BE HIGHEST OVER ORF/ECG...WITH ANOTHER CHANCE FOR TSTMS AGAIN ON THURSDAY AFTERNOON. SHOWER AND THUNDERSTORM CHANCES INCREASE ACROSS THE AREA FOR FRIDAY AND SATURDAY AS A MORE SUBSTANTIAL LOW PRESSURE SYSTEM IMPACTS THE MID ATLANTIC REGION. && .MARINE... NO MARINE HEADLINES NEC FOR THE NEXT FEW DAYS. WEAK FRNTAL BNDRY CURRENTLY STALLED OVER NORTHERN PORTIONS OF THE AREA WILL REMAIN FAIRLY STATIONARY AND SLOWLY DISSIPATE THRU WED. WEAK PRES GRADIENT ASSOCIATED WITH THE FRNT CONTINUES SO WINDS MAINLY S/SW AOB 10 KT... UP TO AROUND 15 KT AT TIMES. WAVES 1-2 FT AND SEAS 2-3 FT. S/SW WINDS SLOWLY INCREASE THU-FRI-SAT AHEAD OF THE NEXT (STRONGER) COLD FRNT WITH MARGINAL SCA CONDITIONS POSSIBLE. SEAS WILL BUILD FROM 3-4 FT FRI NGT TO 4-6 FT SAT. THE FROPA OCCURS LATE SAT/SAT NGT. QUIET MARINE CONDITIONS RETURN SUN THRU TUE AS SFC HI PRES BLDS IN FROM THE WEST BEHIND THE FRNT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...BMD NEAR TERM...BMD SHORT TERM...BMD LONG TERM...MAS AVIATION...LSA/BMD MARINE...MAS ______________________________________________________________________ --- Site: KALY --- --- Site: KAMA --- --- Site: KAPX --- --- Site: KARX --- --- Site: KBGM --- --- Site: KBIS --- --- Site: KBMX --- --- Site: KBOI --- --- Site: KBOU --- --- Site: KBOX --- --- Site: KBRO --- --- Site: KBTV --- --- Site: KBUF --- --- Site: KBYZ --- --- Site: KCAE --- --- Site: KCAR --- --- Site: KCHS --- KCHS - Reference: ['kclx radar data as well as 1km modis satellite imagery show'] 605 FXUS62 KCHS 302151 AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 451 PM EST MON JAN 30 2012 ...FIRES PRODUCING SMOKEY CONDITIONS FOR SOME AREAS... .SYNOPSIS... HIGH PRESSURE ACROSS THE AREA TONIGHT WILL SHIFT INTO THE ATLANTIC THROUGH WEDNESDAY...BEFORE A COLD FRONT MOVES THROUGH THE REGION LATE THURSDAY. HIGH PRESSURE WILL THEN BUILD FROM THE NORTH...WITH A COMPLEX STORM SYSTEM POSSIBLY IMPACTING THE AREA LATER IN THE WEEK INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... KCLX RADAR DATA AS WELL AS 1KM MODIS SATELLITE IMAGERY SHOW NUMEROUS FIRES HAVE BROKEN OUT ACROSS SOUTHERN SOUTH CAROLINA AND EASTERN GEORGIA THIS AFTERNOON WITHIN THE LOW HUMIDITY REGIME. THE FIRES ARE PRODUCING SMOKEY CONDITIONS WITH VSBYS AS LOW AS 3-5 MILES AT TIMES. THE MOST CONCENTRATED AREAS OF FIRES ARE GENERALLY CONFINED WEST OF INTERSTATE 95 SO HAVE UPDATED OUR TEXT AND GRIDDED FORECASTS TO HIGHLIGHT AREAS OF SMOKE IN THIS REGION THROUGH EARLY EVENING. A SPECIAL WEATHER STATEMENT HAS ALSO BEEN ISSUED TO ADDRESS THE AIR QUALITY ASPECT OF THE FIRES AS EPA GUIDANCE INDICATES VSBYS OF 3-5 MILES ARE UNHEALTHY FOR SENSITIVE GROUPS. THE CENTER OF SURFACE HIGH PRESSURE WILL STEADILY SHIFT OFF THE SOUTHEAST COASTLINE THROUGH TONIGHT...WITH NEARLY ZONAL FLOW PREVAILING ALOFT. WEAK SHORTWAVE ENERGY WILL APPROACH THE AREA FROM THE GULF COAST STATES AFTER MIDNIGHT...RESULTING IN JUST A FEW TO SCATTERED CIRRUS NEAR DAYBREAK. THUS...UNDER A WEAK PRESSURE GRADIENT AND MOSTLY CLEAR SKIES...EXPECT IDEAL CONDITIONS FOR RADIATIONAL COOLING TONIGHT. TEMPERATURES WILL FALL INTO THE 30S FOR MOST AREAS AWAY FROM THE IMMEDIATE COAST. LOCATIONS NEAR THE COASTLINE WILL LIKELY BE MODERATED AROUND 40 DEGREES DUE TO ONSHORE FLOW. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... TUESDAY THROUGH WEDNESDAY...SURFACE HIGH PRESSURE WILL MOVE OFFSHORE WITH FAIRLY ZONAL FLOW ALOFT CONTINUING. THIS WILL MAKE FOR A WARMING TREND WITH TEMPERATURES RISING WELL ABOVE NORMAL PAST 70 FOR MOST LOCALES AWAY FROM THE IMMEDIATE COAST...ESPECIALLY BY WEDNESDAY. MOISTURE WILL BE ON THE INCREASE FROM THE WEST BY LATER WEDNESDAY BUT KEPT IT RAIN-FREE FOR NOW. COULD SEE SOME PATCHY FOG WEDNESDAY MORNING. WEDNESDAY NIGHT AND THURSDAY...RAIN CHANCES INCREASE AS DEEPER MOISTURE OVERSPREADS THE AREA ALONG WITH AN UPPER SHORTWAVE AND A COLD FRONT APPROACHES FROM THE WEST AND POSSIBLY EVEN PUSHES THROUGH. HIGHS WILL BE KNOCKED BACK A FEW DEGREES THURSDAY BUT LIKELY NOT MUCH DUE TO THE DOWNSLOPE FLOW BEHIND THE FRONT. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A VERY COMPLEX PATTERN WILL UNFOLD DURING THE LATE WEEK INTO EARLY NEXT WEEK...BUT WE DO SEE SOME CHANCES FOR RAINFALL. IN WAKE OF THE COLD FRONT...HIGH PRESSURE BUILDS FROM THE NORTH FRIDAY...AND DEVELOPS INTO A HIGH PRESSURE WEDGE INTO SATURDAY. A COASTAL TROUGH WILL EVENTUALLY FORM DURING THIS TIME...WHILE A FRONTAL SYSTEM TAKES SHAPE OVER THE CENTRAL STATES. AS THAT SYSTEM MOVES EAST AND WE REMAIN CLOSE PROXIMITY TO THE COASTAL TROUGH...WE/LL SEE OUR RAIN CHANCES CLIMB FROM LATER FRIDAY INTO SATURDAY. SINCE THERE IS TOO MUCH UNCERTAINTY AS TO HOW THIS WILL ACTUALLY EVOLVE...WE ARE HESITANT TO GO ANY HIGHER THAN SLIGHT CHANCE POPS FRIDAY...AND CHANCE POPS SATURDAY. TEMPS WILL REMAIN ABOVE SEASONAL LEVELS...BUT IF THE WEDGE DOES INDEED FORM...TEMPS SATURDAY MIGHT BE SIGNIFICANTLY COOLER THAN NOW IN THE FORECAST AND/OR THERE COULD BE A MUCH LARGER RANGE THAN WE CAN DEPICT SEVERAL DAYS IN ADVANCE. ALTHOUGH THERE IS SOME UNCERTAINTY AS TO EXACTLY WHEN THE COLD FRONT ASSOCIATED WITH THE SYSTEM TO OUR WEST AND NW MOVES THROUGH...AT PRESENT IT LOOKS TO BE SUNDAY...BEFORE HIGH PRESSURE RETURNS BY MONDAY. IF THIS SCENARIO HOLDS TRUE...THEN RAIN CHANCES WILL DROP OUT OF THE FORECAST EARLY NEXT WEEK. THIS FORECAST SCENARIO IS A LOW CONFIDENCE FORECAST...BUT WE DO HIGHER CONFIDENCE THOUGH ON TEMPS...WHICH WILL REMAIN ABOVE NORMAL. && .AVIATION /22Z MONDAY THROUGH SATURDAY/... VFR CONDITIONS WILL PREVAIL THROUGH 18Z TUESDAY...WITH ONLY A SMALL CHANCE FOR SHALLOW GROUND FOG AROUND DAYBREAK TUESDAY MORNING. EXTENDED AVIATION OUTLOOK...EXCEPT FOR A LOW CHANCE FOR GROUND FOG LATE TUESDAY NIGHT/EARLY WEDNESDAY...VFR CONDITIONS WILL PREVAIL THROUGH WEDNESDAY. MVFR OR LOWER POSSIBLE FOR WEDNESDAY NIGHT AND/OR THURSDAY. GENERALLY VFR CONDITIONS WILL RETURN FOR LATE THURSDAY INTO FRIDAY. && .MARINE... QUIET CONDITIONS WILL CONTINUE FOR THE COASTAL WATERS THROUGH AT LEAST TONIGHT...AS SURFACE HIGH PRESSURE STEADILY SHIFTS OFF THE SOUTHEAST COASTLINE. EAST TO SOUTHEAST FLOW LESS THAN 10 KT IS EXPECTED...WITH SEAS GENERALLY DOWN TO 1 TO 2 FT. TUESDAY THROUGH SATURDAY...CONDITIONS ACROSS THE MARINE COMMUNITY WILL REMAIN FAIRLY QUIET THROUGH MID WEEK...WITH ATLANTIC HIGH PRESSURE TO EXTEND ACROSS THE AREA. A COLD FRONT WILL MOVE THROUGH LATE THURSDAY...WITH HIGH PRESSURE TO BUILD IN ITS WAKE FROM THE NORTH FRIDAY. WINDS/SEAS LOOK TO INCREASE IN THIS PATTERN LATE IN THE WEEK...ESPECIALLY IF A COASTAL TROUGH OF LOW PRESSURE DEVELOPS OVER/NEAR THE WATERS. THUS...SMALL CRAFT ADVISORIES MAY BE NEEDED DURING THIS PERIOD. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ ______________________________________________________________________ KCHS - Reference: ['moves back toward the coast...and the latest modis sst images show '] 156 FXUS62 KCHS 240812 AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 412 AM EDT THU MAY 24 2012 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL GRADUALLY BUILD NORTH AND WEST OF THE AREA THROUGH SATURDAY...WHILE AN AREA OF LOW PRESSURE DEVELOPS ALONG AN INVERTED TROF OVER THE SOUTHWESTERN ATLANTIC AND BAHAMAS. BY SUNDAY...THE ATLANTIC LOW WILL BEGIN TO RETROGRADE TO THE SOUTHWEST TOWARD FLORIDA AS THE HIGH PRESSURE RIDGE REMAINS IN PLACE. THE LOW WILL MOVE INTO THE NORTHEASTERN GULF OF MEXICO EARLY NEXT WEEK...WHILE THE HIGH NEAR THE AREA GRADUALLY WEAKENS BY TUESDAY. && .NEAR TERM /THROUGH TONIGHT/...THE AREA WILL BE BETWEEN WEAK UPPER TROUGHING TO THE WEST AND AN UPPER LEVEL RIDGE WELL TOT HE SOUTHEAST OF THE AREA. SURFACE LOW PRESSURE IS EXPECTED TO FORM DURING THIS PERIOD NEAR OR JUST NORTH OF A BAHAMAS. AFTER SOME PATCHY EARLY MORNING FOG...PLENTY OF SUNSHINE EXPECTED TODAY WILL ALLOW TEMPERATURES TO CLIMB TO VALUES NEAR OR SLIGHTLY ABOVE YESTERDAYS VALUES...MAINLY FROM THE MID 80S TO NEAR 90. WITH WEAK LOW LEVEL FLOW...EXPECT THE SEA BREEZE TO MAKE GOOD PROGRESS INLAND THIS AFTERNOON. CONVERGENCE IS EXPECTED TO BE FAIRLY WEAK ALONG THE SEA BREEZE BUT WITH LIFTED INDICES PROGGED BY VARIOUS MODELS FROM -3 TO -5 AND CAPE VALUES FROM 1000 TO 1500 J/KG...CANNOT RULE OUT A FEW SHOWERS OR THUNDERSTORMS ALONG THE SEA BREEZE...ESPECIALLY ACROSS THE SOUTH CAROLINA ZONES. THE HRRR AND OTHER HIGH RESOLUTION MODELS SHOW THIS OCCURRING WHILE BOTH THE 00Z/24 NAM AND GFS KEEP THINGS DRY. MAINTAINED SLIGHT CHANCE FOR AFTERNOON POPS ALONG AND WEST OF THE SEAS BREEZE IN MOST AREAS. ANY EVENING CONVECTION SHOULD QUICKLY DISSIPATE WITH THE LOSS OF HEATING. SKIES SHOULD MAINLY BE CLEAR OVERNIGHT WHICH MAY ALLOW FOR SOME AREAS OF FOG TO FORM. FOR THE TIME BEING HAVE NOT INCLUDED ANY FOG IN THE FORECAST...BUT THIS MAY NEED TO ADDED BY LATER SHIFTS...ESPECIALLY FOR AREAS THAT GET RAIN TODAY. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... FRIDAY THROUGH SATURDAY...A DEEP LAYERED RIDGE WILL BUILD TO THE NORTH AND WEST OF THE AREA...WHILE AN AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP WELL OFFSHORE IN THE WESTERN ATLANTIC. THE BUILDING HEIGHTS WILL CAUSE SOME WARMING...DRYING AND SUBSIDENCE AT MID LEVELS...SUPPRESSING CONVECTIVE DEVELOPMENT IN THE AFTERNOON HOURS DESPITE SOME DECENT LOW LEVEL INSTABILITY WITH TEMPS INTO THE LOW 90S INLAND. THE CHANCE OF RAIN WILL BE BELOW 20 PERCENT EACH DAY. THE FORECAST GETS MUCH TRICKIER ON SATURDAY AS THE MODELS GIVE A VARIETY OF SOLUTIONS ON HOW THE LOW OVER THE WESTERN ATLANTIC WILL EVOLVE. THEY ALL RETROGRADE THE LOW BACK TOWARD THE COAST AS THE UPPER RIDGE BUILDS OFF THE MID ATLANTIC COAST...TRAPPING THE LOW AND PREVENTING IT FROM MOVING NORTH AND EASTWARD OUT TO SEA. AT THIS TIME...I PREFER A GFS SOLUTION BRINGING THE SYSTEM TOWARD THE NORTH FLORIDA COAST BY LATE SUNDAY. THAT WOULD PUT US ON THE PERIPHERY OF THE SYSTEM WITH SOME GUSTY WINDS AT TIMES ON SUNDAY... AS WELL AS AN INCREASED CHANCE FOR RAIN. THE STRONGER ONSHORE WINDS AND MORE CLOUDS WOULD ALSO MEAN LOWER TEMPS SUNDAY AFTERNOON...SO I ADJUSTED ACCORDINGLY. MY MAIN REASONING FOR PREFERRING THE GFS IS THE LACK OF ORGANIZATION CURRENTLY SHOWN ON THE SATELLITE IMAGERY. FOR THE NAM SOLUTION TO WORK OUT...THERE WOULD ALREADY HAVE TO BE A DISTINCT SURFACE LOW NORTH OF THE BAHAMAS BY THIS AFTERNOON...AND I DO NOT SEE THAT HAPPENING RIGHT NOW. ALSO...THE LATEST ECMWF IS JUST COMING IN...AND SO FAR IT LOOKS MORE LIKE THE GFS THAN THE NAM. THE OTHER FORECAST PROBLEM IS THE NATURE OF THE SYSTEM. PHASE SPACE DIAGRAMS INDICATE THAT THE SYSTEM MAY WELL DEVELOP A WARM CORE AS IT MOVES BACK TOWARD THE COAST...AND THE LATEST MODIS SST IMAGES SHOW WATER TEMPS IN THE EXPECTED PATH AROUND 80F...SO IT IS POSSIBLE THE SYSTEM COULD DEVELOP TROPICAL CHARACTERISTICS. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... FOLLOWING THROUGH WITH THE DISCUSSION ABOVE...THE GFS CONTINUES TO BRING THE LOW ACROSS NORTHERN FLORIDA AND INTO THE NORTHEASTERN GULF OF MEXICO EARLY NEXT WEEK. THIS WILL CAUSE OUR WINDS TO SWITCH AROUND TO THE SOUTHEAST AND SOUTH...BRINGING SOME DEEPER MOISTURE BACK INTO THE CWA AND GIVING US A MORE TYPICAL THREAT FOR DIURNAL CONVECTION. OF COURSE...THERE IS A FAIR AMOUNT OF UNCERTAINTY HERE AS THE EVENTUAL EVOLUTION OF THE ATLANTIC LOW WILL PLAY A MAJOR FACTOR IN THE SENSIBLE WEATHER DURING THIS TIME PERIOD. IT POSSIBLE THE LOW COULD STALL OVER NORTHERN FLORIDA...THEN WAIT FOR THE RIDGE TO BREAK DOWN AND START MOVING NORTHWARD OR NORTHEASTWARD...AS THE ECMWF SUGGESTS. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... VFR LIKELY AT KCHS AND KSAV THROUGH THURSDAY. LOOKS LIKE A DECENT CHANCE FOR SOME LIGHT FOG AT BOTH TERMINALS SO HAVE INTRODUCED A TEMPO GROUP FOR 5SM BR FROM 08Z TO 12Z. OUTSIDE CHANCE FOR BRIEF MVFR VISIBILITY IN GROUND FOG AROUND DAYBREAK THURSDAY...BUT FEEL CHANCES ARE TOO LOW TO INCLUDE IN THE TAFS ATTM. ALSO SOME MVFR CIGS OBSERVED AT KGGE AND EARLIER AT KMYR...BUT THINK THAT MVFG CIGS WILL REMAIN CONFINED TO AREAS NORTH OF KCHS. POPS TOO LOW TO JUSTIFY ANY MENTION OF THUNDER THURSDAY AFTERNOON. EXTENDED AVIATION OUTLOOK...THERE IS A CHANCE FOR A LITTLE MVFR VSBYS/CIGS FRIDAY MORNING...BUT OTHERWISE VFR THROUGH SATURDAY. CONDITIONS MAY DETERIORATE A LITTLE SUNDAY AND MONDAY DEPENDING ON WHAT HAPPENS WITH THE ATLANTIC LOW THAT IS EXPECTED TO DEVELOP AND MOVE SOUTHWESTWARD. WINDS WILL GET A BIT GUSTIER...AND THERE WILL BE A BETTER CHANCE FOR MVFR/IFR VSBYS/CIGS IN CONVECTION. && .MARINE... TRANQUIL MARINE CONDITIONS EXPECTED TODAY AND TONIGHT WITH WINDS AOB 15 KNOTS AND SEAS AOB 4 FEET. NORTHEASTERLY WINDS WILL RULE THE COASTAL WATERS FRIDAY AND SATURDAY AS THE REGION WILL SIT BETWEEN HIGH PRESSURE TO THE NORTHWEST AND A DEVELOPING AREA OF LOW PRESSURE NORTH OF THE BAHAMAS. WINDS WILL BE GENERALLY 15 KNOTS OR LESS IN THE NEAR SHORE WATERS...WITH 15 TO 20 KNOTS IN THE OFFSHORE GEORGIA WATERS BY SATURDAY. BASED ON THE CURRENT BELIEF THAT THE LOW WILL DEVELOP AND MOVE SOUTHWESTWARD TOWARD THE NORTHERN FLORIDA COAST ON SUNDAY...WINDS AND SEAS WILL INCREASE...AND ADVISORIES WILL LIKELY BE NEEDED BY SATURDAY NIGHT OR SUNDAY MORNING IN THE WATERS. THE WINDS AND SEAS WILL STAY UP SUNDAY NIGHT BEFORE COMING DOWN DURING THE DAY MONDAY AS THE LOW IS EXPECTED TO MOVE ACROSS NORTH FLORIDA AND EVENTUALLY INTO THE NORTHEASTERN GULF OF MEXICO. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ SYNOPSIS... NEAR TERM...MTE SHORT TERM...ALSHEIMER LONG TERM...ALSHEIMER AVIATION...SPR/MTE MARINE...ALSHEIMER/MTE ______________________________________________________________________ KCHS - Reference: ['with modis tpw products showing pwats in the 2 inch range as far'] 403 FXUS62 KCHS 280718 AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 318 AM EDT MON MAY 28 2012 ...PRELIMINARY AREA FORECAST DISCUSSION... .SYNOPSIS... TROPICAL STORM BERYL MADE LANDFALL IN NORTHEAST FLORIDA EARLY THIS MORNING. THE SYSTEM IS EXPECTED TO STALL ACROSS SOUTHERN GEORGIA AND NORTHERN FLORIDA BEFORE MOVING BACK UP THE SOUTHEAST COAST THROUGH THE MIDDLE OF THE WEEK. A COLD FRONT APPROACHING FROM THE WEST COULD IMPACT THE AREA FOR THE LATE WEEK PERIOD...WITH HIGH PRESSURE FOLLOWING IN ITS WAKE THROUGH EARLY NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... TROPICAL STORM BERYL MADE LANDFALL NEAR JACKSONVILLE BEACH FLORIDA AT 1210 AM WITH MAXIMUM SUSTAINED WINDS NEAR 70 MPH. THE CENTER OF CIRCULATION HAS CONTINUED TO MOVE WEST AND REMAINS WELL DEFINED PER SATELLITE AND KJAX REFLECTIVITY DATA. NUMEROUS FEEDER BANDS ARE STILL WRAPPING AROUND ITS BROAD CYCLONIC CIRCULATION WITH MODERATE TO OCCASIONALLY HEAVY RAINFALL STREAMING INLAND FROM OFF THE ATLANTIC ACROSS MAINLY SOUTHEAST GEORGIA AND FAR SOUTHERN SOUTH CAROLINA. THE PRIMARY FORECAST CONCERNS TODAY CENTER ON THE CONTINUED RISK FOR LINGERING LOW-END TROPICAL STORM CONDITIONS ACROSS NORTH COASTAL GEORGIA AND THE PLACEMENT/EXTENT OF RAINFALL THROUGH THE DAY. WITH BERYL NOW INLAND...STEADILY WEAKENING WILL ENSUE. MARINE OBSERVATIONS OFF THE COAST ALREADY INDICATE A DOWNWARD TREND IN WINDS IS OCCURRING AND WOULD EXPECT THE RISK FOR TROPICAL STORM FORCE WINDS...MAINLY IN GUSTS...TO BE CONFINED TO THE NORTH GEORGIA ZONES THROUGH MID-MORNING AT THE LATEST. THE RISK FOR TROPICAL STORM CONDITIONS HAS GENERALLY ENDED FOR JASPER-BEAUFORT AND COLLETON COUNTIES WITH THE EXCEPTION OF SOME LOCALLY ENHANCED WIND GUSTS POSSIBLY OCCURRING WITHIN TRANSIENT SHOWER ACTIVITY... SO WILL COORDINATE WITH NHC SHORTLY TO POSSIBLY CANCEL THE TROPICAL STORM WARNING FOR THOSE AREAS WITH THE NEXT ADVISORY. ANTICIPATE ALL TROPICAL STORM WARNINGS WILL BE DISCONTINUED BY THIS AFTERNOON IF NOT LATER THIS MORNING AS BERYL MOVES FARTHER INLAND AND WEAKENS. THE AXIS OF HIGHEST PWATS WILL REMAIN ANCHORED ACROSS SOUTHEAST GEORGIA THROUGH THIS AFTERNOON AS BERYL BEGINS TO STALL ACROSS SOUTHERN GEORGIA/NORTHERN FLORIDA. CORRESPONDINGLY...THE HIGHEST COVERAGE OF SHOWERS WILL GENERALLY REMAIN IN THIS AREA. HOWEVER... WITH MODIS TPW PRODUCTS SHOWING PWATS IN THE 2 INCH RANGE AS FAR NORTH AS THE SOUTHERN MIDLANDS THE RISK FOR AT LEAST SCATTERED ACTIVITY WILL OCCUR EVEN ACROSS THE CHARLESTON TRI-COUNTY AREA. POPS WILL RANGE FROM 80 PERCENT ACROSS THE COUNTIES BORDERING THE ALTAMAHA RIVER TO 40 PERCENT ACROSS THE CHARLESTON TRI-COUNTY AREA. HIGHS WILL BE IN THE MID 80S WITH LOWER 80S CLOSER TO THE BEACHES. && .SHORT TERM /TONIGHT THROUGH THURSDAY/... TO BE ISSUED. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... TO BE ISSUED. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... KCHS...IT IS LIKELY THAT MOISTURE/SPEED CONVERGENCE OVERNIGHT WILL BE ENOUGH TO GENERATE LOWER CIGS AND WE HAVE MAINTAINED MVFR CIGS OVERNIGHT. ON MON...AWAY FROM THE MAIN PCPN SHIELD OF THE TROPICAL SYSTEM...A DEEP MOIST PROFILE WILL MAINTAIN SCATTERED TO BROKEN CUMULUS AND A RISK OF SHOWERS DURING THE DAY INTO THIS EVENING WITH SOME DIURNAL ENHANCEMENTS TO WIND SPEEDS...HOWEVER GUSTS A GOOD BIT BELOW SUNDAY/S SPEEDS. KSAV...AN INITIAL BAND OF RAINS ASSOCIATED WITH BERYL PRODUCED GUSTS TO NEAR 40 MPH BRIEFLY AND ADDITIONAL SHOWERS MAY PRODUCE GUSTS NEAR 30 KT OVERNIGHT. OTHERWISE...OCCASIONAL MVFR CIGS ON TAP THROUGH THE TAF CYCLE AS MOISTURE REMAINS DEEP AND SHOWER RISKS CONTINUE. THE GREATEST CHANCES FOR RAINS WILL BE CLOSER TO BERYL NEAR THE SWAMPS OF SOUTH GEORGIA. PREVAILING RAINS AFTER LATE MORNING HAVE BEEN KEPT OUT OF PICTURE UNTIL RADAR TRENDS DICTATE LATER. EXTENDED AVIATION OUTLOOK...SUB-VFR CONDITIONS REMAIN LIKELY THROUGH TUESDAY AS TS BERYL OR REMNANTS IMPACT THE REGION. GUSTY CONDITIONS ALSO POSSIBLE AT TIMES...MAINLY DURING THE AFTERNOON. && .MARINE... CANCELLED THE TROPICAL STORM WARNING FOR THE CHARLESTON COUNTY COASTAL WATERS AND ISSUED A SMALL CRAFT ADVISORY THROUGH THIS AFTERNOON. RIP CURRENTS...A PERSISTENT ONSHORE FETCH AND LINGERING LARGE SURF/SWELL WILL YIELD A HIGH RISK FOR RIP CURRENTS AT AREA BEACHES TODAY. && .HYDROLOGY... TO BE ISSUED. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...TROPICAL STORM WARNING FOR GAZ116>119-137>141. FLASH FLOOD WATCH THROUGH TUESDAY AFTERNOON FOR GAZ114>119- 137>141. SC...TROPICAL STORM WARNING FOR SCZ047>049-051. MARINE...TROPICAL STORM WARNING FOR AMZ352-354-374. SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ350. SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR AMZ330. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE... HYDROLOGY... ______________________________________________________________________ KCHS - Reference: ['fact...high resolution modis water temperature data indicate the'] 121 FXUS62 KCHS 282011 AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 311 PM EST FRI DEC 28 2012 ...MORE BENEFICIAL RAINS TO FALL LATE TONIGHT AND EARLY SATURDAY... .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT...PUSH OFFSHORE SATURDAY MORNING AND BE FOLLOWED BY HIGH PRESSURE THROUGH MONDAY ANOTHER COLD FRONT WILL DROP INTO THE REGION ON TUESDAY WITH SEVERAL WAVES OF LOW PRESSURE MOVING UP THE COAST ALONG THE FRONT THROUGH THURSDAY. HIGH PRESSURE WILL REBUILD LATE NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... OVERVIEW...MID-AFTERNOON WATER VAPOR IMAGERY SHOWS A WELL-DEFINED BAROCLINIC LEAF EXPANDING OVER THE SOUTHERN MISSISSIPPI VALLEY AHEAD OF UPPER LEVEL LOW PRESSURE MOVING ACROSS THE TEXAS PANHANDLE. AT THE SURFACE...1006MB LOW PRESSURE WAS SLOWLY DEEPENING OVER CENTRAL LOUISIANA UNDERNEATH THE SAID BAROCLINIC LEAF. MODELS SHOW THE SURFACE LOW MOVING RAPIDLY NORTHEAST INTO THE SOUTHERN OHIO VALLEY OVERNIGHT WITH SECONDARY CYCLOGENESIS TAKING PLACE ALONG THE CAROLINA COAST--MORE TYPICAL OF A CLASSIC MILLER TYPE-B SYNOPTIC PATTERN. MARINE OBSERVATIONS OVER THE COASTAL WATERS SHOW A COASTAL TROUGH BECOMING BETTER DEFINED ALONG THE WESTERN WALL OF THE GULF STREAM THIS AFTERNOON. A WARM FRONT FORMING ALONG THE GULF COAST IS FORECAST TO LINK UP WITH THE COASTAL TROUGH LATER THIS EVENING AND GRADUALLY SHIFT NORTH ACROSS THE FORECAST AREA OVERNIGHT. THE MAIN FORECAST CONCERNS FOR TONIGHT CENTER AROUND RAIN CHANCES AND PINNING DOWN LOW TEMPERATURES. RAIN CHANCES...IT LOOKS TO BE A WET LATE NIGHT FOR MUCH OF SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA. UPPER LEVEL DYNAMICS WILL STEADILY INCREASE AS THE UPPER LOW OVER THE TEXAS PANHANDLE OPENS UP AND EJECTS OUT ACROSS THE TENNESSEE VALLEY INTO THE CENTRAL APPALACHIANS BY SUNRISE SATURDAY. DEEP LAYERED OMEGA WITHIN A VERY MOIST COLUMN FEATURING PWATS IN EXCESS OF 1.5 INCHES WILL SUPPORT WIDESPREAD RAINS MODERATE TO PERHAPS HEAVY RAINS SETTING UP WITHIN A CORRIDOR FROM THE CSRA AND SOUTHERN MIDLANDS INTO THE NORTHERN PORTIONS OF THE FORECAST AREA COINCIDENT WITH A RIBBON OF STRONG FRONTOGENETIC FORCING. ALTHOUGH THE STRONGEST FORCING LOOKS TO SETUP ACROSS THE NORTHERN ZONES...QUITE A BIT OF RAIN WILL STILL FALL OVER THE CENTRAL AND SOUTHERN PORTIONS PRIOR TO SUNRISE...ALTHOUGH LIKELY NOT AS HEAVY. IT DOES APPEAR MUCH OF THE EVENING HOURS WILL REMAIN DRY WITH THE SURGE OF STRONGEST LOW- LEVEL MOISTURE TRANSPORT NOT ARRIVING UNTIL AFTER THE WARM FRONT PUSHES THROUGH. WILL SHOW POPS ONLY 20-30 PERCENT THROUGH SUNRISE...INCREASING RAPIDLY TO 80-100 PERCENT AFTER 2-3 AM...HIGHEST OVER THE NORTHERN HALF OF THE FORECAST AREA. THUNDERSTORMS...THERE WILL BE A RISK FOR ISOLATED...EMBEDDED THUNDERSTORMS LATE TONIGHT AND EARLY SATURDAY AS RAIN OVERSPREADS THE REGION FROM THE WEST. ALTHOUGH SURFACE BASED INSTABILITY WILL BE LACKING...NAM/GFS AND ECWMF ALL SHOW SHOWALTER VALUES GOING NEGATIVE AS MID-LEVEL TEMPERATURES COOL. THIS SHOULD SUPPORT AT LEAST A FEW EMBEDDED THUNDERSTORMS...ESPECIALLY WHERE FRONTOGENETIC FORCING IS THE GREATEST. WILL INTRODUCE A SLIGHT CHANCE FOR THUNDERSTORMS FROM ROUGHLY MIDNIGHT ON. GIVEN THE ELEVATED WIND FIELDS ALOFT...ANY THUNDERSTORMS OR POCKETS OF HEAVY RAIN THAT DO FORM COULD BRING SOME BRIEF/GUSTY WINDS NEAR 40 MPH. TEMPERATURES...PINNING DOWN LOW TEMPERATURES AS WELL AS HOURLY TEMPERATURES WILL BE EXTREMELY DIFFICULT TONIGHT. SATELLITE SHOWS SOME CLEARING TAKING PLACE OVER CENTRAL GEORGIA LATE THIS AFTERNOON. ALTHOUGH SOME CIRRUS WILL LIKELY LINGER...COULD SEE TEMPERATURES DROP FAIRLY QUICKLY THIS EVENING AS WINDS DROP OFF. HOWEVER...TEMPERATURES ARE THEN EXPECTED TO STEADY OUT AND EVEN RISE BY LATE EVENING AS CLOUDS THICKEN AND THE DEVELOPING WARM FRONT SHIFTS TO THE NORTH. LOWS LOOKS TO BOTTOM OUT IN THE MID- UPPER 40S INLAND WITH LOWER-MID 50S COAST. COMPLICATING MATTERS IS THAT AFTER RISING OVERNIGHT...TEMPERATURES WILL THEN LIKELY FALL SOME AS RAIN BEGINS TO FALL. HAVE TRIED TO ACCOUNT FOR ALL OF THIS IN THE HOURLY TEMPERATURE FORECASTS...HOWEVER ADJUSTMENTS--SOME POSSIBLY SIGNIFICANT--MAY BE NEEDED LATER THIS EVENING ONCE CLOUDS AND THERMAL TRENDS BECOME MORE APPARENT. && .SHORT TERM /SATURDAY THROUGH MONDAY/... LOW PRESSURE IS EXPECTED TO MOVE NORTHEAST THROUGH THE LOCAL AREA EARLY SATURDAY BEFORE DEEPENING AND TRACKING OFF THE MID ATLANTIC AND NEW ENGLAND COASTLINES. DEEP MOISTURE WILL BE DECREASING QUICKLY BEHIND THE LOW AND ACCUMULATING RAINFALL LOOKS TO BE ENDING BY MID MORNING ACROSS INLAND AREAS AND SHORTLY THEREAFTER NEAR THE COAST. A WARMING DOWNSLOPE FLOW AND DEEPENING MIXED LAYER WILL MEAN BREEZY CONDITIONS FOR THE AFTERNOON WITH GUSTS AROUND 30 MPH. IT WILL BE CLEAR...BRISK AND CHILLY SATURDAY NIGHT AS A MUCH COLDER AIR MASS MOVES INTO THE AREA. MANY INLAND LOCALES SHOULD HIT THE FREEZING MARK BY DAYBREAK SUNDAY. SUNDAY WILL FEATURE PLENTY OF SUN BUT BELOW NORMAL TEMPERATURES IN THE LOWER TO MID 50S DUE TO THE COLD START AND LINGERING CHILLY AIRMASS. SHOULD BE EVEN COLDER SUNDAY NIGHT AS SURFACE HIGH PRESSURE MOVES OVER THE REGION WITH MANY INLAND LOCALES DROPPING INTO THE UPPER 20S. MONDAY WILL BE MILDER WITH TEMPERATURES GETTING BACK CLOSE TO NORMAL. A WEAK TROUGH OF LOW PRESSURE COULD BRING A FEW SHOWERS TO COASTAL AREAS. LAKE WINDS...WINDS WILL PICK UP ON LAKE MOULTRIE LATE SATURDAY INTO SUNDAY BEHIND A COLD FRONT AND AN ADVISORY MAY EVENTUALLY BE NEEDED. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... THE UPPER PATTERN WILL FAVOR A QUASI-ZONAL FLOW WITH SEVERAL PERTURBATIONS RIPPLING THROUGH DURING THE PERIOD. ALTHOUGH MODEL TIMING DIFFERENCES INEVITABLY ABOUND...A COLD FRONT IS EXPECTED TO DROP INTO THE REGION FROM THE NW ON TUESDAY AND DRIFT OFFSHORE BY WEDNESDAY. THEN A SERIES OF WEAK SURFACE WAVES WILL LIFT FROM THE GULF OF MEXICO THROUGH THE SOUTHEAST WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. WE GENERALLY HAVE SOLID CHANCE POPS THROUGHOUT THE PERIOD. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... VFR THROUGH THIS EVENING WITH CONDITIONS DETERIORATING EARLY SATURDAY. WARM FRONT WILL LIFT NORTH THROUGH THE TERMINALS AFTER MIDNIGHT WITH A 40-50 KT LOW-LEVEL JET INITIATING LOW-LEVEL WIND SHEAR /LLWS/ AT BOTH TERMINALS AFTER 08-09Z. THE RISK FOR LLWS WILL LINGER UNTIL FRONTAL PASSAGE ROUGHLY 14-15Z. A WELL DEFINED RAIN BAND WILL ACCOMPANY THE FRONT WITH RAIN REACHING THE TERMINALS AS EARLY AS 09Z. LIMITED CIGS/VSBYS TO MVFR FOR NOW GIVEN THE SPACIAL/TEMPORAL UNKNOWNS THIS FAR OUT...BUT IFR CONDITIONS ARE CERTAINLY A POSSIBILITY. EXPECT RAPID CLEARING TO ENSUE ONCE THE FRONT SHIFTS OFFSHORE AND DOWNSLOPE TRAJECTORIES TAKE HOLD. EXTENDED AVIATION OUTLOOK...LOW-LEVEL WIND SHEAR POSSIBLE SATURDAY NIGHT. INCREASING CHANCES FOR SUB-VFR CONDITIONS LATE TUESDAY AND WEDNESDAY AS A COLD FRONT DROPS SOUTH INTO THE AREA. && .MARINE... TONIGHT...WINDS HAVE BEEN VARIABLE ACROSS MUCH OF THE WATERS TODAY...BUT HAVE RECENTLY BECOME MORE SOLIDLY NORTHEAST ALONG THE CHARLESTON COUNTY COAST AS A WEAK COASTAL TROUGH SHARPENS ALONG THE WESTERN WALL OF THE GULF STREAM. WINDS WILL TURN MORE SOUTHERLY AND RAPIDLY INCREASE OVERNIGHT AS THE COASTAL TROUGH LINKS UP WITH A DEVELOPING WARM FRONT TO THE SOUTH AND PUSHES NORTH THROUGH THE MARINE AREA. ALTHOUGH LOW-LEVEL JETTING BECOMES QUITE IMPRESSIVE WITH 950MB WINDS REACHING 50 KT BY SUNRISE SATURDAY...WATER TEMPERATURES IN THE 50S WILL LIMIT MIXING SIGNIFICANTLY OVER THE NEARSHORE WATERS. THE ONLY EXCEPTION WILL BE OVER THE GEORGIA OFFSHORE WATERS WHERE WARMER WATER TEMPERATURES ARE FOUND. WILL HOIST A SMALL CRAFT ADVISORY FOR THE GEORGIA OFFSHORE LEG BEGINNING SHORTLY AFTER MIDNIGHT. IN FACT...HIGH RESOLUTION MODIS WATER TEMPERATURE DATA INDICATE THE WESTERN WALL OF THE GULF STREAM FEATURING 70+ DEGREE WATER TEMPERATURES IMPINGES IN THE GEORGIA OFFSHORE ZONE TO WITHIN 45-50 NM FROM SHORE. EXPECT SIGNIFICANTLY MORE VIGOROUS MIXING TO OCCUR IN THIS AREA WITH DATA SUPPORTING MARGINAL GALES. GIVEN THESE MORE FAVORABLE MIXING PROFILES WILL ONLY AFFECT ABOUT 10 NM OF THE MUCH LARGER ZONE...WILL LIMIT CONDITIONS TO JUST BELOW GALE FORCE FOR NOW. WILL CALL FOR WINDS 20-25 KT...EXCEPT 25-30 KT BEYOND 40 NM. WW4 OUTPUT LOOKS A BIT HIGH WITH THE GFS BOUNDARY LAYER WINDS NOT TAKING THE POOR MIXING PROFILES INTO ACCOUNT. EXPECT SEAS TO MAX OUT 3-5 FT NEARSHORE WATERS AND 5-7 FT OFFSHORE WATERS. SATURDAY THROUGH WEDNESDAY...LOW PRESSURE IS EXPECTED TO TRACK OVER OR JUST NORTH OF THE WATERS EARLY SATURDAY WITH A TRAILING COLD FRONT TO PUSH THROUGH LATER SATURDAY. CONDITIONS WILL BE POOR THROUGH THIS PERIOD WITH ADVISORY CONDITIONS AT LEAST OVER THE OUTER WATERS BEYOND 20 NM...POSSIBLY REACHING THE EASTERN PORTIONS OF THE NEARSHORE WATERS. WINDS WILL REMAIN ELEVATED/GUSTY SATURDAY NIGHT DUE TO STRONG COLD AIR ADVECTION AND LOW-LEVEL JET. EXPECT SOLID ADVISORY CONDITIONS OFFSHORE WITH EVEN A FEW GALE FORCE GUSTS POSSIBLE. ADVISORIES MAY END UP BEING NEEDED FOR THE NEARSHORE WATERS AS WELL. CONDITIONS TO IMPROVE SUNDAY AS THE PRESSURE GRADIENT RELAXES AND HIGH PRESSURE BUILDS IN FROM THE WEST AND REMAIN RELATIVELY TRANQUIL UNTIL TUESDAY WHEN THE PRESSURE GRADIENT INCREASES AGAIN WITH THE APPROACH OF ANOTHER COLD FRONT FROM THE NORTH. THE FRONT SHOULD PUSH THROUGH WEDNESDAY BUT WE DO NOT ANTICIPATE ANY HEADLINES THROUGH THEN. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 1 AM SATURDAY TO 11 AM EST SUNDAY FOR AMZ374. && $$ ST/RJB ______________________________________________________________________ KCHS - Reference: ['modis sea surface temperature data indicated water temperatures'] 769 FXUS62 KCHS 292321 AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 621 PM EST SAT DEC 29 2012 ...GALE WARNING ISSUED FOR THE GEORGIA OFFSHORE WATERS... .SYNOPSIS... A REINFORCING COLD FRONT WILL MOVE THROUGH THIS EVENING FOLLOWED BY HIGH PRESSURE THROUGH SUNDAY WHICH WILL THEN SHIFT OFFSHORE BY MONDAY. ANOTHER FRONTAL SYSTEM WILL DROP INTO THE SOUTHEAST UNITED STATES TUESDAY AND PERSIST IN THE VICINITY THROUGH THURSDAY NIGHT. HIGH PRESSURE WILL BUILD BACK IN FOR LATE NEXT WEEK INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... A POTENT SHORTWAVE PIVOTING AROUND THE BASE OF THE LONG-WAVE TROUGH EXTENDING OUT OF HUDSON BAY CANADA WILL PUSH OFFSHORE THIS EVENING...USHERING IN ANOTHER SURGE OF COLDER AIR OVER SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA. ALREADY SEEING SIGNIFICANT PRESSURE RISES OCCUR OVER THE NORTH CAROLINA MOUNTAINS...THE SOUTH CAROLINA UPSTATE AS WELL AS NORTHERN GEORGIA WHERE A SECONDARY SURGE OF STRONG COLD AIR ADVECTION IS INITIATING IN THE WAKE OF THE SHORTWAVE. WINDS WILL SHIFT TO A MORE SOLID DOWNSLOPE TRAJECTORY OVER THE NEXT FEW HOURS AS THE SHORTWAVE PUSHES OFFSHORE...WHICH WILL IN TURN EXPEDITE THE CLEARING PROCESS. EARLY EVENING SATELLITE AND SURFACE OBSERVATIONS ALREADY SHOW A RATHER LARGE CLEARING AREA STEADILY EXPANDING ACROSS THE UPPER SAVANNAH RIVER AREA AS WELL AS THE SOUTH CAROLINA MIDLANDS. ADJUSTED THE SKY FORECAST TO MATCH EXPECTED TRENDS OVER THE NEXT FEW HOURS WITH CLEAR TO MOSTLY CLEAR SKIES EXPECTED TO PREVAIL BY MIDNIGHT. LOWS FROM AROUND 30 WELL INLAND TO THE MID 30S AT THE COAST LOOK REASONABLE. GUSTY NORTHWEST WINDS WILL MAKE TEMPERATURES FEEL CONSIDERABLY COOLER WITH WIND CHILLS DROPPING WELL INTO THE 20S BY EARLY SUNDAY. LAKE WINDS...EXTENDED THE LAKE WIND ADVISORY UNTIL 5 AM SUNDAY. WINDS ON LAKE MOULTRIE WILL INCREASE TO A SOLID 20 KT LATER THIS EVENING AS A STRONGER SURGE OF COLD AIR MOVES ACROSS THE RELATIVELY WARMER LAKE WATERS. WAVES OF 1-2 FT WILL OCCUR... HIGHEST OVER THE CENTRAL AND SOUTHEAST PORTIONS OF THE LAKE. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... SUNDAY AND SUNDAY NIGHT...LARGE AND PROMINENT RIDGING ALOFT WILL BUILD IN FROM THE WEST. AT THE SURFACE...A 1030 MB HIGH WILL SHIFT EASTWARD INTO THE FORECAST AREA AND LINGER THROUGH THE OVERNIGHT. DEEP DRY AIR AND LARGE SCALE SUBSIDENCE WILL RESULT IN A DRY AND CLEAR DAY/NIGHT. COLD AIR ADVECTION WILL CONTINUE THROUGH THE DAY RESULTING IN COOL HIGH TEMPS. LOW LEVEL THICKNESSES SUPPORT HIGHS STRUGGLING TO REACH THE LOW 50S. WITH EXCELLENT RADIATIONAL COOLING CONDITIONS SUNDAY NIGHT...LOWS WILL BOTTOM OUT IN THE UPPER 20S AWAY FROM THE COAST. MONDAY THROUGH TUESDAY...THE UPPER RIDGE WILL FLATTEN OUT AND THE FLOW WILL BECOME MORE ZONAL IN RESPONSE TO A POSITIVELY TILTED TROUGH PUSHING INTO THE OH VALLEY. AS A RESULT A STRENGTHENING 150 KT UPPER LEVEL JET WILL EXTEND WEST TO EAST ACROSS THE UPPER MIDWEST AND MID ATLANTIC. THIS WILL HELP DRIVE SURFACE LOW AND COLD FRONT DEVELOPMENT OVER THE LOWER MS VALLEY BY TUESDAY MORNING. THE FRONT WILL CONTINUE TO DRIFT EASTWARD WITH PRECIP EXPECTED TO BE OUR THE DOORSTEP OF THE FORECAST AREA BY TUESDAY AFTERNOON. EXPECT MONDAY TO BE DRY WITH INCREASING HIGH CLOUDS AND TEMPS RIGHT AROUND NORMAL. TUESDAY CONTINUES TO FEATURE A DRY MORNING AND POPS INCREASING INTO THE CHANCE RANGE FOR THE AFTERNOON. AS OF RIGHT NOW...MODELS ARE IN GOOD AGREEMENT KEEPING THE BULK OF THE PRECIP TO OUR WEST THROUGH THE DAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... TUESDAY NIGHT THROUGH THURSDAY NIGHT LOOK FAIRLY ACTIVE DUE TO A PLETHORA OF UPPER DISTURBANCES RIPPLING THROUGH THE BROAD EASTERN UNITED STATES TROUGH. A WEAK FRONT SHOULD REMAIN DRAPED ACROSS THE FORECAST AREA WITH NUMEROUS SURFACE WAVES RIDING ALONG IT. WE KEPT CHANCE POPS IN THE FORECAST THROUGH THURSDAY...TAPERING OFF THURSDAY NIGHT. COOL...DRY HIGH PRESSURE WILL BUILD IN FRIDAY THROUGH SATURDAY. && .AVIATION /23Z SATURDAY THROUGH THURSDAY/... CLOUDS WILL QUICKLY SCOUR OUT THIS EVENING YIELDING CLEAR SKIES. GUSTY WINDS WILL PERSIST FOR MUCH OF THE HIGHEST WITH WINDS GUSTING 25-30 KT AT TIMES...MAINLY THROUGH 06Z. ALTHOUGH WINDS ALOFT WILL BE INCREASING...IT APPEARS SURFACE WINDS WILL REMAIN ELEVATED ENOUGH TO PRECLUDE LOW-LEVEL WIND SHEAR. EXTENDED AVIATION OUTLOOK...INCREASING CHANCES FOR SUB-VFR CONDITIONS LATE TUESDAY AND WEDNESDAY AS A COLD FRONT DROPS SOUTH INTO THE AREA. && .MARINE... TONIGHT...WINDS WILL INCREASE EVEN MORE TONIGHT AS A SECONDARY SURGE OF COLD AIR PUSHES OFF THE COAST AND INTERACTS WITH THE RELATIVE WARMER ATLANTIC WATERS. SMALL CRAFT ADVISORIES LOOKS WELL PLACED...BUT OPTED TO UPGRADE TO A GALE WARNING FOR THE GEORGIA OFFSHORE WATERS WHERE SIGNIFICANTLY WARMER WATERS ASSOCIATED WITH THE WESTERN WALL OF THE GULF STREAM ARE LOCATED. YESTERDAY/S 1KM MODIS SEA SURFACE TEMPERATURE DATA INDICATED WATER TEMPERATURES QUICKLY WARM FROM THE LOWER-MID 50S AROUND 20 NM TO THE LOWER 70S BEYOND 40 NM. RUC AND H3R BOUNDARY LAYER WIND FORECAST SUGGEST WINDS COULD EASILY REACH SOLID GALES OF 30-35 KT WITH GUSTS TO 40 KT IN THE OUTER HALF OF THE GEORGIA OFFSHORE ZONES WHERE THE WARMER WATER TEMPERATURES WILL FAVOR MORE INTENSE VERTICAL MIXING. OBSERVATIONS FROM 41004 WERE ALREADY GUSTING NEAR 35 KT AT 29/22Z SO THINK A GALE WARNING IS CERTAINLY WARRANTED ATTM AS WINDS INCREASE FURTHER. WILL WORD THE HIGHEST WINDS BEYOND 40 NM IN BOTH THE GALE WARNING ITSELF AND THE COASTAL WATERS FORECAST. SEAS WILL BUILD AS HIGH 9 FT OFFSHORE...BUT WILL ACTUALLY SUBSIDE A BIT NEAR THE IMMEDIATE COAST AS THE OFFSHORE FLOW INTENSIFIES. SUNDAY THROUGH THURSDAY...HIGH PRESSURE WILL BUILD INTO THE AREA ON SUNDAY. THE MORNING WILL CONTINUE TO SEE ELEVATED SEAS AND STRONG NW WINDS AS THE WATERS ARE CAUGHT IN THE PINCHED GRADIENT BETWEEN THE APPROACHING HIGH AND DEPARTING LOW. CONDITIONS SHOULD IMPROVE QUICKLY INTO THE AFTERNOON...ALLOWING FOR ALL SMALL CRAFT ADVISORIES TO COME DOWN. THINGS WILL THEN BE QUIET THROUGH MONDAY AS THE HIGH PASSES OVER THE AREA. INCREASING SOUTHWEST FLOW AHEAD OF THE NEXT FRONT MAY PUSH WINDS AS HIGH AS 15-20 KT WITH SEAS REACHING 5 FT OVER THE OUTER PORTIONS BY TUESDAY. A STRONGER SURGE WILL OCCUR LATE NEXT WEEK WHEN COLD HIGH PRESSURE BUILDS OVER THE WATERS. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...LAKE WIND ADVISORY UNTIL 5 AM EST SUNDAY FOR SCZ045. MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EST SUNDAY FOR AMZ330-350-352- 354. GALE WARNING UNTIL 5 AM EST SUNDAY FOR AMZ374. && $$ SYNOPSIS... NEAR TERM...ST SHORT TERM...BSH LONG TERM...BSH AVIATION...ST MARINE...ST ______________________________________________________________________ --- Site: KCLE --- --- Site: KCRP --- KCRP - Reference: ['enhanced modis sst composite.) as the sfc ridge axis enters the cwa '] 555 FXUS64 KCRP 010959 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 359 AM CST SUN JAN 1 2012 .SHORT TERM (TODAY THROUGH MONDAY)...CONCUR WITH THE GFS WITH REGARD TO THE UPPER PATTERN WHICH PROGS AN UPPER TROUGH...CURRENTLY OVER THE CNTRL CONUS BASED ON WATER VAPOR IMAGERY/STREAMLINE DATA...TO MOVE EWD AND OVER THE ERN CONUS BY MONDAY ALONG WITH AN UPPER RIDGE WITH AXIS ENTERING THE ROCKIES. THE ASSOCIATED COLD FRONT... CURRENTLY APPROACHING THE CWA FROM THE NORTH BASED ON MSAS DATA...IS EXPECTED TO MOVE ACRS THE CWA/MSA TODAY. ANTICIPATE AT LEAST ISOLD SHOWER ACTIVITY OVER THE CWA ALONG THE FRONT (NAM/GFS QPF). THE FOG WILL DISSIPATE AFTER FRONTAL PASSAGE. CONSIDERING THE NAM WIND/NAM MSLP FALLS/LOCAL WRF-ARW WIND OUTPUT/GFS WIND OUTPUT...EXPECT BREEZY/WINDY CONDITIONS OVER THE CWA AFTER FRONTAL PASSAGE YET BELOW WIND ADVISORY CRITERIA. THICKNESS VALUES REVEAL THAT THE MUCH COLDER AIR WILL REMAIN NORTH OF THE CWA. NEVERTHELESS...COLDER CONDITIONS ARE EXPECTED DRG THE PERIOD. EXPECT MAX TEMPS TODAY TO REMAIN IN THE 60S. WL DEFER TO THE DETERMINISTIC NAM (WITH MINOR ADJUSTMENTS) WITH REGARD TO TEMPS TNGT/ MONDAY...WITH READINGS IN THE MID/UPPER 30S TONIGHT...AND THE LOWER 60S MONDAY. DRY ATMOSPHERIC CONDITIONS EXPECTED TONIGHT/MONDAY. && .MARINE...ISOLATED/SCATTERED SHOWERS EXPECTED ALONG A COLD FRONT THIS MORNING. EXPECT THE FOG TO DISSIPATE AND SCA CONDITIONS OVER THE COASTAL WATERS AFTER FRONTAL PASSAGE (ESPECIALLY OVER THE OFFSHORE WATERS WHEN CONSIDERING WARM SST VALUES BASED ON SPORT ENHANCED MODIS SST COMPOSITE.) AS THE SFC RIDGE AXIS ENTERS THE CWA FROM THE NW...WIND WILL DECREASE FROM WEST TO EAST OVER THE CWA BEGINNING LATE THIS AFTN. EXPECT CONDITIONS TO FALL BELOW SCA OVER THE BAYS BY 00Z MONDAY...NEARSHORE BY 03Z MONDAY...YET CONTINUE OVER THE OFFSHORE WATERS THROUGH 23Z MONDAY WHEN CONSIDERING SEA HEIGHTS FROM WAVEWATCH OUTPUT. && .FIRE WEATHER...BASED ON EXPECTED RELATIVE HUMIDITY/WIND...WILL ISSUE AN RFD FOR ELEVATED FIRE DANGER CONDITIONS DRG THE 18Z-00Z MONDAY PERIOD. NOT SUFFICIENTLY CONFIDENT IN RED FLAG CONDITIONS. && .LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...LIGHT WINDS AND A DRY AIRMASS MONDAY NIGHT/TUE MORNING WILL ALLOW MN TEMPS TO BRIEFLY DROP TO AROUND FREEZING ACROSS THE NRN TIER OF THE CWA. MID 30S ARE EXPECTED FARTHER S ACROSS THE INTERIOR COASTAL BEND TO NEAR 40 ALONG THE RIO GRANDE AND ALONG THE COAST. ALL OF THE MODELS ARE IN AGREEMENT WITH THE SFC HIGH SHIFTING EAST THROUGH TUE WITH WINDS INCREASING OUT OF THE S. THIS WILL BEGIN TO BRING LOW LEVEL MOISTURE/HIGHER DEWPOINTS BACK INTO S TX THROUGHOUT THE DAY LEADING TO GRADUAL WARMING INTO WED. ALSO WITH THE INCREASING DEWPOINTS...PATCHY FOG WILL BE POSSIBLE WED NITE/TUE MORN. MOSTLY CLOUDY CONDITIONS ARE EXPECTED WED/WED NIGHT AHD OF ANOTHER FRONTAL PASSAGE. TIMING AND STRENGTH OF THIS FRONT IS TRICKY AS MODELS DIFFER ON STRENGTH AND POSITION OF AN UPPER TROUGH AXIS...BUT THEY DO ALL SHOW A BAGGY TROUGH MOVG ACROSS S TX SOMETIME THU. MODELS ARE SHOWING NO TO VERY LOW PRECIP AMOUNTS AND MOSTLY ACROSS THE OFFSHORE WATERS. DUE TO LOW CONFIDENCE IN MODEL SOLNS...WILL CONTINUE WITH SILENT 10 POPS BEGINNING ON WED AND CONTINUING THROUGH THE EXTENDED DUE TO YET ANOTHER POSSIBLE FRONTAL PASSAGE ON SAT. AS FOR TEMPS...DESPITE A COLD FRONT ON THU...MX TEMPS THROUGH THE EXTENDED ARE PROGD TO BE SLIGHTLY ABV NORMAL FOR THE MOST PART WITH MN TEMPS NEAR NORMAL AT TIMES BUT GENERALLY ABOVE AS WELL. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 67 41 62 35 67 / 30 0 0 0 10 VICTORIA 64 35 61 31 64 / 20 0 0 0 0 LAREDO 66 39 63 39 69 / 20 0 0 0 10 ALICE 66 39 63 35 66 / 30 0 0 0 10 ROCKPORT 65 43 60 38 63 / 20 0 0 0 0 COTULLA 64 34 62 31 66 / 10 0 0 0 10 KINGSVILLE 67 40 63 32 67 / 30 0 0 0 10 NAVY CORPUS 65 46 59 43 66 / 30 0 0 0 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...DENSE FOG ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR THE FOLLOWING ZONES: ARANSAS...BEE...CALHOUN...GOLIAD...JIM WELLS...KLEBERG...LIVE OAK...NUECES...REFUGIO...SAN PATRICIO...VICTORIA. GM...SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 6 AM CST MONDAY FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. DENSE FOG ADVISORY UNTIL 8 AM CST THIS MORNING FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS... BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O'CONNOR... COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM... COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM. SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 6 PM CST THIS EVENING FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O'CONNOR. SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 9 PM CST THIS EVENING FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM. && $$ WC/87...SHORT TERM TE/81...LONG TERM ______________________________________________________________________ KCRP - Reference: ['enhanced modis sst composite product. the after early wednesday... '] 066 FXUS64 KCRP 211028 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 428 AM CST SAT JAN 21 2012 .SHORT TERM (TODAY THROUGH SUNDAY)...MODELS CONTINUE TO SWING A H5 TROUGH THROUGH OKLAHOMA WHICH WILL BRING A COLD FRONT THROUGH TEXAS. THE FRONT WILL CONTINUE A SLOW MOVEMENT ACROSS CENTRAL AND SOUTH TEXAS BEFORE PUSHING THROUGH DEEP SOUTH TEXAS AND WASHING OUT. IN THE MEANTIME...LOW LEVEL MOISTURE WILL CONTINUE TO POOL AHEAD OF THE FRONT AND WINDS WILL BE LIGHT. THIS WILL CONTINUE TO ALLOW FOR DENSE FOG DEVELOPMENT THIS MORNING ACROSS MOST OF SOUTH TEXAS. THERE IS AN AREA OF LOW CLOUDS THAT HAS BEEN HANGING AROUND THE NORTHEASTERN PORTIONS OF THE CWA...WHICH HAVE PRETTY MUCH HINDERED MUCH OF DROP IN VISIBILITY. THEREFORE...HAVE ISSUED A DENSE FOG ADVISORY FOR ALL COUNTIES WITH THE EXCEPTION OF VICTORIA AND CALHOUN. EXPECTING LAREDO TO BE LATE IN DEVELOPING FOG...BUT WITH TEMPERATURES STILL DROPPING AND WINDS BECOMING LIGHTER...SHOULD SEE FOG BECOMING DENSE WITHIN THE NEXT COUPLE OF HOURS. WITH DRIER AIR REMAINING WELL NORTH OF THE AREA...THE FOG MAY LINGER WELL INTO THE LATE MORNING HOURS. TODAY WILL BE MUCH COOLER THAN YESTERDAY AS A SLIGHTLY COOLER AIRMASS WILL MOVE OVER THE AREA. TEMPERATURES MAY ALSO BE AFFECTED BY THE LOW CLOUD AND DENSE FOG DEVELOPMENT THIS MORNING...WHICH WOULD HINDER MUCH HEATING. NORTH TO NORTHEAST WINDS WILL DEVELOP AFTER THE FRONTAL PASSAGE... BUT WILL QUICKLY BECOME ONSHORE FLOW LATE TONIGHT. A BIT OF DRYING WILL OCCUR THIS AFTERNOON/EVENING AFTER THE PASSAGE. PATCHY FOG WILL IS THEN EXPECTED TO DEVELOP AGAIN TONIGHT...HOWEVER NOT THINKING MUCH IN THE WAY OF DENSE. A STRONGER FRONT WILL MOVE THROUGH THE AREA LATE SUNDAY. THIS FRONT SHOULD DRY THINGS OUT MORE. THERE IS A POSSIBILITY FOR SOME PATCHY LIGHT RAIN/SPRINKLES TO DEVELOP ACROSS THE NORTHEASTERN PORTIONS OF THE CWA...WHERE LIFT AND LOW CONDENSATION PRESSURE DEFICITS EXIST. HOWEVER...DUE TO LACK OF HIGH MOISTURE AVAILABILITY...WILL ONLY CARRY A LESS THAN 20 POPS. && .LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...THE DETERMINISTIC NAM/GFS/ECMWF/CANADIAN LIFT AN UPPER TROUGH EAST OF THE SRN PLAINS SUNDAY NIGHT WHILE MOVG THE NEXT UPPER DISTURBANCE TOWARD THE WEST COAST. SYNOPTIC SCALE LIFT ASSOCIATED WITH THIS NEXT SYSTEM IS PROGD BY ALL OF THE FOREGOING MODELS TO ENTER TEXAS BY TUESDAY NIGHT/ WEDNESDAY. THUS...CONCUR WITH THE ECMWF/GFS GENERATING ONSHORE SFC WIND OVER THE COASTAL WATERS APPROACHING THE SCA WIND CRITERION OF 20KT (PROBABLY 15-20KT OVER THE NEARSHORE WATERS AND 20-25KT OVER THE OFFSHORE WATERS WHEN CONSIDERING SST VALUES PER THE SPORT ENHANCED MODIS SST COMPOSITE PRODUCT. THE AFTER EARLY WEDNESDAY... MODELS DIVERGE REGARDING TIMING WITH THE SLOWER CANADIAN/GFS DEPICTING THE UPPER TROUGH AXIS/LOW CENTER STILL WEST OF THE CWA THURSDAY WHILE THE ECMWF MOVES THE AXIS EAST OF THE CWA/MSA (STRONG Q-VECTOR DIVERGENCE THURSDAY OVER THE CWA/MSA THURSDAY.) NEVERTHELESS...THE ASSOCIATED COLD FRONT IS PROGD BY THESE THREE MODELS TO MOVE ACRS THE CWA WEDNESDAY THEN OFFSHORE WEDNESDAY NIGHT/EARLY THURSDAY. THUS...THE COUPLING BETWEEN SURFACE AND UPPER FORCING EXPECTED TO GENERATE AT LEAST SCT CONVECTION WEDNESDAY. (GFS PROGS STRONGLY NEGATIVE LI VALUES/CAPES ABOVE 1500 J/KG/LIMITED CIN.) THE GFS SOUNDINGS DEPICT BRN VALUES IN THE MULTICELL AND SUPERCELL RANGES. FOR THURSDAY...THE ISSUE IS WHETHER SYNOPTIC SCALE LIFT WILL REMAIN OVER THE CWA/MSA OR SHIFT EAST. CONFIDENCE IN ECMWF GREATER THAN THAT OF THE GFS. NEVERTHELESS... WILL MAINTAIN LOW POPS TO ACCOUNT FOR UNCERTAINTY IN TIMING OF UPPER FORCING. FRIDAY...THE GFS/ECMWF PROG SYNOPTIC SCALE DESCENT. THE CANADIAN OUTPUT (ENDING AT 00Z FRIDAY) SUGGESTS A SLOWER SOLUTION. NEVERTHELESS...CONCUR WITH THE SYNOPTIC SCALE DESCENT SCENARIO. THUS...DRY FRIDAY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 75 58 79 55 71 / 10 10 10 10 10 VICTORIA 70 53 76 50 71 / 10 10 10 10 10 LAREDO 79 61 83 54 77 / 0 0 10 10 10 ALICE 78 58 82 55 74 / 0 10 10 10 10 ROCKPORT 69 58 75 56 66 / 10 10 10 10 10 COTULLA 76 53 81 48 74 / 0 0 10 10 10 KINGSVILLE 79 58 81 56 73 / 0 10 10 10 10 NAVY CORPUS 72 58 75 58 67 / 10 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE FOLLOWING ZONES: ARANSAS...BEE...DUVAL...GOLIAD...JIM WELLS...KLEBERG...LA SALLE...LIVE OAK...MCMULLEN...NUECES... REFUGIO...SAN PATRICIO...WEBB. GM...NONE. && $$ CB/85...SHORT TERM WC/87...LONG TERM ______________________________________________________________________ KCRP - Reference: ['sst values (sport enhanced modis sst composite)...increased'] 547 FXUS64 KCRP 301551 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 951 AM CST MON JAN 30 2012 .DISCUSSION...CONSIDERING THE NAM AND GFS DETERMINISTIC OUTPUT AND SST VALUES (SPORT ENHANCED MODIS SST COMPOSITE)...INCREASED OFFSHORE WIND TO THE SCEC CATEGORY. BASED ON GFS/NAM SOUNDINGS... THUNDERSTORM ACTIVITY LIKELIHOOD IS LOW. YET...WILL RETAIN ISOLD THUNDER FOR THIS AFTN OWING TO SIGNIFICANT SYNOPTIC SCALE FORCING ASSOCIATED WITH APPROACHING UPPER DISTURANCE. THE LOCAL ARW AND THE NAM PROG MAX TEMPS GREATER THAN CURRENT FCST FOR THE WEST... YET RAINFALL (LRD CURRENTLY REPORTING LIGHT RAIN)/CLOUDS SHOULD LIMIT TEMP RISE. WL RETAIN CURRENT TEMPS FOR NOW. && .PREV DISCUSSION... /ISSUED 615 AM CST MON JAN 30 2012/ DISCUSSION...SEE 12Z AVIATION DISCUSSION. AVIATION...CIGS WILL FALL TODAY AS RAIN WITH ISENTROPIC UPGLIDE HELP TO LOWER CIGS. EXPECTING CIGS TO FALL TO IFR AROUND 18Z AT KLRD...MVFR LATE MORNING/EARLY AFTERNOON AT KCRP AND KALI...AND NOT TIL LATE AT KVCT. MAY SEE SOME IMPROVEMENT AFTER SUNSET JUST FOR A SHORT TIME (MAINLY TAFS EAST OF KLRD)...BUT CIGS WILL GO DOWN AGAIN IN THE EVENING/OVERNIGHT...WITH IFR CONDITIONS AT KCRP AND KVCT AND LIFR AT KALI AND KLRD BEFORE THE FORECAST PERIOD ENDS. FOG WILL ALSO BE AN ISSUE...COULD BECOME DENSE RIGHT AT THE END OF THE FORECAST PERIOD KALI AND KLRD BUT FOR NOW WILL JUST GO WITH MVFR BR AT ALL BUT KALI WHERE WILL GO IFR. WINDS NOT TOO BAD TODAY...BECOMING SOUTHEAST DURING THE DAY BUT LESS THAN 15 KNOTS AND NOT MUCH IN GUSTS DUE TO LIMITED MIXING. LITTLE THUNDER EXPECTED SO NOT MENTIONED IN TAFS ALTHOUGH AN ISOLATED RUMBLE CANNOT BE RULED OUT. PREV DISCUSSION... /ISSUED 424 AM CST MON JAN 30 2012/ SHORT TERM (TODAY THROUGH TUESDAY)...SATELLITE VAPOR IMAGERY SHOWING AN UPPER TROUGH MOVING SLOWLY NORTHEAST...WITH MOISTURE ENHANCEMENT/THICKEST MID HIGH CLOUDS MISSING AREA (MAINLY SOUTH AND NORTHWEST OF CWFA). NEVERTHELESS...ENERGY FROM SYSTEM (Q/G FORCING AND UPPER LEVEL DIFFLUENCE) ALONG WITH SOME ISENTROPIC UPGLIDE (MAINLY 300K-305K) WILL PROVIDE A CHANCE FOR RAIN THROUGH TONIGHT. GIVEN STABILITY THROUGH 850MB...THINK MOST OF THE RAIN WILL BE STRATIFORM IN NATURE...AND SOME OF IT MAY BE VIRGA AT LEAST INITIALLY. HOWEVER...COULD GET SOME THUNDER IN THE AFTERNOON/EVENING AS MID LEVEL TEMPERATURES COOL A BIT. MOST OF THE PRECIP SHOULD BEGIN ALONG THE RIO GRANDE/SOUTHERN BRUSH COUNTY THEN SLIDE NORTHEAST DURING THE NEXT 12 TO 18 HOURS. MOST OF THE RAIN WILL END FROM WEST TO EAST THIS EVENING/OVERNIGHT...BUT COULD SEE A FEW COASTAL SHOWERS EARLY TUESDAY MORNING AS INSTABILITY RETURNS AND MOISTURE REMAINS (CONVERGENCE SHOWERS). WILL MAINTAIN A SLIGHT CHANCE FOR SHOWERS/THUNDER ON TUESDAY NORTHEAST WITH SUFFICIENT INSTABILITY ALTHOUGH UPPER LEVEL FORCING WILL BE ABSENT. RAINFALL WILL LIKELY BE OVER BY TUESDAY AFTERNOON BUT FOR NOW KEPT RAIN IN. CLOUDS/MOISTURE RAIN-COOLED AIR WILL KEEP TEMPERATURES FROM CLIMBING TOO HIGH TODAY WITH MANY AREAS NOT GETTING TO 70F. MILD TONIGHT WITH TEMPERATURES NEAR THE COAST LIKELY REMAINING STEADY IF NOT RISING OVERNIGHT. FOG COULD BE AN ISSUE MOST AREAS BY TUESDAY MORNING (MAYBE SOME SEA FOG TOO BUT IT MAY BE A BIT EARLY FOR SEA FOG FORMATION). WARMER ON TUESDAY WITH SOME CLEARING OUT TO THE WEST...WITH SOME 80S EXPECTED OVER THE SOUTHERN TIER. MARINE (TODAY THROUGH TUESDAY)...FLOW GRADUALLY BECOMES MORE SOUTHERLY THROUGH THE PERIOD. CHANCE FOR RAIN/SHOWERS TODAY WITH POSSIBLE THUNDER LATE...THEN SLIGHT CHANCE THUNDER TONIGHT AND TUESDAY AS ACTIVITY (IF ANY) BECOMES MORE CONVECTIVE TUESDAY. LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...EXTENDED FORECAST REMAINS A CHALLENGE THIS MORNING AS GUIDANCE CONTINUES TO DIFFER WITH EACH MODEL RUN AND FORECAST CONFIDENCE IS LOW. WED SHOULD FEATURE THE APPROACH OF A WEAK FRONT FROM THE NORTH WHICH SHOULD DRIFT INTO THE AREA WITH ISOLATED SHOWERS POSSIBLE...PRIMARILY ACROSS ENE COUNTIES WHERE BEST MOISTURE DEPTH IS EXPECTED TO BE LOCATED. GFS WANTS TO STALL THE BOUNDARY ALONG CRP/BRO CWA LINE WED NIGHT BEFORE WORKING BACK NORTH AS A WARM FRONT ON THURS WHILE THE NAM AND ECMWF ARE A LITTLE FARTHER NORTH WITH STALLING OF THE FRONT. THE LATTER MODELS INDICATE AN INCREASE OF RAIN CHANCES FOR WED NIGHT AND THURS WITH A FRONT STALLED ACROSS THE AREA WHILE THE GFS IS LESS IMPRESSIVE AND MOVES THE BOUNDARY BACK NORTH FASTER. FOR NOW WILL GO WITH A SLIGHT CHANCE OF RAIN/SHOWERS ON THURS WITH LOW END CHANCES ACROSS SOUTHERN COUNTIES...BUT AGAIN CONFIDENCE IS LOW AND PRECIP CHANCES MAY NEED TO BE INCREASED IN LATER FORECAST PACKAGES. GULF MOISTURE THEN POURS BACK INTO THE REGION IN THE LOWER LEVELS OF THE ATMOSPHERE THURS/THURS NIGHT AHEAD OF NEXT SIGNIFICANT COLD FRONT WHICH THIS FORECAST PACKAGE BRINGS THROUGH FRI AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS MAY DEVELOP ALONG THE FRONT FRIDAY WITH AN ISOLATED STRONG STORM POSSIBLE ACROSS THE COASTAL BEND. FOR NOW WILL AGAIN BE CONSERVATIVE WITH RAIN CHANCES GIVEN LOW FORECAST CONFIDENCE. STRONG WINDS POSSIBLE BEHIND THE FRONT AS HIGH PRESSURE BUILDS INTO THE AREA RESULTING IN DRYING CONDITIONS. VORTICITY SWINGING AROUND MID LEVEL LOW OVER THE WEEKEND MAY TRY TO SQUEEZE OUT AN ISOLATED SHOWER OVER THE WEEKEND BUT MOISTURE WILL LIKELY BE LACKING FOR WIDESPREAD PRECIP. TEMPS THROUGH MID WEEK TO BE ABOVE NORMAL FOR BOTH MAX AND MINS. A RETURN TO NEAR SEASONABLE VALUES THEN EXPECTED AFTER FRONTAL PASSAGE LATER THIS WEEK AND WEEKEND. HIGH LOW LEVEL MOISTURE VALUES AND LIGHT WINDS AT NIGHT SHOULD LEAD TO AREAS OF FOG AT TIMES DURING MIDWEEK NIGHT TIME HOURS WITH PATCHY SEA FOG ALSO POSSIBLE. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 68 61 79 63 81 / 40 40 10 10 10 VICTORIA 69 57 76 62 79 / 20 40 20 10 20 LAREDO 67 61 81 62 82 / 50 20 10 10 10 ALICE 68 59 81 62 82 / 50 30 10 10 10 ROCKPORT 68 61 70 62 75 / 30 40 20 10 20 COTULLA 63 55 78 59 81 / 40 30 10 10 10 KINGSVILLE 70 59 80 63 83 / 50 30 10 10 10 NAVY CORPUS 69 63 74 64 76 / 40 40 20 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ WC/87...SHORT TERM ______________________________________________________________________ KCRP - Reference: ['(buoys/sport enhanced modis sst composite) to the mid/upper 60s sst ', 'values over the offshore waters (modis sst). retained the sca for '] 290 FXUS64 KCRP 111039 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 439 AM CST SAT FEB 11 2012 .SHORT-TERM (TODAY THROUGH SUNDAY)...OWING TO UPPER CONVERGENCE OVER THE SRN PLAINS/NRN TEXAS TODAY...SFC HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE CWA/MSA. CONCUR WITH THE NAM/LOCAL ARW DETERMINISTIC OUTPUT THAT MAX TEMPS TODAY WILL RANGE FROM THE LOWER 50S NORTHEAST TO NEAR 60S SW. CONCUR WITH THE GFS THAT AN UPPER LEVEL DISTURBANCE...CURRENTLY APROACHING WEST CNTRL MEXICO...WILL ENTER THE CWA/MSA OVERNIGHT. THE GFS PROGS ISENTROPIC LIFT TO COMMENCE TONIGHT AND CONTINUE THROUGH SUNDAY. BASED ON GFS CONDENSATION PRESSURE DEFICITS AT THE 295K AND 300K ISENTROPIC LEVELS... ANTICIPATE LIGHT RAIN TO COMMENCE OVER THE CWA AFTER 06Z SUNDAY. WITH REGARD TO TEMPS TONIGHT...SFC DEW POINTS ARE EXPECTED TO FALL BELOW FREEZING. YET...WEAK CAA AND INCREASING CLOUD COVER WILL LIMIT RADIATIONAL COOLING AND RESULT IN MIN TEMPS ABOVE FREEZING. EXPECT LOWEST MIN TEMPS IN THE UPPER 30S OVER THE NORTH CENTRAL/NE CWA. SUNDAY...COOL AND RAINY CONDITIONS AS EXPECT PCPN TO INCREASE FROM SW TO NE ACROSS THE CWA/MSA. ANTICIPATE MAX TEMPS TO RANGE IN THE UPPER 40S/NEAR 50 NW TO MID/UPPER 50S SE...CLOSE TO THE NAM DETERMINISTIC OUTPUT. GFS SOUNDINGS SUGGEST STRATIFORM RAIN. DESPITE THE UPPER DISTURBANCE...NOT EVEN ELEVATED THUNDERSTORM ACTIVITY EXPECTED WHEN CONSIDERING THE THERMODYNAMIC PROFILE. && .MARINE...AS CAA AND SURFACE HIGH PRESSURE BUILDS OVER THE REGION... EXPECT MODERATE TO STRONG OFFSHORE FLOW OVER THE COASTAL WATERS. DETERMINISTIC NAM SUGGEST AT LEAST SCA WIND OVER THE OFFSHORE WATERS YET SCEC LIKELY OVER THE NEARSHORE WATERS. CONCUR WITH THIS SOLN ESPECIALLY WHEN CONSIDERING 50S/NEAR 60S SST VALUES NEAR THE COAST (BUOYS/SPORT ENHANCED MODIS SST COMPOSITE) TO THE MID/UPPER 60S SST VALUES OVER THE OFFSHORE WATERS (MODIS SST). RETAINED THE SCA FOR THE OFFSHORE WATERS AND EXTENDED SUCH TO 00Z SUNDAY. WILL MAINTAIN SCEC OVER THE NEARSHORE WATERS TODAY. && .LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...CONVECTION ASSOCIATED WITH UPPER LEVEL DISTURBANCE SHOULD BE ONGOING AT THE BEGINNING OF THE LONG TERM FORECAST PERIOD. THINK RAIN IS STILL LIKELY...ALTHOUGH QPF HAS DECREASED A BIT FROM EARLIER MODEL RUNS. HAVE ALSO NOTICED THAT LOW TO MID LEVEL OMEGA SEEMS A BIT WEAKER...EXCEPT IN THE NORTHEAST PORTION OF THE FORECAST AREA. THIS IS LIKELY A FACTOR IN THE LOWER PROGEGD QPF. HAVE NOT MADE TOO MANY CHANGES IN THIS PART OF THE FORECAST PERIOD...STILL GOING LIKELY POPS WITH SHOWERS AND A CHANCE OF THUNDERSTORMS OVERNIGHT. UPPER LEVEL JET POSITION STILL FAVORABLE FOR CONVECTIVE PRECIP. A WEST TO NORTHWEST FLOW IS THEN FORECAST TO DEVELOP MONDAY AFTERNOON AND SHOULD QUICKLY END PRECIP CHANCES FROM WEST TO EAST ACROSS THE AREA. TEMPERATURES ARE ALSO FORECAST TO INCREASE SIGNIFICANTLY IN THE EARLY PART OF THE WEEK...WITH LOWER 70S BY MONDAY...AND MID TO UPPER 70S TUESDAY AND WEDNESDAY. MOISTURE BEGINS TO RETURN BY TUESDAY AFTERNOON AS WINDS SHIFT BACK TO THE SOUTHEAST AND BEGIN TO INCREASE. A COUPLE OF UPPER LEVEL LOWS WILL AFFECT THE AREA THROUGH THE SECOND HALF OF THE WEEK. THE FIRST LOW EJECTS FROM CENTRAL CALIFORNIA...ACROSS THE ROCKIES AND INTO THE MIDWEST BRINGING A COLD FRONT THROUGH THE FORECAST AREA EARLY THURSDAY. RAIN CHANCES RETURN ON WEDNESDAY AHEAD OF THE FRONT...BUT PWAT VALUES ARE ONLY FORECAST TO BE AROUND 1 INCH FOR MUCH OF THE AREA...WITH HIGHER AMOUNTS IN THE NORTHEAST. WITH CONTINUED CHANGES IN TIMING OF THE FRONT...CONTINUING TO GO CONSERVATIVE ON POPS WITH 20 TO 30 POPS ACROSS THE AREA. COOLER TEMPERATURES WILL RETURN FOR LATE IN THE WEEK. A SECOND LOW OFF THE CALIFORNIA COAST IS CURRENTLY PROGGED TO BECOME AN OPEN WAVE AND PUSH ACROSS THE SOUTHWEST US. THIS WILL BRING MORE RAIN CHANCES BY THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 57 46 57 56 72 / 0 10 50 60 40 VICTORIA 53 37 51 48 68 / 0 10 40 60 50 LAREDO 62 43 53 48 70 / 0 20 60 60 20 ALICE 58 43 55 53 71 / 0 10 60 70 30 ROCKPORT 56 45 55 54 70 / 0 10 50 60 40 COTULLA 57 40 47 45 68 / 0 10 60 60 20 KINGSVILLE 58 46 57 56 72 / 0 10 50 60 30 NAVY CORPUS 57 49 58 58 72 / 0 10 50 60 40 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. && $$ WC/87...SHORT TERM PZ/83...LONG TERM ______________________________________________________________________ KCRP - Reference: ['based on the modis enhanced sst composite product.) sca conditions'] 390 FXUS64 KCRP 241039 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 439 AM CST FRI FEB 24 2012 .SHORT TERM (TODAY THROUGH SATURDAY)...IN RESPONSE TO THE UPPER TROUGH MOVG ACRS THE PLAINS...A COLD FRONT WILL CONTINUE TO MOVE ACRS THE REGION THIS MORNING. ISOLD CONVECTION WILL CONTINUE TO OCCUR ALONG THE FRONT. THE NAM PROGS AND MSAS ANALYSES REVEAL... STRONG PRESSURE RISES TO THE N/NW BEHIND THE FRONT. EXPECT SUSTAINED SFC WIND TO REACH AS HIGH AS DEPICTED BY THE DETERMINSITIC NAM AND LOCAL ARW. WL MAINTAIN THE WIND ADVSY AS SUSTAINED WIND OR FREQUENT GUSTS SHOULD REACH CRITERION. (CAVEAT... WIND MAY FALL BELOW ADSY CRITERION A FEW HOURS BEFORE EXPIRATION.) AFTER FRONTAL PASSAGE...NAM SOUNDINGS MAINTAIN MID/UPPER MOIST CONDITIONS. ANTICIPATE ISOLD SHOWER ACTIVITY THROUGH EARLY AFTN MAINLY OVER THE SRN CWA. CONCUR WITH THE NAM WITH REGARD TO THE TEMP TREND AFTER FROPA TODAY WITH READINGS FALLING INTO THE 50S BY MID MORNING YET RISING TO THE LOWER 60S BY AFTN. CONCUR WITH THE NAM/GFS THAT SYNOPTIC SCALE LIFT ASSOCIATED WITH THE UPPER DISTURBANCE (CURRENTLY SW OF TEXAS AS DEPICTED IN WATER VAPOR IMAGERY/STREAMLINE DATA) WILL ENTER THE CWA/MSA AFTER 00Z SAT THEN EXIT BY 18Z SAT. EXPECT THIS SYSTEM TO GENERATE SCT SHOWER ACTIVITY WITH ISOLATED ELEVATED THUNDERSTORMS TNGT/SAT. ANTICIPATE LOW TEMPS SLIGHTLY WARMER THAN NAM MOS OWING TO CLOUD COVER/DECREASING CCA. YET...COLDER WITH READINGS IN THE 40S. FCSTG HIGHS SLIGHTLY WARMER THAN NAM MOS YET COOL WITH READINGS IN THE 50S WHICH IS REASONABLE CONSIDERING CLOUD COVER/AIRMASS. && .MARINE...COLD FRONT ENTERING THE COASTAL WATERS AT THIS TIME. EXPECT SEA FOG TO DISSIPATE AND WL ALLOW THE DENSE FOG ADVSY TO EXPIRE AT 12Z. WILL MAINTAIN THE GALE WARNINGS FOR THE COASTAL WATERS AND SCA OVER THE BAYS WHEN CONSIDERING STRONG MSLP RISES AND RECENT OBSERVATIONS OVER LAND (ALSO CONSIDERING THE SST VALUES BASED ON THE MODIS ENHANCED SST COMPOSITE PRODUCT.) SCA CONDITIONS ARE LIKELY TO CONTINUE OVER THE OFFSHORE WATERS TONIGHT YET WILL DEFER TO NEXT SHFIT FOR TIMING. && .FIRE WEATHER...BASED ON EXPECTED RELATIVE HUMIDITY AND WIND TRENDS TODAY...WILL MAINTAIN THE CURRENT RED FLAG WARNING. && .LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...MAIN ISSUES ARE HOW TO HANDLE POSSIBLE RAIN CHANCES BY EARLY NEXT WEEK...AND POSSIBLE FRONT WEDNESDAY. SATURDAY NIGHT THROUGH SUNDAY NIGHT SHOULD BE QUIET BUT COOL...WITH TEMPERATURES BELOW NORMAL FOR SUNDAY. WARM UP BEGINS SUNDAY NIGHT AND CONTINUES AT LEAST UNTIL TUESDAY. MODELS THEN DISAGREE ON HOW FAR SOUTH TO BRING UPPER TROUGH AND CONSEQUENTLY... HOW FAR SOUTH TO BRING THE FRONT ON WEDNESDAY. ISENTROPIC UPGLIDE DEVELOPS OVERNIGHT SUNDAY NIGHT AND CONTINUES MONDAY MORNING...BUT CONDENSATION PRESSURE DEFICITS ARE HIGH SO DO NOT THINK TOO MUCH OF RAIN CHANCES AT THIS TIME. NEXT UPPER TROUGH APPROACHES TUESDAY. ECMWF...WHICH IS DEEPER WITH THE TROUGH...IS BRINGING THE FRONT DOWN ON WEDNESDAY WHILE THE GFS AND CANADIAN...WHICH IS SLOWER AND NOT AS FAR SOUTH WITH TROUGH...GENERALLY KEEPS FRONT TO THE NORTH OF THE CWFA. WILL KEEP THE SLIGHT CHANCE FOR SHOWERS EASTERN 2/3RDS OF AREA FOR TUESDAY DUE TO MOISTURE CONTENT AND POSSIBLE LIFT FROM UPPER TROUGH...AND TUESDAY NIGHT FOR THE POSSIBLE FRONTAL ENTRANCE INTO NORTHWEST PORTIONS OF THE CWFA. AT THIS TIME...BELIEVE THAT THE ECMWF IS TOO FAR SOUTH WITH BOUNDARY...GIVEN THE UPPER LEVEL FETCH...SO WILL MAINTAIN A WARM FORECAST FOR TUESDAY NIGHT AND WEDNESDAY (MORE IN LINE WITH THE GFS) AND ALSO MAINTAIN THE SLIGHT CHANCE FOR RAIN ON WEDNESDAY (PROBABLY TOO CAPPED FOR THUNDER). WITH CONTINUED ONSHORE FLOW AND PLENTIFUL MOISTURE...COULD SEE SOME STREAMER SHOWERS ON WEDNESDAY NIGHT OVER THE NORTHEAST...WITH THUNDER POSSIBLE ON THURSDAY OVER THE SAME AREAS...AND FOLLOW THE GFS MOS MORE FOR TEMPERATURES. THUS...ABOVE NORMAL TEMPERATURES ARE FORECAST AFTER SUNDAY WITH ONLY MINIMAL CHANCES FOR PRECIPITATION THROUGH MID WEEK. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 62 45 55 44 68 / 20 30 50 10 10 VICTORIA 60 43 55 38 67 / 10 20 40 10 10 LAREDO 65 43 57 46 71 / 20 50 30 10 0 ALICE 62 44 54 41 70 / 20 40 50 10 10 ROCKPORT 61 48 55 43 66 / 20 20 50 10 10 COTULLA 66 43 56 40 68 / 10 30 30 10 0 KINGSVILLE 64 45 55 41 69 / 20 40 50 10 10 NAVY CORPUS 62 49 55 49 65 / 20 30 60 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...RED FLAG WARNING FROM 10 AM THIS MORNING TO 6 PM CST THIS EVENING FOR THE FOLLOWING ZONES: ARANSAS...BEE...CALHOUN... DUVAL...GOLIAD...JIM WELLS...KLEBERG...LA SALLE...LIVE OAK...MCMULLEN...NUECES...REFUGIO...SAN PATRICIO... VICTORIA...WEBB. WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR THE FOLLOWING ZONES: ARANSAS...BEE...CALHOUN...DUVAL...GOLIAD...JIM WELLS...KLEBERG...LA SALLE...LIVE OAK...MCMULLEN...NUECES... REFUGIO...SAN PATRICIO...VICTORIA...WEBB. GM...DENSE FOG ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. GALE WARNING UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O'CONNOR. && $$ WC/87...SHORT TERM GW/86...LONG TERM ______________________________________________________________________ KCRP - Reference: ['high.) when considering sst values (sport modis sst composite)...'] 690 FXUS64 KCRP 282146 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 346 PM CST TUE FEB 28 2012 .SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...CONCUR WITH THE GFS THAT AN UPPER LEVEL DISTURBANCE (DEPICTED VIA WATER VAPOR IMAGERY/STREAMLINE DATA) WILL EXIT THE SWRN CONUS AND ENTER THE PLAINS OVERNIGHT. A QUASI-ZONAL UPPER PATTERN EXPECTED WEDNESDAY/WEDNESDAY NIGHT OVER TEXAS. IN RESPONSE TO THE UPPER SYSTEM...A WEAK FRONTAL BOUNDARY IS PROGD BY DETERMINISTIC OUTPUT TO ENTER THE HILL COUNTRY OVERNIGHT THEN STALL OVER THE CWA WED. ISSUED LOW POPS FOR ISOLD SHOWERS FOR THE NERN CWA WEDNESDAY. THE FRONT THEN DISSIPATES OVER THE CWA WEDNESDAY NGT YET MAY TRIGGER ADDITIONAL ISOLD SHOWERS OVER THE NERN CWA. WARM TEMPS ARE EXPECTED AGAIN OVER THE CNTRL/WRN SECTIONS WED AFTN OWING TO PERSISTENCE. OWING TO STRONG WIND EXPECTED ALOFT...DO NOT ANTICIPATE DENSE FOG OVER LAND...DECOUPLING NOTHWITHSTANDING. && .MARINE...IN RESPONSE TO THE FOREGOING UPPER DISTURBANCE... INCREASING ONSHORE FLOW ALOFT EXPECTED OVERNIGHT. ANTICIPATE THAT WARMER SSTS OVER THE OFFSHORE WATERS WILL COMBINE WITH MOMENTUM ALOFT TO GENERATE NEAR 20KT WIND OVER THE OFFSHORE WATERS TNGT (VERTICAL MIXING WILL BE LIMITED WHICH EXPLAINS 20KT FCST RATHER THAN 25-30KT SINCE 925MB WIND EXPECTED TO EXCEED 35KT)...GENERALLY CONSISTENT WITH THE NAM/GFS (LOCAL WRF SFC WIND SEEMS A LITTLE HIGH.) WHEN CONSIDERING SST VALUES (SPORT MODIS SST COMPOSITE)... SFC DEW POINTS EXPECTED OVER THE COASTAL WATERS...AND WIND DIRECTIONS...EXPECT SEA FOG TO DEVELOP AGAIN OVERNIGHT. ANTICIPATE THAT DENSE SEA FOG WILL REMAIN GENERALLY NORTH OF PORT ARANSAS AS WIND MAY PARALLEL THE SRN COAST. && .LONG TERM (THURSDAY THROUGH TUESDAY)...SURFACE LOW PRESSURE WILL DEEPEN ON THE LEE SIDE OF THE ROCKIES AHEAD OF THE NEXT MID/UPPER LEVEL TROUGH TO SWING ACROSS THE CENTRAL PLAINS. THIS WILL CAUSE ONSHORE FLOW TO PERSIST ACROSS THE REGION THURSDAY THROUGH FRIDAY. IN ADDITION...850MB TEMPS WILL ONCE AGAIN BE VERY WARM DUE TO SOUTH/SOUTHWESTERLY FLOW. AS A RESULT...TEMPERATURES WILL BE WELL ABOVE SEASONAL AVERAGES TO ROUND OUT THE WEEK. LOW LEVEL MOISTURE WILL KEEP A SLIGHT CHANCE OF SHOWERS AND ONGOING SEA FOG FOR THURSDAY NIGHT INTO SATURDAY MORNING AHEAD OF OUR NEXT FRONTAL PASSAGE. AS THE AFOREMENTIONED SURFACE LOW AND MID/UPPER LEVEL SYSTEM EJECT EASTWARD...A STRONG COLD FRONT WILL BE PUSHED INTO SOUTH TEXAS SOMETIME EARLY SATURDAY MORNING. MODELS GENERALLY PLACE THE FRONT THROUGH THE REGION BETWEEN 06-12Z SATURDAY. WILL MAINTAIN A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE EAST ALONG THE FRONTAL BOUNDARY. HOWEVER A CAP IN PLACE AND LIMITED MOISTURE PROFILE WILL LIMIT OUR CHANCES FOR PRECIPITATION. MUCH COOLER TEMPERATURES AND DRIER CONDITIONS ARE THEN EXPECTED SATURDAY THROUGH EARLY NEXT WEEK AS SURFACE HIGH PRESSURE BUILDS INTO THE REGION. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 66 79 65 80 67 / 10 10 10 20 10 VICTORIA 65 76 64 77 65 / 20 20 20 20 10 LAREDO 68 84 65 86 67 / 10 10 10 10 10 ALICE 66 83 65 83 67 / 10 10 10 20 10 ROCKPORT 66 72 65 73 64 / 10 20 20 20 10 COTULLA 64 81 62 85 63 / 10 10 10 10 10 KINGSVILLE 67 83 66 83 67 / 10 10 10 20 10 NAVY CORPUS 66 73 65 76 67 / 10 10 10 20 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 6 AM CST WEDNESDAY FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 9 PM CST THIS EVENING FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM. DENSE FOG ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM CST WEDNESDAY FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O'CONNOR...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM. && $$ WC/87...SHORT TERM RG/82...LONG TERM ______________________________________________________________________ KCRP - Reference: ['(modis enhanced sst composite.) anticipate at least gusts to gale'] 751 FXUS64 KCRP 192040 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 340 PM CDT THU APR 19 2012 .SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...WATER VAPOR IMAGERY/STREAMLINE DATA DEPICT THE UPPER DISTURBANCE APPROACHING TX/SRN PLAINS FROM THE WEST. SYNOPTIC SCALE LIFT ASSOCIATED WITH THIS DISTURBANCE IS EXPECTED TO AFFECT THE CWA/MSA FRIDAY THEN EXIT FRIDAY NIGHT. THE CORRESPONDING COLD FRONT IS PROGD TO ENTER THE CWA FRIDAY. BOTH THE NAM AND GFS PROG THE FRONT NEAR THE COAST AROUND 00Z SAT. THE COMBINATION OF UPPER/SFC FORCING APPEAR SUFFICIENT FOR CONVECTION. HOWEVER WITH RESPECT TO SURFACE-BASED PARCELS...CIN APPEARS TO BE A LIMITING FACTOR EXCEPT FOR THE NERN SECTIONS (NAM DETERMINISTIC OUTPUT.) THUS WILL ISSUE GREATEST POPS FOR THE NERN SECTIONS. THE NAM/GFS BRN IS PROGD TO DECREASE TOWARD THE SUPERCELLULAR RANGE DRG THE 21Z FRI-00Z SAT PERIOD (ESPECIALLY FOR THE NERN CWA) CONCOMITANT WITH SFC CONVERGENCE ASSOCIATED WITH THE FRONT AND UPPER FORCING. CONCUR WITH SPC REGARDING THE SLIGHT RISK FOR SEVERE OVER THE NERN SECTIONS (DRG THE NARROW 21Z FRI-00Z SAT WINDOW.) WILL INCLUDE SEVERE WORDING IN THE FCST FOR THE VICTORIA CROSSROADS REGION FOR FRIDAY AFTN. EXPECT THE FRONT TO MOVE OFFSHORE AFTER 00Z SAT. THE NAM PROGS ONLY WEAK/MODERATE MSLP RISES AFTER FROPA. THUS DO NOT EXPECT BREEZY CONDITIONS OVER LAND FRIDAY NIGHT. && .MARINE...IN RESPONSE TO THE FOREGOING UPPER DISTURBANCE...EXPECT ONSHORE FLOW TO INCREASE OVER THE COASTAL WATERS OVERNIGHT. THE NAM/LOCAL ARW/GFS SUGGEST BORDERLINE SCA CONDITIONS DRG THE 06Z- 12Z FRIDAY PERIOD. HOWEVER CONFIDENCE IS HIGH ONLY FOR SCEC CONDITIONS FOR THE COASTAL WATERS TNGT. WIND WILL DECREASE SIGNIFICANTLY BY FRIDAY AFTN AS THE COLD FRONT ENTERS THE CWA. AFTER THE FRONT MOVES ACRS THE COASTAL WATERS FRIDAY EVENING... EXPECT STRONG SCA CONDITIONS TO DEVELOP ESPECIALLY WHEN CONSIDERING SIGNIFICANTLY COOLER AIRMASS COMBINED WITH WARM SSTS (MODIS ENHANCED SST COMPOSITE.) ANTICIPATE AT LEAST GUSTS TO GALE FORCE DRG THE 06-12Z SAT PERIOD. && .LONG TERM (SATURDAY THROUGH THURSDAY)...MAIN FORECAST CONCERN IN THE EXTENDED WILL BE STRENGTH OF WINDS ON SATURDAY BEHIND THE FRONT ALONG WITH POSSIBILITY OF FIRE DANGER THREAT. THE UPPER TROUGH WILL BE MOVING ACROSS THE NORTHERN GULF OF MEXICO SATURDAY. MODELS SHOW 925 MB WINDS FROM THE NORTH AT 35 KNOTS AT 12Z SATURDAY FROM THE COASTAL PLAINS AND COASTAL WATERS THAT WILL GRADUALLY DIMINISH DURING THE DAY AS THE GRADIENT RELAXES WITH HIGH PRESSURE BUILDING INTO SOUTH TEXAS. EXPECT BREEZY TO WINDY CONDITIONS OVER THE COASTAL COUNTIES SATURDAY ALONG WITH MUCH DRIER AIR. AFTERNOON RH VALUES EXPECTED TO FALL TO AROUND 20 PERCENT OVER THE BRUSH COUNTRY AND NEAR 30 PERCENT FOR THE COASTAL COUNTIES. EXPECT WINDS TO DIMINISH BY AFTERNOON OVER THE BRUSH COUNTRY SO ONLY EXPECT FIRE WEATHER THREAT TO BECOME ELEVATED WHILE PREVIOUS RAINS FOR THE COASTAL COUNTIES PRECLUDE FIRE WEATHER CONCERNS SATURDAY. SCA CONDITIONS WILL LINGER OVER THE GULF WATERS THROUGH SATURDAY NIGHT WITH WINDS GUSTING TO AROUND GALE FORCE SATURDAY MORNING. FROM SUNDAY INTO THE MIDDLE PART OF NEXT WEEK...SURFACE HIGH PRESSURE RIDGE WILL REMAIN OVER THE WESTERN PART OF THE GULF OF MEXICO WITH ONSHORE FLOW DEVELOPING BY LATE TUESDAY. VERY COOL TEMPERATURES EXPECTED FOR SUNDAY MORNING WITH UPPER 40S POSSIBLE OVER THE EXTREME NORTHERN PORTIONS OF THE FORECAST AREA. AN UPPER LEVEL RIDGE WILL REMAIN TO THE WEST OF THE AREA FROM TUESDAY INTO THURSDAY WITH A GRADUAL WARMING TREND EXPECTED THROUGH THE PERIOD. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 67 81 58 78 53 / 10 40 40 0 0 VICTORIA 63 79 54 76 50 / 10 50 40 0 0 LAREDO 69 91 61 88 58 / 0 20 10 0 0 ALICE 65 84 58 82 52 / 10 30 30 0 0 ROCKPORT 69 78 60 76 57 / 10 40 40 0 0 COTULLA 64 86 56 84 50 / 0 20 10 0 0 KINGSVILLE 66 83 58 80 52 / 10 30 30 0 0 NAVY CORPUS 70 78 62 76 61 / 10 40 40 0 0 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ WC/87...SHORT TERM TT/89...LONG TERM LK/84...LONG TERM ______________________________________________________________________ KCRP - Reference: ['adiabatic with 20-25kt 925mb onshore wind. yet...the 2-km modis sst '] 385 FXUS64 KCRP 082120 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 320 PM CST THU NOV 8 2012 .SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...THE UPPER DISTURBANCE CURRENTLY ENTERING THE WEST COAST (BASED ON WATER VAPOR IMAGERY AND ON NAM/GFS 500MB STREAMLINE OUTPUT/MODEL INITIALIZATIONS) IS EXPECTED TO MOVE SLOWLY EWD ACROSS THE WRN CONUS DURING THE PERIOD (GFS DETERMINISTIC). A SERIES OF WEAK SHORTWAVES MAY MOVE ACRS THE CWA/MSA DRG THE PERIOD. YET NO PCPN EXPECTED OVER THE CWA OWING TO THE SOMEWHAT DRY ATMOSPHERIC COLUMN (MOST RECENT GOES SOUNDER PWAT OUTPUT AND PROXIMITY SOUNDINGS/GFS DETERMINISTIC SOUNDINGS.) GREATER ONSHORE FLOW EXPECTED OVER THE CWA/MSA IN RESPONSE TO THE FOREGOING UPPER DISTURBANCE. ANTICIPATE BREEZY/WINDY CONDITIONS FRIDAY AFTN OVER MUCH OF THE CWA OWING IN PART TO VERTICAL MIXING OF GREATER MOMENTUM. WL USE PERSISTENCE WITH REGARD TO TEMPS WITH SOME ADJUSTMENTS UPWARD OWING TO A SLIGHT INCREASE IN NEAR SFC MSTR DRG THE PERIOD. && .MARINE...THE DETERMINISTIC NAM/LOCAL WRF-ARW/GFS/WAVEWATCH INDICATE THAT SFC WIND WILL APPROACH 20KT OVER THE COASTAL WATERS OVERNIGHT. NOT SURPRISING WHEN CONSIDERING THE NAM 0-1KM LAPSE NOT FAR FROM DRY ADIABATIC WITH 20-25KT 925MB ONSHORE WIND. YET...THE 2-KM MODIS SST COMPOSITE DEPICTS A SIGNIFICANT SST GRADIENT WITH READINGS AROUND 75F OVER THE NEARSHORE WATERS AND AROUND 80F OFFSHORE. THUS WL FCST 15-20KT WIND OVER THE NEARSHORE WATERS AND 20KT OFFSHORE. THUS WL ISSUE A SMALL CRAFT ADVISORY FOR THE OFFSHORE WATERS FOR TONIGHT/EARLY FRIDAY. && .FIRE WEATHER...THE COMBINATION OF FCST WIND/MINIMUM RELATIVE HUMIDITY VALUES/FUEL DRYNESS MAP MAY RESULT IN AN ELEVATED FIRE DANGER CONDITIONS FRIDAY AFTN. YET WL DEFER TO OVERNIGHT SHIFT OWING TO SIGNIFICANT UNCERTAINTY REGARDING WIND. && .LONG TERM (SATURDAY THROUGH WEDNESDAY)...THE FORECAST FOR THIS WEEKEND CONTINUES TO LOOK VERY WARM AND WINDY. THESE CONDITIONS ARE EXPECTED IN ADVANCE OF A STRONG MID/UPPER LEVEL TROUGH FORECAST TO DIG INTO THE NORTHWEST CONS AND THEN APPROACH THE CENTRAL PLAINS THIS WEEKEND. AHEAD OF THIS SYSTEM...SURFACE LOW PRESSURE WILL CONTINUE TO DEEPEN ACROSS THE LEE SIDE OF THE ROCKIES. THUS...THE WINDY CONDITIONS THAT WILL LIKELY BRING SMALL CRAFT ADVISORY CONDITIONS TO THE COASTAL WATERS. IN ADDITION...ABUNDANT LOW LEVEL MOISTURE WILL ADVERT INTO THE REGION AND COULD LEAD TO STREAMER SHOWERS ACROSS THE COASTAL WATERS AND EASTERN INLAND AREAS ON SUNDAY...THEN POSSIBLE THUNDERSTORMS SUNDAY AFTERNOON. AS THE MID/UPPER LEVEL TROUGH SWEEPS THROUGH THE PLAINS SUNDAY NIGHT...A STRONG COLD FRONT WILL PUSH INTO SOUTH TEXAS EARLY MONDAY MORNING AND PUSH OFFSHORE AROUND SUNRISE. AHEAD OF THIS FRONT...MOISTURE WILL POOL ACROSS THE REGION. THIS SHOULD ALLOW SHOWERS AND THUNDERSTORMS TO DEVELOP AHEAD OF AND ALONG THE FRONTAL BOUNDARY. WE STILL CANNOT RULE OUT A STRONG THUNDERSTORM OR TWO GIVEN THE LIFT ASSOCIATED WITH THE FRONT AND UPPER LEVEL JET DYNAMICS ACROSS THE REGION. HOWEVER...AREAS OUT WEST COULD BECOME DRY SLOTTED ALOFT AND SEE THE LEAST AMOUNT OF RAINFALL. BREEZY TO WINDY NORTHERLY WINDS WILL DEVELOP IN WAKE OF THE FRONTAL PASSAGE. WITH THIS...AND A VERY DRY AIR MASS FILTERING INTO THE REGION...ELEVATED TO CRITICAL WILD FIRE WEATHER CONDITIONS WILL BE POSSIBLE MONDAY AND TUESDAY. IN ADDITION...SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED OVER THE COASTAL WATERS DUE TO WINDS AND BUILDING SEAS. TEMPERATURES WILL BE MUCH COOLER FOR ALL OF SOUTH TEXAS WITH AFTERNOON HIGH TEMPERATURES EARLY IN THE WEEK ONLY WARMING INTO THE 60S AND 70S. OVERNIGHT LOW TEMPERATURES WILL DROP INTO THE 40S TUESDAY MORNING...AND MID 40S TO LOWER 50S WEDNESDAY MORNING. EXPECT A SLIGHT WARMING TREND FOR WEDNESDAY AND THURSDAY AHEAD OF POSSIBLY OUR NEXT FRONTAL PASSAGE LATE IN THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 68 84 68 88 72 / 10 10 10 10 10 VICTORIA 62 84 64 84 68 / 10 10 10 10 20 LAREDO 67 90 68 89 70 / 0 10 10 10 10 ALICE 64 88 65 89 69 / 0 10 10 10 10 ROCKPORT 70 80 70 84 73 / 10 10 10 10 20 COTULLA 63 87 64 87 67 / 0 10 10 10 10 KINGSVILLE 66 87 66 88 70 / 10 10 10 10 10 NAVY CORPUS 71 81 72 83 74 / 10 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO NOON CST FRIDAY FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. && $$ WC/87...SHORT TERM RG/82...LONG TERM ______________________________________________________________________ KCRP - Reference: ['the nrn bays/nearshore waters when considering the 2-km modis'] 186 FXUS64 KCRP 091708 AAA AFDCRP AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 1108 AM CST FRI NOV 9 2012 .DISCUSSION...EXTENDED THE SMALL CRAFT ADVISORY (EXCEPT SCEC OVER THE NRN BAYS/NEARSHORE WATERS WHEN CONSIDERING THE 2-KM MODIS COMPOSITE SST PATTERN) THROUGH 00Z SAT OWING TO CURRENT CONDITIONS AND NAM DETERMINISTIC 0-1KM LAPSE RATES OVER THE COASTAL WATERS NOT FAR FROM DRY ADIABATIC COMBINED WITH NAM 20-25KT 925MB ONSHORE WIND. UNSURE WHETHER THE WIND ADVISORY OVER THE SRN CWA WL VERIFY...YET STILL POSSIBLE GIVEN 25KT SUSTAINED 925MB WIND (NAM DETERMINISTIC) COUPLED WITH VERTICAL MIXING. && .PREV DISCUSSION... /ISSUED 459 AM CST FRI NOV 9 2012/ DISCUSSION...SEE AVIATION SECTION BELOW FOR THE 12Z TAF'S. AVIATION...VFR CONDITIONS ARE EXPECTED THROUGH TODAY AND INTO THE EVENING. MVFR CIGS WILL BE POSSIBLE LATE TONIGHT. MAIN ISSUE WILL BE LLWS THIS MORNING. THE WINDS UP TO AROUND 2K FT ARE EXPECTED TO RANGE FROM AROUND 45 KNOTS OVER LRD TO AROUND 35 KNOTS ACROSS THE EASTERN AREAS. AT THE SFC...WINDS ARE CURRENTLY RANGING FROM 5 TO 12 KNOTS. BY MID MORNING THE LOW LEVEL WINDS WILL MIX TO THE SFC WITH SFC WINDS INCREASING TO 20-25KT GUSTING TO 35KT. SFC WINDS ARE EXPECTED TO RELAX AFTER SUNSET WITH THE POTENTIAL FOR LLWS ONCE AGAIN LATE TONIGHT. PREV DISCUSSION... /ISSUED 332 AM CST FRI NOV 9 2012/ SHORT TERM (TODAY THROUGH SATURDAY)...NEXT COUPLE OF DAYS WILL CONTINUE TO BE WARM AND BREEZY/WINDY. A RIDGE ALOFT WILL SLOWLY SHIFT E TODAY AND SAT AS A POTENT LOW DIGS INTO THE SW U.S. WINDS ACROSS S TX WILL BE STRONGER IN RESPONSE TO THIS UPPER LOW. AM EXPECTING WINDS ACROSS THE SRN CWA TO REACH WIND ADVISORY CRITERIA TODAY AND COULD BE A REPEAT ON SATURDAY. NO PRECIP ANTICIPATED THRU SAT AS MOISTURE WILL BE VERY LIMITED TO THE LOWEST LEVELS. PATCHY LIGHT FOG IS NOT OUT OF THE QUESTION EARLY THIS MORNING OR TONIGHT...HOWEVER A STRONG LLJ WILL SHOULD RESULT IN MORE CLOUDS AND INHIBIT FOG FORMATION. WENT WITH PERSISTENCE FOR TODAY'S AND SAT'S HIGHS. TONIGHT'S LOWS WILL BE WARMER WITH INCREASING DEWPOINTS. MARINE...A MODERATE TO STRONG ONSHORE FLOW CAN BE EXPECTED TODAY THROUGH SATURDAY IN RESPONSE TO A POTENT UPPER LEVEL SYSTEM MOVG TOWARD THE ROCKIES AND TX PANHANDLE. THE STRONGER WINDS ARE GENERALLY ACROSS THE OFFSHORE WATERS BUT SHOULD TRANSITION TO THE SRN NEARSHORE AND SRN BAYS THROUGHOUT THE DAY. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE OFFSHORE WATERS UNTIL NOON AND AN SCA WILL BE IN EFFECT BY 9 AM THROUGH THE AFTERNOON FOR THE NEARSHORE WATERS AND BAYS S OF PORT ARANSAS. THIS PATTERN IS ANTICIPATED TO REPEAT TONIGHT THROUGH SATURDAY. FIRE WEATHER...A STRONG SLY FLOW IS EXPECTED ACROSS S TX TODAY. THE LOWEST MN RH VALUES ARE EXPECTED ACROSS THE BRUSH COUNTRY AND RIO GRANDE PLAINS WITH RH BETWEEN 30-35 PERCENT. THE MN RH...STRONG WINDS AND DRY FUELS WILL LEAD TO AN ELEVATED FIRE DANGER THREAT TODAY ACROSS THE BRUSH COUNTRY AND RIO GRANDE PLAINS...GENERALLY WEST OF HIGHWAY 281. RH VALUES ARE EXPECTED BE NEAR 40 PERCENT E OF HIGHWAY 281 TO AROUND 60 PERCENT ALONG THE IMMEDIATE COAST. LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...ONE LAST WARM AND BREEZY TO WINDY DAY ON SUNDAY AHEAD OF THE COLD FRONT. STREAMER SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WILL OCCUR LATE SATURDAY NIGHT INTO SUNDAY MORNING ACROSS THE GULF WATERS AND NORTHEAST CWA. MODELS AGREE THE UPPER LEVEL TROUGH WILL MOVE THROUGH THE ROCKIES AND INTO THE PLAINS SUNDAY. ASSOCIATED STRONG COLD FRONT IS PROGGED BY BOTH THE ECMWF AND GFS TO SWEEP THROUGH SOUTH TEXAS LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING. MODELS HAVE SLIGHTLY SPED UP THE TIMING OF THE FRONT...AND HAVE FOLLOWED SUIT...WITH THE FRONT NOW ENTERING THE NORTHWEST CWA AROUND MIDNIGHT AND REACHING THE COAST AROUND 3 AM. CAP DOES WEAKEN JUST AHEAD OF THE FRONT...AND ALONG WITH THE COLD FRONT AND LEFT FRONT QUADRANT OF JET STREAK THERE SHOULD BE ENOUGH FORCING TO GENERATE AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS ALONG AND AHEAD OF THE FRONT ACROSS THE EASTERN CWA AND MARINE ZONES. IN ADDITION...CAN NOT COMPLETELY RULE OUT A STRONG THUNDERSTORM OR TWO ACROSS THIS REGION. BUMPED POPS UP SLIGHTLY ALONG AND EAST OF I-37. ACROSS THE FAR WEST CWA...LIMITED MOISTURE AND DRY SLOTTING MAY PREVENT CHANCES FOR PRECIP. PRECIP SHOULD QUICKLY END WEST TO EAST EARLY MONDAY MORNING BEHIND THE FRONT... AND HAVE REMOVED MENTION OF PRECIP FOR MOST OF THE AREA AFTER 12Z (EXCEPT OVER THE MARINE ZONES AND FAR NORTHERN COASTAL BEND). BREEZY TO WINDY CONDITIONS AND DRY AIRMASS BEHIND THE FRONT DURING THE DAY MONDAY COULD LEAD TO ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS. SCA CONDITIONS OVER MARINES ZONES BEHIND THE FRONT. MUCH COOLER POST FRONTAL CONDITIONS EARLY NEXT WEEK. LOWS BACK INTO THE 40S AND 50S TUESDAY AND WEDNESDAY MORNINGS WITH HIGHS ONLY IN THE UPPER 60S AND LOW 70S MONDAY AND MID TO UPPER 60S ON TUESDAY. RETURN FLOW SETS UP WEDNESDAY INTO THURSDAY. PREVIOUS RUN OF THE GFS AND ECMWF HAD BEEN INDICATING ANOTHER UPPER LEVEL TROUGH DIGGING INTO THE DESERT SOUTHWEST AND WEST TEXAS ON THURSDAY...WITH PRECIP CHANCES RETURNING TO SOUTH TEXAS AHEAD OF THE SYSTEM. 00Z GFS IS STILL INDICATING THIS...HOWEVER THE 00Z ECMWF CUTS THE UPPER LEVEL SYSTEM OFF FARTHER WEST ACROSS THE PACIFIC AND SOUTHERN CALIFORNIA AND IS SLOWER CARRYING IT EASTWARD. THE 00Z ECMWF APPEARS TO BE AN OUTLIER AND ENSEMBLE MEAN SOLUTIONS SUPPORT SOMETHING CLOSER TO THE 00Z GFS. SO FOR NOW WILL INDICATE MOSTLY CLOUDY CONDITIONS AND SLIGHT CHANCE POPS FOR THURSDAY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 87 68 88 72 88 / 10 10 10 20 10 VICTORIA 85 64 84 68 84 / 10 10 10 20 30 LAREDO 90 68 91 71 91 / 10 10 10 10 10 ALICE 89 66 89 70 90 / 10 10 10 10 10 ROCKPORT 81 70 84 74 84 / 10 10 10 30 20 COTULLA 87 64 88 68 89 / 10 10 10 10 10 KINGSVILLE 88 67 88 71 89 / 10 10 10 10 10 NAVY CORPUS 83 72 83 74 84 / 10 10 10 20 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR THE FOLLOWING ZONES: DUVAL...JIM WELLS...KLEBERG...NUECES...SAN PATRICIO...WEBB. GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. && $$ WC/87...SHORT TERM ______________________________________________________________________ KCRP - Reference: ['waters per 2-km modis composite sst combined with caa.)'] 744 FXUS64 KCRP 102136 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 336 PM CST SAT NOV 10 2012 .SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...CONCUR WITH THE GFS/NAM/ECMWF DETERMINISTIC THAT THE STRONG UPPER DISTURBANCE... CURRENTLY OVER THE WRN CONUS (STREAMLINE DATA/WATER VAPOR IMAGERY)...TO ENTER THE PLAINS SUNDAY. THE BULK OF THE ASSOCIATED DYNAMICS IS PROGD TO REMAIN NORTH OF THE CWA/MSA. YET...UPPER JET DYNAMICS IS EXPECTED TO MOVE OVER THE REGION BY SUNDAY. CONCUR WITH THE FOREGOING DETERMINISTIC OUTPUT THAT THE CORRESPONDING COLD FRONT WILL MOVE ACRS THE CWA SUNDAY NIGHT THEN OFFSHORE. LOW CIN AND LIMITED INSTABILITY WITH CAPES BELOW 1000J/KG SUNDAY MORNING RESTRICTED TO THE NERN CWA SHOULD CONTRIBUTE TO ISOLD SHOWER ACTIVTIY THERE. INCREASING MSTR CONVERGENCE IN ADVANCE OF THE COLD FRONT AND INCREASING JET DYNAMICS WILL RESULT IN AN INCREASE IN THE COVERAGE/INTENSITY OF CONVECTION YET CONFINED PRIMARILY TO THE ERN 2/3RDS OF THE CWA. NAM BRN VALUES IN THE SUPERCELLULAR RANGE SUNDAY AFTN/NGT IN ADVANCE OF THE FRONT SUGGEST THE POSSIBILITY FOR AT LEAST STRONG STORMS DRG THAT TIME PRIMARILY OVR THE ERN CWA. && .MARINE...EXPECT PREDOMINATE SCA OVER THE COASTAL WATERS OVERNIGHT THROUGH AT LEAST MID MORNING SUNDAY BEFORE WIND CONDITIONS IMPROVE FROM WEST TO EAST. HOWEVER...AFTER THE FROPA AFTER 06Z MONDAY... SCA CONDITIONS WILL RESUME...CONSISTENT WITH DETERMINISTIC OUTPUT (AND ALSO WHEN CONSIDERING 80F SST VALUES OVER THE OFFSHORE WATERS PER 2-KM MODIS COMPOSITE SST COMBINED WITH CAA.) && .LONG TERM (MONDAY THROUGH SATURDAY)...ONLY CONVECTION MONDAY MORNING...IF ANY...WILL BE WELL OFFSHORE...AS MUCH COOLER AND DRIER AIR MOVES INTO THE REGION. HOWEVER...A SHORT-WAVE TROUGH WILL MOVE TOWARD SOUTH TEXAS ON TUESDAY. ECMWF AND CANADIAN SHOW A MORE POTENT WAVE (AND ASSOCIATED Q-VECTOR CONVERGENCE)...WHILE GFS AND NAM ARE WEAKER. MEAN 1000-500MB MOISTURE FIELDS ARE 50 PERCENT OR HIGHER OVER THE SOUTHEASTERN CWFA. HAVE DECIDED TO ADD SOME LIGHT RAIN FOR TUESDAY AFTERNOON AND EVENING OVER THE SOUTHEASTERN PORTIONS OF THE CWFA. AFTER THAT...SHOULD BE DRY AS WEAK WAVES STAY NORTH OF THE AREA AND UPPER PATTERN IS RATHER ZONAL. MOISTURE COMES BACK ENOUGH LATE IN THE PERIOD WHERE EASTERN PORTIONS OF SOUTH TEXAS COULD SEE SOME CONVECTION BY FRIDAY AS PWATS INCREASE TO AROUND 1.5 INCHES AND SOME COASTAL SHOWERS COULD MOVE ONSHORE. FOR NOW...ONLY INCLUDED THE GULF WATERS AND THE NORTHEASTERN COASTAL AREAS. OTHER THAN THAT...MUCH COOLER MONDAY...CONTINUED COOL TUESDAY...THEN A GRADUAL WARM UP STARTING MID WEEK. SHOULD SEE ABOVE NORMAL TEMPERATURES BY FRIDAY. BREEZY TO WINDY MONDAY...LESS WIND TUESDAY WITH ONSHORE (EAST TO SOUTHEAST) FLOW NOT OCCURRING TIL THURSDAY. ELEVATED FIRE WEATHER CONCERNS BEHIND FRONT MONDAY...AND SMALL CRAFT ADVISORIES LIKELY TO BE CONTINUED. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 69 83 59 74 52 / 10 20 50 0 0 VICTORIA 67 83 54 72 41 / 10 30 60 0 0 LAREDO 70 88 54 73 51 / 10 10 10 0 0 ALICE 68 85 57 74 47 / 10 20 40 0 0 ROCKPORT 72 81 59 75 52 / 10 30 50 0 0 COTULLA 65 86 50 70 46 / 10 10 10 0 0 KINGSVILLE 68 84 59 73 51 / 10 20 50 0 0 NAVY CORPUS 72 81 62 74 56 / 10 20 50 0 0 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING ZONES: KLEBERG...NUECES. GM...SMALL CRAFT ADVISORY UNTIL NOON CST SUNDAY FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 8 PM CST THIS EVENING FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O'CONNOR. SMALL CRAFT ADVISORY UNTIL 9 AM CST SUNDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM. && $$ WC/87...SHORT TERM GW/86...LONG TERM ______________________________________________________________________ KCRP - Reference: ['output/nam 0-1km lapse rates combined with 925mb wind/2-km modis'] 500 FXUS64 KCRP 160318 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 918 PM CST THU NOV 15 2012 .DISCUSSION...EXPECT THE SFC RIDGE TO BE REINFORCED SOMEWHAT OVER THE CWA/MSA OVERNIGHT/FRIDAY IN RESPONSE TO THE UPPER DISTURBANCE MOVING ACRS THE PLAINS. DECIDED TO UPGRADE TO SCEC CONDITIONS FOR THE COASTAL WATERS BASED ON NAM/GFS/LOCAL ARW DETERMINISTIC OUTPUT/NAM 0-1KM LAPSE RATES COMBINED WITH 925MB WIND/2-KM MODIS SST COMPOSITE. NAM/GFS 300K ISENTROPIC LIFT/CONDENSATION PRESSURE DEFICITS/NAM SOUNDINGS SUGGEST THAT ANY SIGNIFICANT STRATIFORM RAINFALL WL LIKELY BE CONFINED TO THE SRN CWA/MSA AND THUS WL MAINTAIN THE CURRENT PCPN FCST. && .PREV DISCUSSION... /ISSUED 536 PM CST THU NOV 15 2012/ DISCUSSION...UPDATED FOR 00Z AVIATION SECTION BELOW. AVIATION...NO MAJOR CHANGES TO THE TERMINAL FORECAST FOR SOUTH TEXAS THIS EVENING. HOWEVER...HAVE ADDED -RA TO KALI AND KCRP BETWEEN 08Z-12Z (GIVE OR TAKE A FEW HOURS). WITH THE EXCEPTION OF KLRD...MOST LOCATION SHOULD CONTINUE AT VFR LEVELS THROUGH 06Z BEFORE CLOUD DECK LOWERS SOME. FOR KLRD...LIGHT RAIN AND MVFR CIGS ARE MORE LIKELY AND HAVE THAT AS PREVAILING AFTER 06Z. WITH ALL THAT SAID...GENERALLY LIGHT EAST/NORTHEAST WINDS WILL PERSIST THROUGH THE FORECAST PERIOD. CLOUDS LIFT AND CHANCES FOR LIGHT RAIN TAPPER OFF AFTER 12Z ACROSS THE EAST THEN ENDING AROUND 15Z OUT WEST. PREV DISCUSSION... /ISSUED 307 PM CST THU NOV 15 2012/ SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...THE STRATUS DECK CONTINUES TO HOLD ON THIS AFTERNOON ACROSS ALL OF SOUTH TEXAS. MOST OF THE AREA WILL KEEP THIS ALL NIGHT...HOWEVER THE VICTORIA AREA WILL BE A CHALLENGE ONCE AGAIN AS THE CLEARING LINE MAY PUSH BACK INTO THAT AREA AS IT DID LAST NIGHT. HAVE TRENDED TOWARD A PARTLY CLOUDY SKY THERE WITH TEMPS DECREASING A BIT...ALTHOUGH NOT AS FAR AS LAST NIGHT. THERE IS DEFINITELY THE POTENTIAL THOUGH THAT THIS AREA CLEARS AND TEMPERATURES DROP INTO THE LOWER 40S. NOT GOING TO GO THAT EXTREME THOUGH. THE SECOND ISSUE WITH THE FORECAST FOR TONIGHT IS THE PRECIP POTENTIAL...MAINLY WEST. PRETTY GOOD UPGLIDE SETS UP ON THE 300K SFC AND EVEN MORE ON THE 295K SFC...THIS BEING BETWEEN 800 AND 900 MB...LINING UP WITH THE MAIN MOISTURE REGION. CURRENTLY THOUGH...DPT DEPRESSIONS WEST ARE STILL AROUND 20 DEGREES...SO WILL NEED TO OVERCOME THIS. WITH SOME EVAPORATIVE COOLING LIKELY IN THE LAYER EXPECT TEMPS TO DROP INTO THE 50S DESPITE THE HEAVY CLOUD COVER. WAS TEMPTED TO INCREASE POPS A BIT AROUND LAREDO...BUT WITH SIGNIFICANT DIFFERENCES IN MODEL GUIDANCE (GFS UNDER 20...NAM 40 TO 50)...AND QPF NUMBERS ONLY EXPECTED AT A FEW HUNDREDTHS AS IT IS...WILL STICK WITH THE 30 POPS SOUTHWEST AT THIS TIME. ISENTROPIC LIFT WEAKENS DURING THE DAY ON FRIDAY...COULD SEE A BIT OF LIGHT RAIN LINGER FRIDAY MORNING...BUT THINK EVERYONE WILL BE DRY BY THE AFTERNOON. CLOUD COVER WILL CONTINUE TO AFFECT TEMPS FRIDAY. DAYTIME HIGHS ON FRIDAY WILL LIKELY BE THE WARMEST IN THE EAST AND NORTHEAST IN THE LOWER 70S WHERE BREAKS IN THE CLOUDS ARE MOST LIKELY. WESTERN AREAS PROBABLY WONT WARM ABOVE THE MID 60S (SIMILAR TO TODAY). BY FRIDAY NIGHT STRATUS DECK SHOULD BE THINNING AND WOULD ALLOW TEMPS TO DECREASE MORE THAN TONIGHT. LONG TERM (SATURDAY THROUGH THURSDAY)...CONFIDENCE LEVEL IN AN EXTENDED PACKAGE OFTEN DECREASES WITH THE INCREASE IN TIME WHEN THE FORECAST ACTUALLY OCCURS. FORECAST CONFIDENCE IS EVEN LOWER NOW...AS MODELS ARE FLIPPING/CHANGING WITH RESPECT TO MOISTURE AND TIMING OR STRENGTH OF UPPER SYSTEMS. SURFACE HIGH FINALLY MOVES EAST SATURDAY AND MOISTURE/ONSHORE FLOW RESUME. DO NOT THINK MUCH FOR RAIN CHANCES THROUGH SUNDAY NIGHT...THEN MODELS ARE SHOWING A JET STREAK IMPACTING AREA LATE MONDAY AND CONTINUING THROUGH TUESDAY (MAY END BY TUESDAY MORNING...BUT SINCE POPS ALREADY THERE WILL MAINTAIN). WEAK UPPER RIDGE OVER AREA TUESDAY NIGHT/WEDNESDAY (NO RAIN EXPECTED WEDNESDAY)...THEN MODELS DIFFER WITH HANDLING OF MOISTURE AND UPPER SYSTEM FOR THURSDAY. ECMWF KEEPS MORE MORE TO THE WEST (WETTER ON 00Z RUN)...GFS VERY WET. FOR NOW...WILL MENTION CHANCE POPS OVER THE EASTERN AREAS AND SLIGHT CHANCE WEST...WITH THE NOTION THAT SUSTAINED ONSHORE FLOW WILL KEEP ENOUGH MOISTURE AROUND FOR SHOWERS/THUNDER ON THURSDAY. HOWEVER...WILL NOT GO AS HIGH AS GUIDANCE IS SHOWING. OTHERWISE...NOT MUCH CHANGE TO THE TEMPERATURE FORECAST...GENERALLY A WARMING TREND THROUGH EARLY NEXT WEEK THEN TEMPERATURES MOVE LITTLE WITH HIGHS NEAR 80 TO MID 80S AND LOWS UPPER 50S TO MID 60S BY MID WEEK. NOT MUCH IN WINDS INITIALLY...THEN WINDS INCREASE A BIT LATE IN THE FORECAST AS SURFACE TROUGH DEEPENS IN RESPONSE TO APPROACHING SHORT-WAVE. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 57 69 51 72 59 / 20 20 10 10 10 VICTORIA 49 69 42 70 46 / 10 10 10 0 10 LAREDO 56 63 55 69 61 / 30 30 10 10 10 ALICE 55 67 48 72 57 / 20 20 10 10 10 ROCKPORT 58 70 55 71 58 / 10 10 10 0 10 COTULLA 54 65 48 67 55 / 10 10 10 10 10 KINGSVILLE 56 67 49 72 57 / 20 20 10 10 10 NAVY CORPUS 60 69 57 70 61 / 10 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ WC/87...SHORT TERM ______________________________________________________________________ KCRP - Reference: ['near 70f sst values over the nearshore waters based on modis 2-km '] 710 FXUS64 KCRP 241031 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 431 AM CST SAT NOV 24 2012 .SHORT TERM (TODAY THROUGH SUNDAY)...WEAK UPGLIDE LEADING TO LIGHT RAIN THIS MORNING OVER THE REGION...WITH ADDITIONAL LINGERING SHOWERS OVER THE OPEN GULF WATERS. ALL THE ACTIVITY SHOULD GRADUALLY DIMINISH BY MID MORNING AS DRIER AIR AND DOWNGLIDE COMMENCE. A LAYER OF MOISTURE TRAPPED IN THE MID LEVELS WILL CONTINUE CLOUD COVERAGE THROUGH MUCH OF THE DAY...SCATTERING OUT THROUGH THE EVENING...PARTICULARLY OVER THE NORTHEASTERN CWA. WITH THE CLOUDS AND CAA...KEPT DAYTIME TEMPERATURES IN THE 60S...NEARING 70 DEGREES ACROSS THE SOUTHERN AND WESTERN AREAS. AS FOR OVERNIGHT LOWS...THE TRAPPED MOISTURE MAY HINDER LOWS FROM DROPPING TOO MUCH OVER THE SOUTHWEST...BUT FORECAST SOUNDINGS SHOW A BETTER POSSIBILITY OF COOLING OVER THE NORTHEAST WHICH SHOULD ALLOW LOWS TO DROP INTO THE MID 40S. DEVELOPING GUSTY NORTHEAST WINDS THIS MORNING SHOULD RELAX THROUGH THE AFTERNOON AS SURFACE HIGH PRESSURE SETTLES INTO THE REGION. GRADUAL ONSHORE FLOW WILL DEVELOP LATE TONIGHT INTO SUNDAY IN RESPONSE TO A DEVELOPING SURFACE LOW ACROSS THE PANHANDLE. SUNDAY HIGHS WILL REACH INTO THE MID 70S OVER MUCH OF THE AREA...TO THE UPPER 70S ACROSS THE WESTERN BRUSH AS SOUTHWEST H85 FLOW DEVELOPS. && .LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...THE DETERMINISTIC GFS AND ECMWF HAVE BEEN CONSISTENT WITH REGARD TO THE DEVELOPMENT/MOVEMENT OF AN UPPER DISTURBANCE ACRS THE PLAINS MONDAY FOLLOWED BY A QUASI-ZONAL/LOW AMPLITUDE UPPER PATTERN (IGNORING THE WEAK UPPER DISTURBANCE THAT APPEARS IN THE EMCWF/GFS THURSDAY OVER THE TX REGION AS THE 500MB HEIGHT ENSEMBLE MEAN BARELY REVEALS IT.) IN ADVANCE OF THE PLAINS SYSTEM...INCREASING ONSHORE FLOW/MSTR EXPECTED SUNDAY NIGHT/MONDAY SUFFICIENT TO PROVIDE FOR NOCTURAL ISOLD SHOWERS OVER THE WATERS SUNDAY NIGHT/EARLY MONDAY AND AFTN ISOLD SHOWERS OVER THE ERN CWA. FURTHER...INCREASING ONSHORE MOMENTUM ALOFT/NEAR DRY ADIABATIC 0-1KM LAPSE RATES MAY CONTRIBUTE TO NEAR SCA CONDITIONS OVER THE COASTAL WATERS SUNDAY NIGHT/EARLY MONDAY. (SCA CONDITIONS PROBABLY CONFINED TO THE OFFSHORE WATERS OWING TO COOLER NEAR 70F SST VALUES OVER THE NEARSHORE WATERS BASED ON MODIS 2-KM SST COMPOSITE.) IN RESPONSE TO THE PLAINS SYSTEM...A FRONTAL BOUNDARY IS PROGD TO MOVE ACRS THE CWA MONDAY NIGHT/EARLY TUESDAY BEFORE MOVING OFFSHORE. MSTR CONVERGENCE/INSTABILITY SHOULD RESULT IN ISOLD/SCT CONVECTION OVER THE ERN CWA/MSA ALONG AND IN ADVANCE OF THE FRONT. AFTER FRONTAL PASSAGE...AT LEAST MODERATE OFFSHORE FLOW IS EXPECTED TUESDAY OVER THE COASTAL WATERS (AT LEAST SCEC WITH SCA CONDITIONS POSSIBLE). AS THE UPPER PATTERN BECOMES QUASI-ZONAL... ONSHORE FLOW IS EXPECTED TO RESUME BY WEDNESDAY AND CONTINUE THROUGH THE REMAINDER OF THE PERIOD. THE GFS CONTINUES TO PROG SOMEWHAT MOIST ATMOSPHERIC CONDITIONS OVER THE REGION BY THURSDAY. ANTICIPATE NOCTURAL AT LEAST ISOLD CONVECTION OVER THE COASTAL WATERS AND DIURNAL ACTIVITY OVER THE CWA THURSDAY/FRIDAY. (ANTICIPATE PREDOMINATELY SHOWERS THURSDAY AND THUNDER FRIDAY AFTN WHEN CONSIDERING GFS CAPE MAGNITUDES.) && .MARINE...NORTHEAST WINDS STARTING TO PICK UP THIS EARLY MORNING...WITH THE INCREASED WINDS EXPECTED TO LAST THROUGH MID MORNING. WILL CONTINUE SMALL CRAFT ADVISORIES FOR THE AREA. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 67 50 77 61 79 / 10 10 10 10 20 VICTORIA 66 45 75 58 80 / 10 10 10 10 20 LAREDO 69 56 79 57 82 / 10 0 10 10 10 ALICE 68 51 79 59 83 / 10 10 10 10 10 ROCKPORT 67 52 74 64 76 / 10 10 10 20 20 COTULLA 68 49 76 56 81 / 10 0 10 10 10 KINGSVILLE 68 50 78 60 83 / 10 10 10 10 20 NAVY CORPUS 67 56 74 64 76 / 10 10 10 20 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O'CONNOR...COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. && $$ CB/85...SHORT TERM WC/87...LONG TERM ______________________________________________________________________ KCRP - Reference: ['68 degrees f /per modis imagery/ and with dewpoints in the upper'] 153 FXUS64 KCRP 252129 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 329 PM CST SUN NOV 25 2012 .SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...BIGGEST IMPACT FROM AREA WEATHER WILL BE FROM CONVECTION MONDAY NIGHT. PERSISTENT CLOUDS TODAY SHOULD MIX OUT THIS EVENING WITH MAINLY CLEAR TO PARTLY CLOUDY SKIES EXPECTED TONIGHT. SW FLOW JUST OFF THE SURFACE MAY AID IN PREVENTING SIGNIFICANT CLOUD DEVELOPMENT TONIGHT. A WEAK WARM FRONT CURRENTLY PUSHING NORTH ACROSS DEEP SOUTH TEXAS AND THE COASTAL WATERS WILL ALLOW FOR MOISTURE INFLUX TO INCREASE OVERNIGHT TONIGHT. DEWPOINTS SHOULD INCREASE INTO THE 60S ACROSS EASTERN HALF OF CWA AND APPROACH 60S ALONG RIO GRANDE. PATCHY FOG WILL BE POSSIBLE ACROSS INLAND LOCATIONS IF SKIES CLEAR OUT ENOUGH AND WINDS REMAIN LIGHT. PROGD SOUNDINGS ARE NOT OVERLY CONDUCIVE FOR SIGNIFICANT FOG DEVELOPMENT SO FOR NOW WILL MAINTAIN PATCHY FOG FOR AFTER MIDNIGHT. HAVE ALSO INTRODUCED PATCHY SEA FOG FOR NORTHERN BAYS AND WATERWAYS AS SHELF WATERS HAVE COOLED TO 66 TO 68 DEGREES F /PER MODIS IMAGERY/ AND WITH DEWPOINTS IN THE UPPER 60S ADVECTING OVER THE WATERS...PATCHY SEA FOG MAY DEVELOP. WIDESPREAD SIGNIFICANT SEA FOG IS NOT CURRENTLY EXPECTED...HOWEVER. SHALLOW ISOLATED SHOWERS MAY AFFECT THE MARINE AREAS TONIGHT BUT MOST LOCATIONS WILL REMAIN DRY. MONDAY WILL BE AN UNSEASONABLY WARM DAY AS WEAK SHORT WAVE RIDGE SKIRTS THROUGH IN THE MID LEVELS AND A SURFACE COLD FRONT MOVES SOUTH ACROSS TEXAS. MOST OF THE DAY SHOULD REMAIN DRY WITH A MIX OF SUN AND CLOUDS /MID AND UPPER LEVEL CLOUDINESS MAY BECOME THICK IN THE AFTERNOON/. WARM H9 TO H8 TEMPS ON MONDAY WILL MIX TO THE SURFACE DURING THE MIDDAY AND AFTERNOON HOURS RESULTING IN MAX TEMPS WARMING INTO THE 80S AND POSSIBLE APPROACHING 90 ACROSS SOME INLAND LOCATIONS IF WE SEE ENOUGH SUNSHINE. A SURFACE TROUGH/QUASIDRYLINE MAY MOVE EAST OUT OF MEXICO DURING THE LATE AFTERNOON HOURS. AN ISOLATED THUNDERSTORM MAY DEVELOP ALONG THIS BOUNDARY ACROSS THE BRUSH COUNTRY...BUT FOR NOW WILL ONLY HAVE SLIGHT CHANCE POPS FOR SAID LOCALE. BY LATE IN THE DAY THE COLD FRONT WILL BE PUSHING INTO SOUTH CENTRAL TEXAS. AT THE SAME TIME DPVA WILL BE INCREASING DUE TO A STRONG VORT MAX IN THE H5 LAYER MOVING EAST AS A S/W TROUGH. H25 LEVEL PLACES CWA IN FAVORABLE EXIT REGION OF A 90 KT JET STREAK LIFTING NORTH. INTERACTION OF THESE FEATURES SHOULD RESULT IN SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE AREA AFTER SUNSET. THE MOST FAVORABLE AREA FOR ACTIVITY CURRENTLY LOOKS TO BE ACROSS EASTERN ZONES WHERE GREATEST INSTABILITY AND SHEAR ARE PROG TO EXIST. HAVE INCREASED POPS NEARLY AREAWIDE FOR MONDAY NIGHT. CAPE VALUES ARE PROG TO BE 2000 TO 2500 J/KG...LIFTED INDICES OF -6 TO -8 AND SUFFICIENT SHEAR VALUES MAY ALLOW FOR STRONG THUNDERSTORMS TO DEVELOP AFTER DARK. HAIL AND STRONG WIND GUSTS WILL BE THE MAIN THREATS WITH AN ISOLATED STORM POSSIBLY BECOMING SEVERE. ACTIVITY SHOULD END FROM NORTH TO SOUTH AFTER MIDNIGHT AS FRONT PUSHES SOUTH. FRONT SHOULD ENTER NORTHERN ZONES AROUND MIDNIGHT AND SOUTHERN ZONES AROUND SUNRISE. ONLY CAVEAT FOR SIGNIFICANT PRECIP WOULD BE IF LOW LEVEL FLOW REMAINS MORE SWRLY RATHER THAN BACKING TO THE SOUTHEAST. && .LONG TERM (TUESDAY THROUGH SATURDAY NIGHT)...THE COLD FRONT WILL REACH THE IMMEDIATE COAST AROUND SUNRISE TUESDAY ENDING MUCH OF THE RAIN CHANCES ACROSS THE TERRESTRIAL AREAS...WITH LINGERING ISOLD TO SCT PRECIPITATION OVER THE ADJACENT OFFSHORE GULF WATERS. CLOUDS SHOULD CLEAR OUT PRETTY QUICKLY TUESDAY AFTERNOON WITH SFC HIGH AND UPPER RIDGE BUILDING INTO THE REGION. HIGHS TUESDAY WILL BE IN THE UPPER 60S NORTH AND STRUGGLING TO REACH THE LOWER 70S SOUTHERN TIER OF THE CWA. RETURN FLOW WILL QUICKLY RE-ESTABLISH LATE WEDNESDAY INTO THURSDAY AS A WARM FRONT MOVES INTO THE REGION...WITH INCREASED SOUTHEAST WINDS AND MOISTURE IN RESPONSE TO THE SURFACE LOW DEVELOPING ACROSS THE CENTRAL PLAINS/TEXAS PANHANDLE. THIS FEATURE IN CONCERT WITH ATTENDING COASTAL TROUGH...WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS EAST OF HIGHWAY 281 THURSDAY...WITH MOISTURE AND SFC CONVERGENCE MUCH LESS PRONOUNCED WEST OF HIGHWAY 281 ON WEST SIDE OF COASTAL TROF. THERE WILL BE SLIGHT CHANCES OF PRECIPITATION FRIDAY AND SATURDAY MAINLY EAST OF HIGHWAY 77 AND OVER THE ADJACENT GULF WATERS WITH LINGERING COASTAL TROF AND ZONAL FLOW ALOFT. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 63 85 60 72 50 / 10 10 50 20 10 VICTORIA 61 84 55 68 43 / 10 10 50 10 10 LAREDO 61 89 59 71 52 / 0 10 10 10 0 ALICE 63 87 59 71 47 / 10 10 50 10 0 ROCKPORT 67 82 60 69 51 / 10 10 60 20 10 COTULLA 58 84 54 69 46 / 0 10 10 10 0 KINGSVILLE 62 86 61 72 50 / 10 10 50 10 10 NAVY CORPUS 67 81 63 71 55 / 10 10 60 20 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ HART/79...SHORT TERM CORDERO/70...LONG TERM ______________________________________________________________________ KCRP - Reference: ['modis sst composite versus 80s expected over land near the coast) '] 810 FXUS64 KCRP 292126 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 326 PM CST THU NOV 29 2012 .SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...DEEPER MOISTURE CONTINUES TO ADVECT INTO SOUTH TEXAS THIS AFTERNOON. AS MID LEVEL WEAKNESS/DISTURBANCE MOVES ACROSS...ISOLATED SHOWERS HAVE DEVELOPED ACROSS THE COASTAL WATERS. ALSO...A CLOUD DECK AROUND 4-5KFT REMAINS ACROSS THE INLAND AREAS AND HAVE KEPT TEMPERATURES DOWN THIS AFTERNOON. DO EXPECT MOISTENING TREND TO CONTINUE AND WILL MAINTAIN A SIGHT CHANCE OF SHOWERS ACROSS THE EAST AND COASTAL WATERS THROUGH FRIDAY. ONCE THE 500MB DISTURBANCES PULLS AWAY FROM THE REGION...A SLIGHTLY DRIER AIR MASS ALOFT MOVES ACROSS SOUTH TEXAS. THUS...RAINFALL CHANCES REMAIN LIMITED FRIDAY NIGHT. BACK TO TONIGHT...THERE WILL BE POSSIBLE PATCHY FOG ACROSS INLAND AREAS WITH THE INCREASING DEW POINT TEMPERATURES. OVERNIGHT LOWS WILL NOT COOL AS MUCH TONIGHT GIVEN THE CLOUD COVER IN PLACE. SHOULD SEE A BIT MORE BREAKS IN THE CLOUDS ON FRIDAY AND THUS...A SLIGHTLY WARMER AFTERNOON TEMPERATURES. && .LONG TERM (SATURDAY THROUGH THURSDAY)...GREATER MSTR EXPECTED SATURDAY (AS OPPOSED TO TODAY) MAY RESULT IN ISOLD NOCTURNAL COASTAL AND DIURNAL SEA BREEZE (BAYS/NEARSHORE SST VALUES 68-70F PER 2-KM MODIS SST COMPOSITE VERSUS 80S EXPECTED OVER LAND NEAR THE COAST) CONVECTION SAT. THE GFS/ECMWF PROG A QUASI-ZONAL UPPER PATTERN EXCEPT FOR A DISTURBANCE TO MOVE WEST TO EAST ACRS THE NRN CONUS SUNDAY-WEDNESDAY. THIS SYSTEM IS NOT LIKELY TO FORCE A COLD FRONT INTO TX. HWR...THE ECMWF/GFS PROG A WEAK UPPER DISTURBANCE (SOUTH OF THE MAIN TROUGH) TO MOVE ACRS TX/SRN PLAINS LATE MONDAY/TUESDAY (THIS FEATURE STILL APPEARS IN THE GFS ENSEMBLE MEAN.) YET...THE CORRESPONDING SFC BOUNDARY WL LIKELY STALL NORTH OF THE CWA TUESDAY AFTN (IN CONTRAST TO PREVIOUS DETERMINISTIC OUTPUT.) NEVERTHELESS... GIVEN THE PROXIMITY OF THIS FRONT IN ADDITION TO INCREASING MSTR/INSTABILITY...WL FCST ISOLATED CONVECTION OVER THE CWA/MSA FOR TUESDAY. WL NOT FCST PCPN WED CONSIDERING THE POSSIBILITY OF SIGNIFICANT SUBSIDENCE. WL MAINTAIN DRY CONDITIONS FOR THURSDAY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 63 82 64 83 64 / 20 20 10 20 10 VICTORIA 57 79 60 81 59 / 20 20 20 20 10 LAREDO 63 83 66 83 66 / 10 10 0 10 10 ALICE 61 83 62 85 63 / 10 10 10 20 10 ROCKPORT 64 77 64 79 64 / 20 20 20 20 10 COTULLA 60 82 62 82 62 / 10 10 10 10 10 KINGSVILLE 61 82 62 83 62 / 20 10 10 20 10 NAVY CORPUS 66 77 66 79 65 / 20 20 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ RG/82...SHORT TERM WC/87...LONG TERM ______________________________________________________________________ KCRP - Reference: ['values per 2-km modis sst composite.) anticipate noctural isold'] 166 FXUS64 KCRP 302139 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 339 PM CST FRI NOV 30 2012 .SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...ISOLD SHOWER ACTIVITY ANTICIPATED DRG THE 00-03Z SAT OVER PORTIONS OF THE INLAND CWA OWING TO WEAK SEA BREEZE/LIMITED CIN/SUFFICIENT CAPE/RECENT TREND IN PCPN. CONCUR WITH THE GFS DETERMINISTIC THAT A QUASI- ZONAL UPPER PATTERN (500MB) WILL OCCUR DRG THE PERIOD. THIS WILL CONTRIBUTE TO PERSISTENT ONSHORE FLOW. OVER THE COASTAL WATERS... ANTICIPATE SCEC CONDITIONS OVER THE OFFSHORE COASTAL WATERS OWING TO SIGNIFICANT NAM 0-1KM LAPSE RATES/20KT 925MB WIND. (SCEC NOT EXPECTED OVER THE NEARSHORE WATERS WHEN CONSIDERING COOLER SST VALUES PER 2-KM MODIS SST COMPOSITE.) ANTICIPATE NOCTURAL ISOLD SHOWER ACTIVITY OVER THE COASTAL WATERS/COASTAL COUNTIES TONIGHT (CONSISTENT WITH LOCAL WRF-ARW/GFS AND REASONABLE CONSIDERING PWAT VALUES/NAM CIN AND CAPE PATTERNS.) NAM/GFS TIME-HEIGHT/ SOUNDING/PWAT OUTPUT INDICATE SLIGHTLY DRIER CONDITIONS SAT. YET... WILL MAINTAIN LESS THAN 20 PERCENT CHANCE FOR SHOWER ACTIVITY ALONG THE SEA BREEZE SAT AFTN OVER THE ERN CWA (CONSISTENT WITH GFS OUTPUT.) && .LONG TERM (SUNDAY THROUGH FRIDAY)...AN OVERALL QUIET START TO THE EXTENDED FORECAST AS A WEAK MID/UPPER LEVEL RIDGE REMAINS IN PLACE. AT THE SURFACE...ONSHORE FLOW WILL PERSIST AND BRING SCT/BKN CLOUDS TO THE REGION AND AN INCREASE IN SURFACE MOISTURE. THIS WILL ALSO KEEP TEMPERATURES ABOVE AVERAGE WITH AFTERNOON TEMPERATURES REACHING THE 80S FOR MOST INLAND LOCATIONS. THE FORECAST MODELS CONTINUE TO DIFFER ON THE STRENGTH/POSITION OF MID/UPPER LEVEL TROUGH EXPECTED TO MOVE THROUGH THE PLAINS AND GREAT LAKES REGION EARLY IN THE WEEK. THE CANADIAN IS THE STRONGEST WITH A COLD FRONT PUSHING THROUGH SOUTH TEXAS TUESDAY NIGHT. WHILE THE ECMWF/GFS ARE LESS AGGRESSIVE AND ONLY BRING A WEAK BOUNDARY INTO SOUTH TEXAS. WILL FOLLOW THE LATTER SOLUTIONS AND BRING JUST A WEAK FRONT INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY. THERE WOULD BE A SLIGHT CHANCE OF CONVECTION ALONG THIS BOUNDARY AS MOISTURE POOLS AHEAD OF IT EARLY IN THE WEEK. WILL ONLY BUMP TEMPERATURES DOWN A FEW DEGREES WEDNESDAY WITH ONSHORE FLOW BACK FOR THURSDAY. COULD SEE OUR NEXT FRONT TOWARD THE END OF THE FORECAST PERIOD FRIDAY NIGHT/EARLY SATURDAY MORNING. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 67 81 65 83 63 / 10 10 10 10 10 VICTORIA 63 79 60 82 59 / 20 10 10 10 10 LAREDO 67 84 66 83 64 / 10 10 10 10 10 ALICE 66 84 63 85 60 / 20 10 10 10 10 ROCKPORT 66 77 66 80 64 / 20 10 10 10 10 COTULLA 63 82 63 82 60 / 10 10 10 10 10 KINGSVILLE 66 83 63 84 60 / 20 10 10 10 10 NAVY CORPUS 68 77 68 78 65 / 10 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ WC/87...SHORT TERM RG/82...LONG TERM ______________________________________________________________________ KCRP - Reference: ['.marine...nam 0-1km lapse rates/925mb wind/modis 2-km sst composite '] 449 FXUS64 KCRP 012151 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 351 PM CST SAT DEC 1 2012 .SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...ISOLD SHOWER ACTIVITY ALONG THE WEAK SEA BREEZE MAY PERSIST EARLY THIS EVENING OVER MAINLY THE CNTRL CWA. THE UPPER PATTERN OVER THE CONUS WILL BE CHARACTERIZED AS QUASI-ZONAL (WITH NO SIGNIFICANT DISTURBANCES MOVG ACRS THE TX REGION.) THIS WILL ALLOW FOR PERSISTENT ONSHORE FLOW OVER THE CWA/MSA (IN RESPONSE TO THE DEVELOPING TROUGH TO THE LEE OF THE ROCKIES.) ANTICIPATE PATCHY/AREAS OF FOG OVERNIGHT WHEN CONSIDERING THE NAM SOUNDINGS. DETERMINISTIC NAM/GFS SUGGEST DRIER CONDITIONS SUNDAY AND THUS WL NOT INTRODUCE PCPN. HWR...GREATER MSTR EXPECTED TO ADVECT OVER THE MSA SUNDAY NIGHT SUFFICIENT TO ALLOW FOR AT LEAST ISOLD NOCTURAL SHOWERS OVER THE COASTAL WATERS AFTER 06Z MONDAY. ANTICIPATE AT LEAST PATCHY FOG SUNDAY NIGHT OVER THE CWA. && .MARINE...NAM 0-1KM LAPSE RATES/925MB WIND/MODIS 2-KM SST COMPOSITE SUGGEST THAT SFC WIND COULD APPROACH SCA OVER THE OFFSHORE WATERS OVERNIGHT. YET WILL RESTRICT TO SCEC OWING TO UNCERTAINTY/ SURROUNDING OFFICES. && .LONG TERM (MONDAY THROUGH FRIDAY)...ATMOSPHERIC MOISTURE CONTINUES TO REMAIN BEST CONFINED OVER THE EASTERN HALF OF THE CWA INCLUDING THE GULF WATERS. DECENT LOW LEVEL LAPSE RATES AND MOISTURE CONVERGENCE SHOULD ALLOW FOR STREAMER SHOWERS TO CONTINUE OVER THE GULF WATERS...POSSIBLY REACHING INTO THE NORTHEASTERN COASTAL BEND COUNTIES. PATCHY FOG THAT MORNING WILL ALSO BE POSSIBLE. A S/SW FLOW AT H85 WILL CONTINUE TO BRING DRIER AND WARMER AIR TO THE REGION ALLOWING FOR TEMPERATURES TO ONCE AGAIN REACH ABOVE SEASONAL NORMALS. DID ADD IN AN ADDITIONAL NIGHT FOR PATCHY FOG FOR TUESDAY NIGHT AS MOISTURE REMAINS CONFINED AT THE SURFACE WITH LIGHT SURFACE WINDS. MODELS CONTINUE TO PROG A FRONTAL BOUNDARY TO REACH THE AREA LATE TUESDAY INTO WEDNESDAY BEFORE WASHING OUT. WITH MOISTURE DEPTH LIMITED TO THE SURFACE...AM ONLY EXPECTING ISOLATED SHOWERS TO DEVELOP...WITH MOST DEVELOPMENT ESPECIALLY ALONG THE IMMEDIATE FRONTAL BOUNDARY. A BRIEF NORTHERLY FLOW WILL DEVELOP IN WAKE OF THE FRONT BEFORE SHIFTING BACK OUT OF THE SOUTHEAST WITH SURFACE HIGH QUICKLY PUSHING EAST OF THE REGION. DEVELOPING SURFACE LOW OVER THE CENTRAL PLAINS WILL ATTRIBUTE TO LOW- AND MID-LEVELS WINDS TO STRENGTHEN...BRINGING MOISTURE BACK TO THE REGION FOR THE LATTER HALF OF THE WEEK. MODELS DIVERGE AT THE END OF THE WEEK CONCERNING WITH ANOTHER MID LEVEL TROUGH AND POSSIBLE COLD FRONT. THE PAST RUN FINALLY HAD THE EUROPEAN PICKING UP ON A COLD FRONT OVER THE WEEKEND WHICH IS WHAT PREVIOUS RUNS OF THE GFS HAD BEEN DOING. HOWEVER FOR THE LATEST RUN...THE GFS HAS BACKED OFF ON THE FRONT WHILE THE EUROPEAN CONTINUES TO BRING THE FRONT THROUGH. FOR NOW...WITH BOTH MODELS SHOWING AT A NORTHWESTERLY FLOW IN THE MIDLEVELS WHICH SHOULD BE BETTER FOR PUSHING THE FRONT THROUGH...HAVE LEANED MORE TOWARD THE EUROPEAN FOR THE EXTENDED WITH THE FRONT ENTERING THE REGION SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 65 82 64 83 65 / 10 10 10 10 10 VICTORIA 64 80 61 83 62 / 10 10 10 10 10 LAREDO 69 84 63 85 65 / 10 10 10 10 10 ALICE 64 84 61 84 63 / 10 10 10 10 10 ROCKPORT 66 77 65 77 67 / 10 10 10 10 10 COTULLA 65 83 60 83 61 / 10 10 10 10 10 KINGSVILLE 65 84 63 84 63 / 10 10 10 10 10 NAVY CORPUS 67 77 67 79 66 / 10 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ WC/87...SHORT TERM CB/85...LONG TERM ______________________________________________________________________ KCRP - Reference: ['values (2-km modis sst composite) over the bays/nearshore waters for '] 455 FXUS64 KCRP 032159 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 359 PM CST MON DEC 3 2012 .SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...OVERALL DRY COLUMN OF MOISTURE OVER THE AREA...WITH PWATS LESS THAN 1 INCH...VIA THE GOES SOUNDER IMAGERY AS A S/SW FLOW AT H85 CONTINUES TO DRY OUT THE MIDLEVELS. MOISTURE REMAINS CONFINED AT THE SURFACE WITH DEWPOINTS IN THE 60S. WITH CLEARING SKIES...THE REST OF THE EVENING SHOULD BE QUIET. THE MAIN DISCUSSION FOR TONIGHT WILL BE THE FOG POSSIBILITY. THE SURFACE PRESSURE GRADIENT WEAKENS OVER THE AREA WITH WEAK HIGH PRESSURE JUST TO THE NORTHEAST OF THE AREA AHEAD OF AN APPROACHING COLD FRONT. THE LIGHT WINDS...CLEAR SKIES AND A MOIST SURFACE BOUNDARY WILL LEAD TO AREAS OF FOG TONIGHT...WITH POSSIBLE DENSE FOG ACROSS THE INLAND COASTAL PLAINS. DID ADD IN MENTION OF SEA FOG FOR THE NORTHERN BAYS WERE DEWPOINTS SHOULD REACH WATERS TEMPS SIMILAR AS THIS MORNING. MODELS SHOW A BULK OF MOISTURE TO REMAIN EAST OF THE AREA...OVER THE WATERS...TUESDAY MORNING. AND WITH INSTABILITY AND DECENT MOISTURE CONVERGENCE...AM STILL EXPECTING STREAMER SHOWERS OVER THE WATERS TUESDAY MORNING...PARTICULARLY AREAS EAST OF PORT ARANSAS. DIDBACK OFF ON GOING FURTHER INLAND WITH POPS AS DEEP MOISTURE DOES NOT EXIST UNTIL THE AFTERNOON. PRIOR TO THE AFTERNOON...H85 WINDS CONTINUE TO COME OUT OF THE SOUTHWEST CREATING A CAP. BY THE LATE AFTERNOON...MIDLEVEL WINDS WEAKEN AND SHIFT OUT OF THE NORTH WITH MOISTURE POOLING SOUTHWARD ALONG AND AHEAD OF THE FRONT INCREASING THE PWATS TO NEAR 1.4 INCHES. MODELS ARE IN SOMEWHAT GOOD AGREEMENT WITH BRINGING THE FRONT THROUGH THE LATE AFTERNOON OVER THE CWA...REACHING AND STALLING ACROSS THE NORTHWESTERN CWA AROUND 18Z TUES...AND EXITING THE COAST SHORTLY AFTER 00Z WED. WITH THE CAPPING...THINKING THAT MOST DEVELOPMENT WILL BE ISOLATED...AND AM EXPECTING THE BEST LIFT WILL BE ALONG THE IMMEDIATE FRONT. A NORTHERLY FLOW WILL DEVELOP AFTER THE FRONTAL BOUNDARY WITH SHOWERS ENDING THROUGH THE OVERNIGHT HOURS. && .LONG TERM (WEDNESDAY THROUGH MONDAY)...THE GFS/ECMWF CONTINUE TO PROG A QUASI-ZONAL UPPER PATTERN THROUGH FRIDAY...CONDUCIVE TO PERSISTENT ONSHORE FLOW/INCREASING NEAR SFC MSTR. GFS SOUNDINGS INDICATE THAT SIGNIFICANT NEAR SFC MSTR WL RETURN TO THE CWA/MSA BY EARLY THURSDAY. ANTICIAPTE AT LEAST PATCHY RADIATION FOG OVER THE CWA DRG THE APROXIMATELY 06-14Z PERIOD COMMENCING FRIDAY. IN ADDITION...THE GFS/ECMWF PROG SFC DEW POINTS TO APPROACH/EXCEED SST VALUES (2-KM MODIS SST COMPOSITE) OVER THE BAYS/NEARSHORE WATERS FOR SAT/SUN. WL INTRODUCE PATCHY ADVECTION FOG FOR THE (ESPECIALLY NORTHERN) BAYS/NEARSHORE WATERS FOR SAT/SUN. GFS PWAT VALUES OVER THE CWA INCREASE TO NEAR 1.2IN BY EARLY SUNDAY. THE COMBINATION OF GFS MSTR/CIN/CAPE PATTERNS SUGGEST NOCTURAL ISOLD SHOWERS OVER THE COASTAL WATERS SUNDAY YET NO SIGNIFICANT DIURNAL CONVECTION OVER THE CWA. AFTER FRIDAY...THE DETERMINISTIC SOLNS DIVERGE WITH REGARD TO THE TIMING/PSN OF THE TRANSITION TO A HIGH-AMPLITUDE UPPER PATTERN. THE ECMWF AND CANADIAN ARE FASTER THAN THE GFS WITH REGARD TO THE ASSOCIATED UPPER DISTURBANCE. WL DEFER TO THE ECMWF/CANADIAN WHICH MOVES A COLD FRONT ACRS THE CWA MONDAY. ANTICIPATE CONVECTION ALONG THE FRONT YET RESRICTED TO THE ERN CWA/MSA. FURTHER...FCSTG MUCH COOLER HIGH TEMPS MONDAY THAN THE GFS. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 65 83 61 78 59 / 10 20 20 10 10 VICTORIA 63 81 57 76 56 / 10 30 20 10 10 LAREDO 65 85 63 78 59 / 10 10 20 10 10 ALICE 63 85 60 79 58 / 10 20 20 10 10 ROCKPORT 67 77 61 74 62 / 10 20 20 10 10 COTULLA 63 83 59 76 55 / 10 10 20 10 10 KINGSVILLE 63 84 60 78 59 / 10 20 20 10 10 NAVY CORPUS 70 80 62 73 62 / 10 20 20 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ CB/85...SHORT TERM WC/87...LONG TERM ______________________________________________________________________ KCRP - Reference: ['sst values over the bays/nearshore waters (modis sst composite)'] 052 FXUS64 KCRP 151016 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 416 AM CST SAT DEC 15 2012 .SHORT TERM (TODAY THROUGH SUNDAY)...INCREASING UPPER DYNAMICS EXPECTED OVER THE CWA/MSA DRG THE PERIOD IN RESPONSE TO AN UPPER DISTURBANCE EXPECTED TO APPROACH FROM THE WEST. TODAY...IN RESPONSE TO ANOTHER UPPER SYSTEM CURRENTLY JUST NORTH OF TX...A WEAK FRONTAL BOUNDARY IS EXPECTED TO ENTER SRN TX AND STALL JUST NORTH OF THE CWA BY THIS EVENING. ISOLD/SCT CONVECTION ANTICIPATED THIS AFTN OVER THE ERN CWA/MSA OWING TO INSTABILITY/SUFFICIENT MSTR/PROXIMITY OF THE BOUNDARY. TONIGHT...BASED ON ISENTROPIC LIFT/LOW CONDENSATION PRESSURE DEFICITS AT THE 300K LEVEL (GFS DETERMINISTIC)...WL FCST ISOLD SHOWER ACTIVITY FOR THE ERN CWA/MSA. FURTHER...THE NAM DETERMINISTIC SOUNDINGS SUGGEST SATURATED CONDITIONS IN THE LOWER LEVELS OVER THE ERN CWA. THIS COMBINED WITH LGT SFC WIND MAY RESULT IN FOG. SUNDAY...THE COMBINATION OF INCREASING DYNAMICS/INSTABILITY/MSTR SUGGESTS ISOLD/SCT CONVECTION YET CONFINED TO THE ERN CWA/MSA. NAM DETERMINISTIC SOUNDINGS SUGGEST THAT SOME STORMS COULD BECOME STRONG/SEVERE SUNDAY AFTN (BASED ON LOW BRN VALUES.) && .MARINE...SCA CONDITIONS THIS MORNING OVER THE OFFSHORE COASTAL WATERS OWING TO SEAS NEAR 7FT. (SFC WIND SHOULD REMAIN IN THE SCEC CATEGORY TODAY.) ISOLD/SCT CONVECTION ANTICIPATED OVER THE WATERS DRG MUCH OF THE PERIOD. NAM DETERMINISTIC DEW POINTS MAY EXCEED SST VALUES OVER THE BAYS/NEARSHORE WATERS (MODIS SST COMPOSITE) SUFFICIENT TO GENERATE AREAS OF SEA FOG TONIGHT/EARLY SUNDAY. YET UNSURE WHETHER VISIBILITIES WILL APPROACH DENSE FOG ADVSY CRITERION. && .LONG TERM (SUNDAY NIGHT THROUGH SATURDAY)...PRECIPITATION CHANCES QUICKLY SHIFT OFFSHORE SUNDAY EVENING AS THE FRONTAL BOUNDARY MOVES FURTHER SOUTHEAST. SLIGHTLY COOLER AND MUCH DRIER AIR FILTERS INTO THE REGION FOR MONDAY INTO TUESDAY. THIS WILL BRING COOLER OVERNIGHT CONDITIONS BOTH MONDAY AND TUESDAY...HOWEVER AFTERNOON HIGH TEMPERATURES WILL BE MILD UNDER MOSTLY SUNNY SKIES. ONSHORE FLOW RETURNS LATE TUESDAY AS SURFACE HIGH PRESSURE SHIFTS EASTWARD. SURFACE LOW WILL THEN DEEPEN ACROSS THE LEE SIDE OF THE ROCKIES AHEAD OF THE NEXT MID/UPPER LEVEL TROUGH TO PUSH INTO THE WEST COAST DURING THE MIDDLE OF THE WEEK. THIS WILL INCREASE SOUTH/SOUTHEAST WINDS AND HELP BRING A WARMING AND MOISTENING TREND ACROSS SOUTH TEXAS...WITH AFTERNOON HIGHS IN THE 80S AREA WIDE ON WEDNESDAY. THE AFOREMENTIONED MID/UPPER LEVEL TROUGH WILL SWEEP ACROSS THE CENTRAL PLAINS AND BRING A STRONGER FRONT INTO SOUTH TEXAS THURSDAY MORNING. HAVE A SLIGHT CHANCE OF CONVECTION MENTIONED ACROSS THE EASTERN AREAS THURSDAY AS ENOUGH RETURN MOISTURE LOOKS POSSIBLE AS THE FRONT PUSHES THROUGH. STRONG OFFSHORE WINDS WILL DEVELOP IN WAKE OF THIS FRONTAL PASSAGE ON THURSDAY. IN ADDITION...MUCH DIRER AND COOLER AIR WILL FILTER DOWN INTO THE REGION FRIDAY AND SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 80 68 82 56 79 / 30 20 30 30 10 VICTORIA 78 64 79 49 75 / 30 30 50 20 10 LAREDO 80 64 81 54 77 / 10 10 10 10 0 ALICE 81 65 83 54 78 / 20 20 30 20 10 ROCKPORT 73 67 76 57 75 / 30 20 40 30 10 COTULLA 78 62 79 48 77 / 20 10 10 10 0 KINGSVILLE 81 65 83 54 78 / 20 20 30 20 10 NAVY CORPUS 74 69 76 60 75 / 30 20 30 30 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. && $$ WC/87...SHORT TERM RG/82...LONG TERM ______________________________________________________________________ KCRP - Reference: ['offshore waters based on 2-km modis sst composite.) expect min temp '] 444 FXUS64 KCRP 161035 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 435 AM CST SUN DEC 16 2012 .SHORT TERM (TODAY THROUGH MONDAY)...STATIONARY BOUNDARY STRETCHED ACROSS PORTIONS OF SOUTH TEXAS THIS MORNING. AHEAD OF THE BOUNDARY...DEEP MOISTURE REMAINS IN PLACE WITH SURFACE DEWPOINT TEMPERATURES IN THE LOWER 70S EAST OF HIGHWAY 281. A 500MB TROUGH EXITING NORTHERN NEW MEXICO WILL MOVE EAST AND BE THE DRIVING FORCE TO FINALLY PUSH THE STALLED BOUNDARY OFFSHORE BY LATE THIS EVENING. AHEAD OF THIS...MID/UPPER LEVEL DISTURBANCE WILL MOVE ACROSS CENTRAL TEXAS. MEANWHILE...AN UPPER LEVEL JET WILL APPROACH THE REGION AND COMBINE WITH THE DEEP MOISTURE TO PRODUCE ISOLATED TO SCATTERED SHOWERS WITH EMBEDDED THUNDERSTORMS. THE BETTER MOISTURE REMAINS OVER THE VICTORIA CROSSROADS WHERE THE HIGHEST CHANCES ARE...HAVE A MAINLY DRY FORECAST WEST OF HIGHWAY 16 WHERE WEST/SOUTHWEST WINDS WILL BRING IN DRIER AIR FIRST. THE THREAT FOR STRONG TO SEVERE STORMS APPEARS LIMITED AS MOISTURE AND BEST UPPER LEVEL DYNAMICS DO NOT APPEAR TO LINE UP JUST RIGHT. WITH THAT SAID...PRECIPITATION CHANCES SHIFT FURTHER SOUTHEAST OUT OVER THE WATERS BY TONIGHT AS DRIER AIR FILTERS IN BEHIND THE FRONTAL BOUNDARY. WEAK NORTHERLY WINDS WILL ALSO DEVELOP AND PERSIST THROUGH MONDAY WITH RAIN CHANCES ENDING FOR ALL OF THE FORECAST AREA. AS SKIES CLEAR MONDAY...AFTERNOON TEMPERATURES WILL BE MILD AND GENERALLY IN THE 70S TO NEAR 80. HOWEVER...OVERNIGHT TEMPERATURES TONIGHT WILL BE NOTICEABLY COOLER. && .LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...THE ECMWF/GFS ARE CONSISTENT WITH AN UPPER LEVEL DISTURBANCE ENTERING THE WEST COAST TUESDAY...MOVING ACRS THE SRN ROCKIES/SWRN CONUS WEDNESDAY...ACRS THE PLAINS WEDNESDAY NIGHT...THEN OVER THE ERN CONUS LATE THURSDAY/ FRIDAY. THIS SYSTEM WILL CONTRIBUTE TO INCREASING ONSHORE MOMENTUM TUESDAY (SCA CONDITIONS ANTICIPATED TUESDAY NIGHT/EARLY WED OVER THE COASTAL WATERS) AND A COLD FRONTAL PASSAGE BY THURSDAY OVER THE CWA/MSA. INCREASING ONSHORE FLOW NOTWITHSTANDING IN ADVANCE OF THE FRONT...MSTR IS EXPECTED TO BE VERY LIMITED (CONSISTENT WITH GFS AND ECMWF DETERMINISTIC PWAT VALUES/SOUNDING PROFILES) AND THUS NO PCPN EXPECTED ALONG THE FRONT. AFTER FRONTAL PASSAGE OVER THE CWA... CRITICAL FIRE WEATHER CONDITIONS MAY OCCUR THURSDAY AFTN...ESP OVER THE ERN CWA. AFTER THE FRONT MOVES OFFSHORE... ANTICIPATE SCA CONDITIONS OVER THE COASTAL WATERS (GFS 1000-500MB 546DAM THICKNESS INTO CNTRL TX BY EARLY THURSDAY/RECENT SST VALUES ABOVE 70F OVER THE OFFSHORE WATERS BASED ON 2-KM MODIS SST COMPOSITE.) EXPECT MIN TEMP READINGS IN THE 30S FRIDAY. A WARMING TREND EXPECTED TO COMMENCE SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 81 60 80 48 79 / 40 20 10 10 0 VICTORIA 79 52 77 43 77 / 60 20 10 10 0 LAREDO 77 54 77 49 80 / 10 0 0 10 0 ALICE 81 58 80 47 81 / 30 10 10 10 0 ROCKPORT 76 60 75 52 72 / 60 20 10 10 0 COTULLA 75 48 76 42 80 / 10 0 0 10 0 KINGSVILLE 81 59 80 49 80 / 30 20 10 10 0 NAVY CORPUS 74 63 75 54 73 / 40 20 10 10 0 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ RG/82...SHORT TERM WC/87...LONG TERM ______________________________________________________________________ KCRP - Reference: ['waters per modis sst composite) adds credence to the 30-35kt soln. '] 029 FXUS64 KCRP 181050 AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 450 AM CST TUE DEC 18 2012 .SHORT TERM (TODAY THROUGH WEDNESDAY)...THE H5 RIDGE WILL EXIT THE REGION TODAY AS THE NEXT MIDLEVEL TROUGH ENTERS THE CENTRAL PLAINS. THIS WILL KICK OFF A SURFACE LOW NEAR THE PANHANDLE WITH WINDS ACROSS SOUTH TEXAS INCREASING THROUGH THE SHORT TERM...PEAKING AROUND 15-20 MPH DURING THE AFTERNOON AND EARLY EVENING HOURS. IN ADDITION...MOISTURE WILL ALSO GRADUALLY INCREASE THROUGH THE PERIOD. HOWEVER FOR TODAY...A DRY AIRMASS REMAINS ALOFT...AND WITH WARM H85 TEMPERATURES AS WELL AS A SOUTHWESTERLY FLOW OFF OF THE SIERRA MADRE...WILL ALLOW FOR DRY CONDITIONS ONCE MORE THIS AFTERNOON. THE QUESTION REMAINS FOR TONIGHT WITH ANY FOG ISSUES. PROFILE SOUNDINGS SHOW AN INCREASE IN MOISTURE AT THE SURFACE WITH GENERALLY DRY AIR ALOFT UNDER MOSTLY CLEAR SKIES EARLY IN THE NIGHT. HOWEVER...THE SOUTHERLY LOW LEVEL JET WILL STRENGTHEN TO 35-40 MPH WITH SOME MIXING MAKING IT TO THE SURFACE OVERNIGHT. AM THINKING PATCHY FOG WILL BE POSSIBLE EARLY...BUT SHOULD CLEAR LATE IN THE NIGHT. MOISTURE DEPTH ALSO BEGINS TO INCREASE THROUGH WEDNESDAY MORNING. WITH STRONG ISENTROPIC UPGLIDE...LIGHT RAIN WILL BE POSSIBLE THROUGH WEDNESDAY MORNING UNDERNEATH THE DEVELOPING CAP. ANY PRECIP SHOULD QUICKLY END BY THE AFTERNOON DUE TO THE CAPPING. ANOTHER BREEZY DAY WILL BE IN STORE FOR WEDNESDAY. AS FOR DAYTIME TEMPERATURES...THE SOUTHWEST FLOW AT H85 WILL ALLOW TEMPERATURES TO REACH AND POSSIBLY EVEN EXCEED RECORD HIGHS FOR TODAY AND TOMORROW. && .MARINE...WITH SOUTHERLY WINDS STRENGTHENING IN RESPONSE TO A DEVELOP SURFACE LOW OVER THE CENTRAL PLAINS...HAVE ISSUED A SMALL CRAFT ADVISORY FOR THE OFFSHORE WATERS BEGINNING LATE THIS EVENING AND CONTINUING INTO WEDNESDAY. && .FIRE WEATHER...WARMER TEMPERATURES TODAY IN COMBINATION WITH THE DRY AIRMASS ALOFT AS WELL AS MODERATE SOUTHERLY FLOW WILL ALLOW FOR AN ELEVATED FIRE DANGER THREAT THIS AFTERNOON...FOR AREAS FROM BEEVILLE TO REFUGIO WESTWARD TO THE RIO GRANDE. && .LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...GFS/ECMWF DETERMINISTIC SOLNS PROG AN UPPER SYSTEM TO MOVE ACRS THE PLAINS/TX WED NGT/EARLY THU. IN RESPONSE...A COLD FRONT IS EXPECTED TO MOVE ACRS THE CWA WEDNESDAY NIGHT/OFFSHORE EARLY THURSDAY. ANTICIPATE LIMITED MSTR IN ADVANCE OF THE FRONT (GFS DETERMINISTIC) AND WILL NOT FCST PCPN (GFS ENSEMBLE MEAN PCPN.) EXPECT AT LEAST SCA CONDITIONS OVER THE COASTAL WATERS IN RESPONSE TO THE FRONT. THE 00Z TUE CYCLE OF THE GFS/NAM/ECMWF PROG 30-35KT/30KT/25KT MAX SFC WIND OVER THE WATERS EARLY THU. THE NAM 40-50KT 925MB WIND/NEAR DRY ADIABATIC LAPSE RATES OVER THE OFFSHORE WATERS (LAPSE RATES NOT UNREASONABLE GIVEN THE AT LEAST 75F SST VALUES OVER THE OFFSHORE WATERS PER MODIS SST COMPOSITE) ADDS CREDENCE TO THE 30-35KT SOLN. YET WILL FCST 25-30KT SUSTAINED WIND BASED ON THE GFS ENSEMBLE MEAN SFC WIND. WIND/RELATIVE HUMIDITY COMBINATIONS SUGGEST THAT A CRITICAL FIRE WEATHER CONDITION MAY OCCUR OVER PORTIONS OF THE REGION THURSDAY AFTN. NEAR FREEZING CONDITIONS ARE PSBL OVR NRN PORTIONS OF THE CWA EARLY FRIDAY OWING TO EXPECTATION OF LIMITED CLOUD COVER/LGT WIND/VERY LOW SFC DEW POINTS. DETERMINISTIC OUTPUT DEPICTS A TRANSITION TO A QUASI-ZONAL/WEAK AMPLITUDE UPPER PATTERN OVER THE CONUS BY SATURDAY...CONDUSIVE TO THE DEVELOPMENT OF RETURN FLOW/WARMING TREND. THE DETERMINISTIC GFS PROG ISENTROPIC LIFT/ DECREASING CONDENSATION PRESSURE DEFICITS OVER THE CWA/MSA DURING THE SATURDAY THROUGH MONDAY PERIOD...SUGGESTIVE OF INCREASING CLOUDINESS...NOT YET PCPN. (THE ECMWF/GFS PROG THE NEXT UPPER SYSTEM TO APPROACH THE PLAINS LATE MONDAY AND MAY CONTRIBUTE TO CONVECTION JUST BEYOND THIS FCST PERIOD.) && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 85 66 86 54 61 / 0 10 10 10 10 VICTORIA 80 61 80 47 59 / 0 10 10 10 10 LAREDO 86 66 92 51 62 / 0 10 10 10 10 ALICE 86 66 87 52 63 / 0 10 10 10 10 ROCKPORT 77 67 78 52 59 / 0 10 10 10 10 COTULLA 86 61 86 45 61 / 0 10 10 10 10 KINGSVILLE 84 67 86 54 63 / 0 10 10 10 10 NAVY CORPUS 78 68 79 55 60 / 0 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO NOON CST WEDNESDAY FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. && $$ CB/85...SHORT TERM WC/87...LONG TERM ______________________________________________________________________ --- Site: KCTP --- KCTP - Reference: ['yesterday. modis 11-3.7um imagery already showing patchy fog'] 567 FXUS61 KCTP 180940 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 540 AM EDT FRI MAY 18 2012 .SYNOPSIS... A NEARLY STATIONARY RIDGE OF HIGH PRESSURE WILL REMAIN OVER PENNSYLVANIA THROUGH THE UPCOMING WEEKEND. A CUT OFF UPPER LOW OVER THE SOUTHEAST CONUS WILL SLOWLY DRIFT NORTHWARD THROUGH PENNSYLVANIA NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A CHILLY MORNING IN PROGRESS...AS DRY HIGH PRESSURE SYSTEM ALLOWING FOR GOOD RADIATIONAL COOLING. THE NORMALLY COLDER VALLEYS HAVE ALREADY DIPPED INTO THE 30S AT 08Z WITH A COUPLE OF HOURS OF COOLING YET TO GO. THE LARGE TEMP DIFF BTWN WATER/AIR WILL LEAD TO FOG IN THE DEEP RIVER VALLEYS OF THE NORTH...MUCH AS OCCURRED YESTERDAY. MODIS 11-3.7UM IMAGERY ALREADY SHOWING PATCHY FOG FORMING AT 0730Z. AFTER THE CHILLY START...ABUNDANT SUNSHINE WILL WARM THINGS UP QUICKLY. MDL 850MB TEMPS SUPPORT HIGHS IN THE 70S. SINKING AIR ASSOC WITH HIGH PRES AT SFC AND ALOFT SHOULD CAUSE APPROACHING CLOUDS OVR THE GRT LKS TO DISSIPATE BEFORE REACHING CENTRAL PA TDY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... ANOTHER CLEAR AND TRANQUIL NIGHT IN STORE TONIGHT WITH HIGH PRES OVR THE STATE. MODIFICATION OF AIR MASS WILL RESULT IN A SOMEWHAT MILDER NIGHT...BUT WIDESPREAD 40S STILL EXPECTED. ENSEMBLE MEAN 850 TEMPS WARM TO ARND 14C SATURDAY...SUPPORTIVE OF MAX TEMPS IN THE L80S IN MOST VALLEY LOCATIONS. ABUNDANT SUNSHINE AGAIN SEEMS LIKELY ALONG WITH LIGHT WINDS UNDER HIGH PRES RIDGE. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... MED RANGE MDL GUIDANCE NOW CONVERGING ON A SIMILAR SOLUTION WITH RESPECT TO CUT OFF UPPER LOW OVER THE SOUTHEAST CONUS. EXPECT THIS SYSTEM TO LIFT NORTH UP THE EAST COAST LATE SUNDAY AND MONDAY. ASSOCIATED MOIST...EASTERLY LL JET AND UPPER LVL DIVERGENCE PRECEDING THE UPPER LOW WILL LIKELY BRING SCT SHOWERS TO CENTRAL PA BEGINNING LATE SUNDAY AND LASTING THROUGH MONDAY. GEFS DATA SHOWING HIGHEST PWATS ACROSS SOUTHEAST PA...WHERE THE BEST CHC OF MEASURABLE RAINFALL IS EXPECTED SUN NITE/MONDAY. OPER AND ENSEMBLE MDL DATA ALL INDICATE THAT AS UPPER LOW OPENS UP AND LIFTS INTO THE CANADIAN MARITIMES...UPSTREAM SHORTWAVE WILL DEEPEN AND CUT OFF OVR THE OHIO VALLEY DURING THE MIDDLE OF NEXT WEEK. ALTHOUGH TIMING AND TRACK OF THIS FEATURE ARE UNCERTAIN AT THIS POINT...ENOUGH SUPPORT IN THE MDL DATA TO MENTION THE CHC OF DIURNALLY ENHANCED SHRA/TSRA TUES-THURS. SUNDAY LIKELY TO BE ANOTHER WARM DAY WITH PLENTY OF SUNSHINE...ACROSS AT LEAST NORTHWEST PA. CLOUDS AND HIGHER HUMIDITY EARLY NEXT WEEK WILL LIKELY RESULT IN SLIGHTLY COOLER DAYTIME TEMPS...BUT WARMER OVERNIGHT TEMPS. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... HIGH PRESSURE OVER THE GREAT LAKES WILL BUILD INTO THE REGION FOR THE WEEKEND...BRINGING A DRY AIR MASS WHICH WILL RESULT IN CLEAR SKIES AND LIGHT WINDS THROUGH FRIDAY. AREAS OF VALLEY FOG WILL FORM ACROSS NRN PENN LATE TONIGHT...AND DISSIPATE BY 13Z FRIDAY. THERE IS A LOW PROBABILITY FOR A FEW HOUR PERIOD OF MVFR/IFR CIGS AND VSBYS IN FOG/STRATUS AFTER 07Z AT KBFD. OUTLOOK... SAT-SUN...NO SIG WX EXPECTED. MON...SCATTERED MVFR CIGS AND VSBYS IN SHOWERS AND ISOLD THUNDERSTORMS. MONDAY NIGHT AND TUE...MORE WIDESPREAD REDUCED CIGS AND VSBYS POSSIBLE IN SHOWERS AND SCTD TSRA AHEAD OF A SLOW MOVING COLD FRONT APPROACHING FROM THE OHIO VALLEY...AND LOW PRESSURE CREEPING SLOWLY NORTH ALONG THE EASTERN SEABOARD. && .CTP WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR PAZ004>006- 010>012-037-041-042. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...FITZGERALD AVIATION...RXR ______________________________________________________________________ KCTP - Reference: ['end the risk of showers by arnd 12z. modis 11-3.7um product'] 427 FXUS61 KCTP 230938 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 538 AM EDT SAT JUN 23 2012 .SYNOPSIS... HIGH PRESSURE OVER THE GREAT LAKES WILL BUILD SOUTHEAST ACROSS PENNSYLVANIA THIS WEEKEND. A STRONG COLD FRONT WILL PUSH THROUGH THE STATE LATE SUNDAY NIGHT OR EARLY MONDAY. AN ANOMALOUS UPPER LEVEL TROUGH WILL BE OVER THE NORTHEASTERN CONUS FOR THE FIRST HALF OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... EARLY AM WATER VAPOR LOOP SHOWING POTENT SHORTWAVE CROSSING LK ERIE. LG SCALE FORCING AHEAD OF THIS FEATURE...COMBINED WITH LINGERING LOW LVL MOISTURE AND MARGINAL INSTABILITY ACROSS THE EASTERN PA...HAS RESULTED IN A LONE SHOWER E OF IPT AT 09Z. A STRAY SHOWER IS STILL POSSIBLE EAST OF THE SUSQ RIVER BTWN 09Z- 11Z. HOWEVER...PASSAGE OF SHORTWAVE AND ARRIVAL OF DRIER AIR WILL END THE RISK OF SHOWERS BY ARND 12Z. MODIS 11-3.7UM PRODUCT SHOWING DENDRITIC PATTERN OF FOG IN THE VALLEYS NORTH OF I-80. ANY VALLEY FOG SHOULD BURN OFF BY 13Z. HIGH PRESSURE AND ASSOC DRY AIR MASS BUILDING IN FROM THE WEST WILL THEN BRING MSUNNY SKIES AND MUCH LESS HUMID WX FOR THE REST OF TODAY. MDL 800MB TEMPS APPROACHING 10C SHOULD TRANSLATE TO MAX TEMPS FROM THE U70S OVR THE ALLEGHENY MTNS...TO THE M80S IN THE SUSQ VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... MCLEAR SKIES...A CALM WIND AND DRY AIR MASS UNDER SFC HIGH WILL ALLOW FOR SIG RAD COOLING TONIGHT WITH MIN TEMPS IN THE 40S IN THE VALLEYS OF THE ALLEGHENIES AND THE 50S ELSEWHERE. THE COOL TEMPS...COMBINED WITH WARM RIVER/STREAM WATER AND A CALM WIND...WILL LIKELY RESULT IN AM FOG IN THE DEEP VALLEYS OF THE ALLEGHENIES. HIGH PRES WILL PASS OFF THE MID ATLANTIC COAST SUNDAY...ALLOWING OF RETURN SW FLOW OF SLIGHTLY WARMER/MORE HUMID AIR TO OVERSPREAD THE REGION. SOME MID LVL CLOUDINESS APPEARS LIKELY...ESP LATE...THE RESULT OF WAA AHEAD OF APPROACHING SHORTWAVE. LG SCALE FORCING AHEAD OF THIS FEATURE...COMBINED WITH DIURNAL HEATING...COULD PRODUCE ISOLD LATE DAY TSRA. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... EXCELLENT AGREEMENT AMONG MED RANGE GUIDANCE...LEADING TO HIGHER THAN NORMAL CONFIDENCE IN THE EXTENDED FCST. ALL DATA INDICATING A STRONG COLD FRONT PASSAGE OCCURS SUN NITE OR EARLY MON AM...ACCOMPANIED BY SCT SHRA/TSRA. IN THE WAKE OF COLD FRONT...ANOMALOUS UPPER TROF WILL SET UP OVR THE NORTHEAST CONUS...BRINGING A PERIOD OF COOL...BUT MAINLY DRY...WX TO CENTRAL PA DURING THE MON-WED TIME FRAME. POOL OF COLD AIR ALOFT WILL RESULT IN STEEP LOWER TROPOSPHERIC LPS RTS DURING THE AFTN...BRINGING THE POTENTIAL OF A FEW PM SHOWERS OVR THE N MTNS THRU MID WEEK. ALL MDL DATA NOW POINTING TOWARD A QUICK WARM UP LATE WEEK...AS UPPER TROF LIFTS OUT...ALLOWING BUILDING HEAT OVR THE MIDWEST TO PUSH TOWARD PA. ECMWF MEAN 850 TEMPS BY FRIDAY CLOSE TO 20C...INDICATING THE POTENTIAL OF HIGHS EXCEEDING 90F. && .AVIATION /09Z SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE NOW SLOWLY BUILDING INTO THE REGION...WILL DOMINATE THE WEATHER SAT INTO SUN. IFR FOG HAS ALREADY DEVELOPED AT LNS /WHERE SIG RAIN FELL FRI EVENING/ AND KBFD. ADDITIONAL PATCHY VALLEY FOG WILL FORM ELSEWHERE ACROSS CENTRAL PA TOWARD SUNRISE...FALLING MAINLY INTO THE MVFR CATEGORY. WINDS WILL BE LIGHT FROM THE NW. FOG DISSIPATES QUICKLY SAT MORNING...WITH A VFR DAY AND GREAT FLYING CONDITIONS IN STORE. WINDS WILL BE FROM THE NW/W AROUND 10 MPH WITH GUSTS TO 14-18MPH. OUTLOOK... SUN...VFR. ISOLD LATE AFT TSTM W LOCAL RESTRICTION POSS NORTH. SUN NIGHT...VFR TO MVFR...WITH SCT SHOWERS/TSTMS BRINGING LOCAL RESTRICTIONS. MON...VFR TO MVFR...WITH SCT SHOWERS/TSTMS BRINGING LOCAL RESTRICTIONS MAINLY N AND E. TUE-WED...PRIMARILY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...ROSS/FITZGERALD AVIATION...RXR ______________________________________________________________________ KCTP - Reference: ['modis 11-3.7um imagery showing a bit of fog in the valleys of the'] 210 FXUS61 KCTP 240943 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 543 AM EDT SUN JUN 24 2012 .SYNOPSIS... A COLD FRONT WILL PUSH SOUTHEAST ACROSS PENNSYLVANIA TONIGHT AND EARLY MONDAY. AN ANOMALOUS UPPER LEVEL TROUGH WILL BE OVER THE NORTHEASTERN CONUS FOR THE FIRST HALF OF NEXT WEEK. AN UPPER LEVEL RIDGE OVER THE MIDWEST WILL BUILD INTO PENNSYLVANIA BY THE END OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MODIS 11-3.7UM IMAGERY SHOWING A BIT OF FOG IN THE VALLEYS OF THE ALLEGHENIES EARLY THIS AM. ANY FOG SHOULD BURN OFF BY ARND 12Z. AS SFC HIGH PRES PASSES OFF THE MID ATLANTIC COAST TODAY...A RETURN SW FLOW OF SLIGHTLY WARMER/MORE HUMID AIR WILL OVERSPREAD THE REGION. INCREASING MID LVL CLOUDINESS APPEARS LIKELY TODAY...ESP THIS AFTN...THE RESULT OF WAA AHEAD OF APPROACHING SHORTWAVE AND COLD FRONT. LG SCALE FORCING AHEAD OF THIS FEATURE...COMBINED WITH DIURNAL HEATING...COULD PRODUCE ISOLD LATE DAY TSRA ACROSS THE SUSQ VALLEY AND WARREN CO. SATL DERIVED PWATS SHOW A RIBBON OF DRIER AIR ACROSS THE CENTRAL MTNS...WHICH MDL DATA SUGGESTS WILL KEEP THE CENTRAL MTNS DRY TODAY. MDL 800MB TEMPS CLOSE TO 11C SHOULD TRANSLATE TO HIGH TEMPS IN THE L/M80S OVER MOST OF THE REGION TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... SPC PLACING THE NW MTNS IN A SLIGHT RISK OF SVR WX THIS EVENING FROM STORMS PRECEDING ARRIVAL OF COLD FRONT. LG SCALE FORCING AHEAD OF APPROACHING TROF SHOULD SUSTAIN TSRA AFTER DARK AS THEY CROSS LK ERIE INTO NW PA. SOME WEAKENING EXPECTED LATE TONIGHT...AS REMNANTS OF STORMS MOVE INTO LESS UNSTABLE ENVIRONMENT OVR THE CENTRAL MTNS. LINGERING SHRA/TSRA ARE POSSIBLE MON AM ACROSS SOUTHEAST PA WITH FROPA...THEN MUCH COOLER/DRIER AIR MASS OVERSPREADS THE STATE BY AFTN. COOL AIR ALOFT SHOULD RESULT IN A FAIR AMT OF CU BY AFTN...ESP ACROSS THE N MTNS. ENSEMBLE MEAN 8H TEMPS SUPPORTIVE OF HIGHS FROM JUST THE M60S OVR THE N MTNS...TO THE U70S ACROSS THE LOWER SUSQ VALLEY. A GUSTY NW WIND WILL MAKE IT FEEL EVEN COOLER. BUFKIT SOUNDINGS INDICATE THERE WILL BE FREQUENT GUSTS BTWN 20-25KTS. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... EXCELLENT AGREEMENT AMONG MED RANGE GUIDANCE...LEADING TO HIGHER THAN NORMAL CONFIDENCE OVER THE NEXT SEVERAL DAYS. ALL DATA INDICATING AN ANOMALOUS UPPER TROF WILL SET UP OVER THE NORTHEAST CONUS...BRINGING A PERIOD OF COOL...BUT MAINLY DRY...WX TO CENTRAL PA THRU MIDWEEK. POOL OF COLD AIR ALOFT WILL RESULT IN STEEP LOWER TROPOSPHERIC LPS RTS DURING TUE AFTN...BRINGING THE POTENTIAL OF A FEW PM SHOWERS OVR THE NE MTNS. MODEL DATA INDICATING A QUICK WARM UP LATE WEEK...AS UPPER TROF LIFTS OUT...ALLOWING BUILDING HEAT OVR THE MIDWEST TO PUSH TOWARD PA. ECMWF MEAN 850 TEMPS BY FRIDAY CLOSE TO 20C...INDICATING THE POTENTIAL OF HIGHS EXCEEDING 90F IN THE VALLEYS. WILL KEEP CHC OF PM TSRA IN THE FCST THU-SAT...AS PA WILL BE WITHIN RING OF FIRE ON PERIPHERY OF LARGE UPPER LVL RIDGE CENTERED OVR THE MISS VALLEY. && .AVIATION /09Z SUNDAY THROUGH THURSDAY/... HIGH PRESSURE WILL REMAIN IN CONTROL OVER CENTRAL PENNSYLVANIA OVERNIGHT...BRINGING LIGHT WINDS AND PRIMARILY VFR CONDITIONS - THOUGH PATCHY MVFR FOG WILL FORM SHORTLY BEFORE SUNRISE. THE HIGH WILL WEAKEN AND MOVE OFF THE COAST LATER TODAY AS A COLD FRONT DROPS ACROSS THE UPPER MIDWEST AND GREAT LAKES - PASSING THROUGH SUNDAY NIGHT AND MONDAY MORNING. VFR CONDS WILL PREVAIL THROUGH THE DAY AND EVENING HOURS ON SUNDAY...OUTSIDE OF LOCALIZED RESTRICTIONS IN VERY ISOLATED TSTMS ACROSS THE HIGHER TERRAIN. CLOUDS WILL BE ON THE INCREASE SUN NIGHT AS THE COLD FRONT DROPS SOUTHEASTWARD...BRINGING SCT SHRA/TSRA INTO THE N AND W AFTER 04Z MON. BUT OUTSIDE OF THE CONVECTION CONDITIONS SHOULD REMAIN VFR. OUTLOOK... SUN NIGHT...VFR TO MVFR...WITH SCT SHRA/TSRA BRINGING LOCAL RESTRICTIONS. MON...VFR...WITH SCT SHRA/TSRA BRINGING LOCAL RESTRICTIONS MAINLY N AND E EARLY. TUE-THU...VFR. && .EQUIPMENT... OIL PUMP ON KCCX PEDESTAL HAS FAILED AND THE PART IS BEING RUSHED IN. AT THIS POINT...RETURN TO SERVICE IS EXPECTED TO BE SUN AFTN. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...FITZGERALD AVIATION...RXR EQUIPMENT... ______________________________________________________________________ KCTP - Reference: ['modis 11-3.7um imagery showing dendritic pattern of valley fog'] 767 FXUS61 KCTP 300943 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 543 AM EDT MON JUL 30 2012 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL BE OVER PENNSYLVANIA TODAY. A SLOW- MOVING UPPER LEVEL TROUGH MOVE EAST ACROSS THE REGION TUESDAY AND WEDNESDAY. ANOTHER HIGH PRESSURE RIDGE WILL BUILD INTO THE STATE LATE THIS WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MODIS 11-3.7UM IMAGERY SHOWING DENDRITIC PATTERN OF VALLEY FOG ACROSS THE ALLEGHENIES EARLY THIS MORNING...THE RESULT OF A CALM WIND AND TEMPS MUCH COOLER THAN THE RIVER/STREAM WATER. ACROSS SOUTHEAST PA...A MOIST SERLY FLOW...COMBINED WITH RADIATIONAL COOLING...IS CAUSING LOW CLOUDS/FOG TO DEVELOP. LATEST MESOSCALE MDL DATA INDICATES THE ALLEGHENY VALLEY FOG WILL BURN OFF BY ARND 13Z. MDL SOUNDINGS SUGGEST THE LOW CLOUDS/FOG ACROSS THE SOUTHEAST COUNTIES WILL LIFT INTO A SCT-BKN CU LYR BY LATE AM. AS HIGH PRES SHIFTS OFF THE NORTHEAST COAST TODAY...RETURN SOUTHERLY FLOW WILL ADVECT HIGHER DEWPTS BACK INTO THE REGION. LG SCALE FORCING AHEAD OF LOW AMPLITUDE H5 SHORTWAVE TROF SWEEPING EWD THRU THE OHIO VALLEY...COMBINED WITH WEAK SSELY LLVL UPSLOPE FLOW AND DIURNAL HEATING...WILL LIKELY RESULT IN SCT SHOWERS AND TSTMS BY LATE AFTN ACROSS THE LAUREL HIGHLANDS/S-CENTRAL MTNS. 00Z MDL QPFS ARE GENERALLY FAVORING THIS AREA INDICATING A RELATIVE MAXIMUM FROM THE CUMBERLAND PLATEAU/WV-MD PNHDLS NWD INTO S-CENTRAL PA. ENS MEAN 8H TEMPS ARE SUPPORTIVE OF HIGH TEMPS TDY IN THE L/M80S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... WILL MAINTAIN A LOW CHC OF SHRA/TSRA TONIGHT...AS REGION REMAINS UNDER AREA OF LG SCALE FORCING AHEAD OF UPPER TROF. ECMWF/GEFS/NAM ALL PLACE AXIS OF HIGHEST PWATS ALONG SPINE OF APPALACHIANS...SO WILL PLACE BEST CHC OF OVERNIGHT RAINFALL THERE. MOIST SSERLY FLOW...COMBINED WITH RAD COOLING...WILL LIKELY RESULT IN A DEVELOPING STRATUS DECK LATE TONIGHT ALONG AND EAST OF THE SPINE OF THE ALLEGHENIES. PERSISTENT SSERLY FLOW SHOULD RESULT IN VERY SLOW CLEARING ON TUESDAY...WITH MOST LOCATIONS BECOMING PTSUNNY BY AFTN. INCREASING FORCING AHEAD OF APPROACHING SHORTWAVE...COMBINED WITH DIURNAL HEATING...WILL RESULT IN INCREASING COVERAGE OF SHRA/TSRA BY TUE AFTN...ESP ACROSS THE WEST. 03Z SREF AND 00Z GEFS BOTH SUPPORT LIKELY POPS BY LATE IN THE DAY ACROSS THE WESTERN COUNTIES. THE EARLY CLOUD COVER SHOULD HOLD TEMPS DOWN ON TUESDAY...WITH MAXES MOSTLY IN THE U70S AND L80S. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... ALL MED RANGE MDL DATA CONTINUES TO INDICATE PASSAGE OF SLOW- MOVING UPPER LVL TROF OCCURS TUES NIGHT AND WED. DEEP SOUTHERLY FLOW AHEAD OF TROF WILL SUPPLY ABUNDANT MOISTURE FOR SHRA/TSRA. HOWEVER...DO EXPECT A OVERALL DECREASE IN CONVECTION TUE NIGHT...THEN DIURNAL HEATING SHOULD CAUSE RE-INTENSIFICATION OF CONVECTION ACROSS CENTRAL/EASTERN PA ON WED. ENSEMBLE MEAN QPF BTWN TUE-WED RUNNING ARND ONE HALF AN INCH ACROSS CENTRAL PA. BEST CHANCE FOR A COMPLETELY DRY DAY NEXT WEEK APPEARS TO BE THURSDAY...AS HIGH PRES RIDGE AND SOMEWHAT DRIER AIR MASS BUILDS OVR THE AREA. GEFS AND ECMWF ENSEMBLE DATA INDICATE A WARMING TREND THU-SAT...AS HIGH PRESSURE SYS PASSES OFF THE E COAST AND 8H TEMPS RISE A BIT ABV NORMAL. RELATIVELY GOOD AGREEMENT AMONG MED RANGE GUIDANCE THAT POTENT SHORTWAVE AND ASSOC COLD FRONT WILL PUSH THRU CENTRAL PA ARND NEXT SUNDAY. DEVELOPING BERMUDA HIGH WILL LIKELY BRING INCREASING HEAT/HUMIDITY/DIURNAL CONVECTION FRI-SUN...CULMINATING IN THE BEST CHC OF RAINFALL WITH PASSAGE OF CDFRONT. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... AN ISOLATED SHOWER WILL BE POSSIBLE IN FAR EASTERN SECTIONS OVERNIGHT...BUT CHANCES ONE WILL HIT A TAF SITE ARE VERY LOW SO DID NOT MENTION. OTHERWISE...VFR CONDITIONS WILL SLIP TO MVFR AS FOG DEVELOPS TOWARD MORNING /IFR POSS IN A FEW DEEPER VALLEYS/. FOG WILL DISSIPATE BY 13-14Z...WITH VFR DAY IN STORE. LOW AMPLITUDE H5 SHORTWAVE TROF APPROACHING FROM OHIO VALLEY... COMBINED WITH WEAK SSELY LLVL UPSLOPE FLOW AND DIURNAL HEATING WILL RESULT IN SCT SHOWERS AND TSTMS THIS AFTN ACROSS THE LAUREL HIGHLANDS/S-CENTRAL MTNS. OUTLOOK... TUE-WED...VFR-MVFR WITH OCNL SHRA AND SCTD TSRA. THU...FOG POSSIBLE EARLY...OTHERWISE VFR. FRI...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...FITZGERALD AVIATION...RXR ______________________________________________________________________ KCTP - Reference: ['early am modis 11-3.7um imagery showing dendritic pattern of fog'] 020 FXUS61 KCTP 230840 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 440 AM EDT THU AUG 23 2012 .SYNOPSIS... THE TROUGH OVER THE EASTERN US WILL WEAKEN AND A RIDGE WILL FORM TO OUR NORTHEAST. A GRADUAL WARM UP FOR THE WEEKEND UNTIL A NORTHERN STREAM WAVE PUSHES A FRONT INTO PENNSYLVANIA MONDAY OR TUESDAY...OUR BEST CHANCE AT RAIN...THE TROUGH WITH THE FRONTAL SYSTEM SHOULD INTERACT WITH THE UPPER TROUGH ASSOCIATED WITH TS ISAAC ABOUT THE MIDDLE OF NEXT WEEK...AND LIKELY KEEP IT AND MOST OF THE MOISTURE TO OUR SOUTH AND EAST. && .NEAR TERM /THROUGH TONIGHT/... EARLY AM MODIS 11-3.7UM IMAGERY SHOWING DENDRITIC PATTERN OF FOG IN THE VALLEYS OF NORTHERN AND CENTRAL PA WHILE A PATCH OF CIRRUS STREAMS NORTHWARD ACROSS SOUTHEAST PA IN ASSOC WITH SHORTWAVE LIFTING UP THE E COAST. VALLEY FOG SHOULD BURN OFF BTWN 12Z-14Z...LEAVING A MSUNNY SKY FOR THE REST OF THE DAY. SFC HIGH PRES OVR THE REGION WILL RESULT IN VERY LGT WINDS. ENS MEAN 850 TEMPS ARND 15C SHOULD SUPPORT HIGH TEMPS BTWN 80-85F. TRANQUIL...SEASONABLE WX WILL CONTINUE TONIGHT WITH PATCHY VALLEY FOG ONCE AGAIN EXPECTED TOWARD DAWN...MAINLY IN THE CLIMATOLOGICALLY FAVORED DEEP RIVER/STREAM VALLEYS NORTH OF I-80. && .SHORT TERM /FRIDAY/... BY FRIDAY...THE UPPER LEVEL TROUGH WILL CONTINUE TO LIFT THROUGH NEWFOUNDLAND BRINGING A ZONAL FLOW THROUGH THE AREA...PROVIDING MOSTLY FAIR WX. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... WEAK HIGH PRESSURE BUILDS IN OVER THE WEEKEND...PROVIDING FAIR WEATHER. AN H5 RIDGE BEGINS TO BUILD OVER EASTERN CANADA AND THE NORTHEASTERN UNITED STATES FAVORING A GRADUAL WARM TREND. WITH SURFACE HIGH PRESSURE...CURRENT MODEL RUNS CONTINUE TO TREND ABOVE SEASONAL AVERAGE TEMPERATURES. WITH SIGNIFICANT HEATING AND POSSIBLE MOIST SOUTHERLY FLOW...AN AFTERNOON SHOWER AND ISOLATED THUNDERSTORM...SATURDAY AND SUNDAY AFTERNOON IS POSSIBLE. THE MAIN FACTOR IS HOW EAST THE MOISTURE ADVECTS. THE MODELS ARE IN ALIGNMENT THROUGH SUNDAY...WHICH IS WHEN THE EC BEGINS TO OUTRUN THE GFS. THE EC MOVES IT'S UPPER LEVEL LOW FARTHER NORTH...WHERE THE GFS KEEPS THE TROUGH EXTENDED THROUGH THE OHIO VALLEY THROUGH TUESDAY. GEFS AND CMCEFS SUGGEST A WAVE IN THE NORTHERN STREAM MONDAY- TUESDAY WHICH WILL DRAG A COLD FRONT INTO THE REGION. MONDAY INTO TUESDAY IS A GOOD CHANCE FOR SOME SHOWER ACTIVITY. THIS FRONTAL SYSTEM AND UPPER WAVE SHOULD INTERACT WITH TC ISAAC IN THE TUES-WED TIME-FRAME. AT THIS TIME THE PW PLUME IS FORECAST TO BE SHUNTED TO OUR SOUTH AND EAST AS WE ARE PROJECTED TO BE NORTH OF THE FRONTAL BOUNDARY...PERHAPS WE WILL BE SAVED BY THE FRONT. THE TROUGHS MERGE AND WE ARE IN A MEAN TROUGH. IMPRESSIVE FEATURES AROUND MID-WEEK WILL INCLUDE THE PW PLUME AND CIRCULATION WITH ISAAC...LIKELY TO REMAIN TO OUR SOUTH...AND A PRETTY IMPRESSIVE 5940M CLOSED 500 HPA HIGH OVER THE SOUTHWESTERN USA. GOING TO BE VERY HOT UNDER THAT RIDGE AND WET IN THE MOISTURE PLUME ASSOCIATED WITH ISAAC. ALAS WE WILL HAVE A HIGH PROBABILITY OF BEING RELATIVELY DRY AND LOCALLY BORING. && .AVIATION /09Z THURSDAY THROUGH MONDAY/... 11-3.9U SATL IMAGERY SHOWS FOG/LOW CLOUDS EXPANDING THRU THE DEEP RIVER/STREAM VALLEYS OF NORTH CENTRAL PA AT 08Z. CONTINUED RADIATIONAL COOLING WILL RESULT IN MAXIMUM EXTENT OF THE FOG BTWN 10Z-11Z. THE RIDGETOP LOCATION AT JST SHOULD PRECLUDE ANY FOG ISSUES THERE AND PATCH OF HIGH LVL CLOUDINESS PASSING OVR THE LOWER SUSQ VALLEY WILL LIKELY PRECLUDE SIG VIS RESTRICTIONS AT MDT/LNS. HOWEVER...A BRIEF DIP TO IFR CONDS REMAINS POSSIBLE AT THE REMAINING CENTRAL PA AIRFIELDS BTWN 09Z-12Z. ANY FOG WILL BURN OFF BTWN 12Z-13Z. WITH HIGH PRESSURE OVR THE REGION...THERE IS A HIGH CONFIDENCE FORECAST OF VFR CONDS AND LGT WINDS FOR THE REST OF THE DAY. A SIMILAR SCENARIO WILL PLAY OUT TONIGHT...WITH PATCHY VALLEY FOG POSSIBLE ARND DAWN. OUTLOOK... FRI-SAT...PATCHY AM FOG POSSIBLE. SUN...SHRA/LOW CIGS POSSIBLE LATE...MAINLY EAST. MON...SHRA/LOW CIGS POSSIBLE EARLY...MAINLY EAST. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...GRUMM NEAR TERM...FITZGERALD SHORT TERM...GRUMM LONG TERM...GRUMM/CERU AVIATION...FITZGERALD ______________________________________________________________________ KCTP - Reference: ['early am modis 11-3.7um imagery showing dentritic pattern of'] 953 FXUS61 KCTP 241012 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 612 AM EDT FRI AUG 24 2012 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL REMAIN OVER PENNSYLVANIA TODAY. AN UPPER LOW OVR THE SOUTHEAST CONUS WILL DRIFT NORTH INTO THE CENTRAL APPALACHIANS OVR THE WEEKEND. A NORTHERN STREAM WAVE AND COLD FRONT WILL LIKELY PUSH THROUGH THE REGION ON TUESDAY. A DEEP TROUGH TO OUR NORTHEAST AND RESULTING NW FLOW SHOULD KEEP ISAAC WELL TO OUR SOUTH THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... EARLY AM MODIS 11-3.7UM IMAGERY SHOWING DENTRITIC PATTERN OF VALLEY FOG ACROSS NORTH CENTRAL PA...WHICH SHOULD BURN OFF BTWN 12Z-14Z. IR SATL TRENDS AND MDL DATA SUGGEST CIRRUS WILL CONTINUE TO STREAM NORTHWARD UP EASTERN SIDE OF UPPER TROF AXIS...AFFECTING THE EASTERN HALF OF PA TODAY. VARYING OPACITY OF HIGH CLOUD SHIELD WILL CAUSE SKIES TO RANGE FROM MCLDY TO MSUNNY TODAY ACROSS THE SE HALF OF THE STATE...WHILE THE NW HALF REMAINS MAINLY SUNNY. SFC RIDGE WILL REMAIN OVR CENTRAL PA...ENSURING DRY WX OVR MOST IF NOT ALL OF THE AREA. AS OCCURRED YESTERDAY...CAN/T COMPLETELY RULE OUT AN ISOLATED PM SHRA/TSRA ACROSS THE SE COUNTIES...WHERE PWATS A BIT HIGHER. HOWEVER...WILL KEEP POPS BLW 10PCT. TODAY SHOULD BE ANOTHER FAIRLY WARM DAY FOR LATE AUGUST. MDL 8H TEMPS ARE SUPPORTIVE OF MAXES IN THE L/M80S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... LGT WIND AND A MCLEAR SKY ACROSS THE W MTNS WILL LIKELY YIELD MORE PATCHY VALLEY FOG ACROSS THE ALLEGHENIES LATE TONIGHT. HOWEVER...BACKING UPPER FLOW AHEAD OF APPROACHING UPPER LOW MAY CAUSE CIRRUS TO WORK WESTWARD ACROSS THE REGION TONIGHT...DAMPENING THE RAD COOLING AND POTENTIAL OF FOG. AS UPPER LOW CREEPS UP THE APPALACHIANS...EXPECT INCREASINGLY MOIST SERLY FLOW TO OVERSPREAD THE STATE FROM THE SOUTH. THE FACE OF 1-2.5SIGMA 850 HPA WINDS IMPLIES INCREASING CLOUDS AND INCREASED CHANCE SHOWERS IN SERN AREAS. TEMP FCST PROBLEMATIC...AS MDLS DIFFER WITH RESPECT TO ARRIVAL OF CLOUD/SHRA. FOR NOW GONE WITH HIGHS BTWN THE M70S-L80S. HOWEVER...COULD EASILY BE SEVERAL DEGREES WARMER OR COOLER. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... GOOD AGREEMENT AMONG MED RANGE GUIDANCE...ALL TRACKING UPPER LOW UP THE APPALACHIANS SAT NIGHT TO NR THE MASON DIXON LINE ON SUNDAY. THIS SCENARIO WILL BRING A GOOD CHANCE OF SHOWERS TO CENTRAL PA SAT NIGHT AND SUNDAY...AS ASSOCIATED MOIST...EASTERLY LL JET LIFTS THRU. LATEST GEFS DATA DRAWS BAND OF LL EASTERLY WIND ANOMALIES AND ASSOC POSITIVE PWAT ANOMALIES INTO SOUTHERN PA SAT NIGHT...THEN THE REST OF THE REGION ON SUNDAY. HAVE TRENDED POPS UPWARD DURING THIS TIME FRAME. OTHER CHANGE TO FCST WAS TO LOWER MAX TEMPS ON SUNDAY DUE TO EXPECTED EASTERLY FLOW...STRATUS AND SHRA. RELATIVELY HIGH CONFIDENCE FCST EARLY NEXT WEEK...AS BULK OF MDL DATA PUSH REMNANTS OF UPPER LOW OFF THE COAST MONDAY...THEN TRACK NORTHERN STREAM SHORTWAVE AND ASSOC COLD FRONT THRU CENTRAL PA ON TUESDAY. SHRA/TSRA COULD ACCOMPANY THE FROPA...THEN DRY WX APPEARS LIKELY FOR WED-THU WHEN ENSEMBLE AND OPER MDL DATA INDICATE STRONG RIDGE AND LOW PWATS OVERSPREADING THE STATE. MOST MODELS...AND THE OFFICIAL HURRICANE CENTER FORECAST...BRING ISAAC INTO THE GULF OF MEXICO EARLY NEXT WEEK. AFTER THAT...THE MODEL SOLUTIONS BEGIN TO DIVERGE. HOWEVER THE BULK OF SOLUTIONS SLOW REMNANTS DOWN AND TRACK THEM INTO THE MISS VALLEY. WHICHEVER TRACK IT EVENTUALLY TAKES...WE/LL HAVE TO KEEP AND EYE ON WHERE THE MOISTURE FROM THIS SYSTEM FINALLY ENDS UP. && .AVIATION /10Z FRIDAY THROUGH TUESDAY/... VALLEY FOG HAS BEGUN TO DEVELOP ACROSS THE AREA. EXPECT RESTRICTIONS AT MOST AIRFIELDS TO MVFR CONDITIONS EARLY THIS MORNING...WITH SOME SPOTTY IFR/LIFR AT KIPT AND KBFD. KLNS MAY ALSO BRIEFLY DIP TO IFR CONTITIONS. OTHERWISE...HIGH PRESSURE WILL CONTROL THE WEATHER INTO THE EARLY PART OF THE WEEKEND...PROVIDING MAINLY VFR CONDITIONS. HOWEVER...FOG IS AGAIN EXPECTED TO DEVELOP TONIGHT WITH MORE MVFR AND SPOTTY IFR CONDITIONS. EASTERLY FLOW MAY BEGIN TO INTRODUCE SOME LOWER STRATUS BUILDING IN FROM THE SOUTHEAST SATURDAY NIGHT INTO SUNDAY. OUTLOOK... SAT...VFR EXCEPT AM VALLEY FOG. SAT NIGHT...SHRA/STRATUS POSS SE...LATE NIGHT FOG NRN VALLEYS. SUN...SHRA/LOW CIGS POSSIBLE...MAINLY EAST. MON...SHRA/LOW CIGS POSSIBLE EARLY...MAINLY EAST. MON NIGHT-TUE...CFRONT APPCHS FM NW. SHRA/TSRA POSS. MAINLY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...GRUMM/FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...GRUMM/FITZGERALD AVIATION...JUNG ______________________________________________________________________ KCTP - Reference: ['early am modis 11-3.7um imagery showing typical dendritic pattern'] 322 FXUS61 KCTP 311026 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 626 AM EDT FRI AUG 31 2012 .SYNOPSIS... A LARGE UPPER LEVEL RIDGE WILL BE OVER THE EAST COAST TODAY. A WEAK COLD FRONT WILL SLIDE SOUTH ACROSS THE STATE TONIGHT BEFORE STALLING OUT NEAR OR JUST TO THE SOUTH OF THE MASON DIXON LINE SATURDAY. THE REMNANTS OF ISAAC WILL LIKELY MERGE WITH A COLD FRONT AND PUSH THROUGH THE REGION EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... EARLY AM MODIS 11-3.7UM IMAGERY SHOWING TYPICAL DENDRITIC PATTERN OF FOG IN THE VALLEYS NORTH OF I-80. THIS FOG WILL BURN OFF BTWN 12Z-14Z. THE PEAK OF THIS BOUT OF LATE SUMMER WARMTH WILL OCCUR TODAY AS THE SFC HIGH DRIFTS OFF TO OUR SOUTHEAST. TIGHTENING LLVL PRESSURE GRADIENT BETWEEN THE HIGH AND APPROACHING COLD FRONT WILL COMBINE WITH DEEP VERTICAL MIXING /UP TO 5-6 KFT AGL/ TO CREATE A GUSTY WESTERLY WIND OF 10-20 KTS FOR THE LATE MORNING AND AFTERNOON HOURS. ALTHOUGH WE/LL SEE AN INCREASE IN DEWPOINTS TO THE MID 50S TO NEAR 60F FRIDAY...THEY SHOULD DECREASE A FEW DEG F DURING THE MIDDAY HOURS AS THE VERTICAL MIXING DEEPENS...AND NEAR TO SLIGHTLY BELOW NORMAL PWAT AIR OF LESS THAN ONE INCH PERSISTS. PLENTY OF SUNSHINE...COMBINED WITH GEFS MEAN 850 MB TEMPS NR 20C /OR PLUS 2-3 STANDARD DEVIATIONS/ WILL SUPPORT MAX TEMPS FROM THE M80S OVER THE HIGHER TERRAIN OF THE ALLEGHENIES...TO ARND 90F ACROSS THE SUSQ VALLEY. THESE READINGS ARE A SOLID +10-15F ABV LATE AUG NORMALS BUT STILL SEVERAL DEGS SHY OF HISTORICAL RECORDS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WEAKENING COLD FRONT APPROACHES FROM THE PA/NY BORDER THIS EVENING. HOWEVER...TIME OF ARRIVAL AFTER SUNSET...COMBINED WITH LIMITED MOISTURE SHOULD SUPPORT NOTHING MORE THAN SOME HIGH BASED...SCT- BKN STRATO CU ACROSS THE NRN TIER THIS EVENING WITH A LONE SPRINKLE POSSIBLE. AS FRONT SLIDES SOUTH ACROSS THE AREA TONIGHT...VERY LITTLE CHANCE OF PRECIP ACROSS THE CENTRAL COUNTIES. HOWEVER...CAN/T RULE OUT A LATE NIGHT SHRA ACROSS EXTREME SW PA...WHERE PWATS PROGGED TO BE MUCH HIGHER. INCREASING DWPTS...A BIT OF CLOUD COVER AND A BREEZE WILL RESULT IN A MILDER NIGHT THAN THOSE RECENTLY WITH LOWS FROM THE M50S N MTNS...TO U60S S TIER. COLD FRONT WILL BECOME STATIONARY SOUTH OF THE MASON-DIXON LINE SATURDAY. MUCH DRIER AIR MASS WORKING IN NORTH OF THIS BOUNDARY SHOULD SUPPLY MOST OF CENTRAL PA WITH MSUNNY AND STILL WARM WX. HOWEVER...THE LAUREL HIGHLANDS WILL LIKELY SEE LINGERING CLOUDS IN VICINITY OF FRONT ALONG WITH THE CHC OF A SHRA OR TSRA. GEFS MEAN 850MB TEMPS ARE SUPPORTIVE OF HIGH TEMPS FROM NEAR 80F OVR THE N MTNS...TO NR 90F IN THE VALLEYS NR THE MASON DIXON LINE. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... BULK OF MED RANGE GUIDANCE DRAW REMNANTS OF ISSAC EASTWARD THRU THE OHIO VALLEY LATE THIS WEEKEND...THEN THRU PA EARLY NEXT WEEK AS IT MERGES WITH COLD FRONT PRESSING SOUTH FROM THE GRT LKS. THIS FRONTAL PASSAGE WILL BRING THE POTENTIAL FOR ENHANCED RAINFALL INTO THE NORTHEAST EARLY NEXT WEEK...WITH TUESDAY APPEARING TO BE THE MOST LIKELY DAY OF FROPA. ENSEMBLE DATA AND ANTECEDENT CONDITIONS CONTINUES TO SUGGEST WIDESPREAD FLOODING IS A LOW PROBABILITY. MUCH OF THE UNCERTAINTY IN THE FCST IS ASSOCIATED WITH SHORTWAVES CROSSING S-CENTRAL CANADA IN THE LOW AMPLITUDE MEAN WESTERLY FLOW ALOFT. THE NCEP GFS/GEFS DATA REMAINS ON THE LEADING EDGE OF THE GUIDANCE ENVELOPE WITH THE PROGRESSION OF HGT FALLS/PCPN THRU THE REGION EARLY NEXT WEEK. WILL CONTINUE TO RELY ON A NEAR EVEN BLEND OF THE GFS/ECMWF/GMOS/HPC GRIDS WHICH FOCUSES THE WINDOW OF OPPORTUNITY FOR ENHANCED RAINFALL/HIGHEST POPS ON TUE. BY NEXT WED-THUR...THERE IS BROAD AGREEMENT IN A DEEPENING UPPER TROUGH TO OUR WEST ACROSS THE GRT LKS/MISS VALLEY. MOIST SW FLOW AHEAD OF THIS FEATURE WILL BRING THE CHC OF SHOWERS LATE WEEK. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... HIGH PRESSURE WILL BRING QUIET WEATHER TO CENTRAL PA INTO SAT NIGHT. CLEAR SKIES WILL PREVAIL OVERNIGHT WITH A LIGHT /YET MOIST/ SOUTHERLY WIND. THIS SHOULD BE ENOUGH TO GENERATE SOME PATCHY MVFR FOG - MAINLY IN THE SUSQ VALLEY AND SOUTHERN MTNS - TOWARD MORNING. A BRIEF PERIOD OF IFR IS POSS IN THE LOWER SUSQ JUST BEFORE SUNRISE. ANY FOG QUICKLY DISSIPATES AFTER SUNRISE ON FRIDAY...LEAVING WIDESPREAD VFR CONDITIONS FOR THE REST OF THE DAY. WINDS DO PICK UP FROM THE WEST BY LATE MORNING...WITH SPEEDS OF 10-15 MPH GUSTING UP TO 25 MPH. OUTLOOK... FRI/FRI NIGHT...NO SIG WX EXPECTED. SAT...AM FOG POSS W MTNS. ISOLD PM TSRA IMPACTS POSS SOUTHWESTERN PENN...NEAR AND TO THE WEST OF KAOO AND KJST. SUN...ISOLD PM TSRA IMPACTS POSS SOUTH. MON AND TUE...SCATTERED SHRA AND ISOLATED AFTERNOON TSRA. PERIODS OF LOW CIGS POSS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...FITZGERALD/STEINBUGL AVIATION...RXR ______________________________________________________________________ KCTP - Reference: ['early am modis 11-3.7um imagery showing dendritic pattern of fog'] 586 FXUS61 KCTP 200958 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 558 AM EDT THU SEP 20 2012 .SYNOPSIS... A DEEPENING UPPER TROUGH OVR THE GRT LKS WILL PUSH A COLD FRONT THROUGH CENTRAL PA LATE SATURDAY. THE UPPER TROUGH WILL ROTATE THROUGH THE REGION SUNDAY...FOLLOWED BY HIGH PRESSURE EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... EARLY AM MODIS 11-3.7UM IMAGERY SHOWING DENDRITIC PATTERN OF FOG IN THE VALLEYS...THE RESULT OF A COOL...CALM MORNING AND RELATIVELY WARM RIVER/STREAM WATERS. LATEST 3KM HRRR SFC RH FIELDS SUGGEST THE MOST PERSISTENT FOG WILL BE UNDER SFC RIDGE AXIS ACROSS THE SUSQ VALLEY...WHERE PATCHES COULD LINGER UNTIL 14Z-15Z. LG SCALE SUBSIDENCE AND DRY AIR ASSOCIATED WITH HIGH PRESSURE SYSTEM WILL PROVIDE THE AREA WITH ABUNDANT SUNSHINE LATER TODAY. GEFS 8H TEMPS SHOW MODERATION OF THIS ONCE CHILLY AIR MASS WITH MEAN 8H TEMPS NR 9C BY AFTN...SUPPORTIVE OF HIGHS IN THE U60S AND L70S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... DYING COLD FRONT...CURRENTLY OVR MICHIGAN...WILL PUSH INTO WESTERN PA TONIGHT...ACCOMPANIED BY AN INCREASE IN CLOUDS...BUT LITTLE IF ANY PRECIP. WILL RAMP UP POPS TO ARND 15 PCT OVERNIGHT ACROSS THE W MTNS WITH ARRIVAL OF THIS WEAK FRONT. HOWEVER...NEARLY ALL THE LG SCALE FORCING REMAINS WEST OF PA ASSOC WITH DEEPENING UPPER TROUGH...SO THE CHANCE OF ANY -SHRA WILL BE MINIMAL. SOUTHERLY FLOW AHEAD OF THIS BOUNDARY WILL DRAW HIGHER HUMIDITY BACK INTO THE REGION...RESULTING IN A MUCH MILDER NIGHT...WITH MINS MOSTLY ARND 50F. DYING COLD FRONT WILL WASH OUT OVR CENTRAL PA ON FRIDAY...PROVIDING THE FOCUS FOR SCT AFTN -SHRA. WILL PLACE AXIS OF HIGHEST POPS /ARND 30 PCT/ ACROSS THE CENTRAL COUNTIES...WHERE MDL DATA SHOWS TONGUE OF HIGHER SFC-8H THTE. DESPITE A PT-MOCLDY SKY...TEMPS SHOULD REACH NR SEASONAL NORMS FRI AFTN DUE TO WARMER RETURN SOUTHERLY FLOW AS SFC RIDGE PASSES OFF THE COAST. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... LITTLE SPREAD AMONG MED RANGE GUIDANCE WITH RESPECT TO THE LG SCALE PATTERN OVR THE NORTHEAST CONUS THIS WEEKEND. ALL GUIDANCE INDICATING UPPER LOW OVR ONTARIO GRADUALLY SHIFTS EAST...PUSHING A COLD FRONT THRU CENTRAL PA LATER SAT OR SAT NIGHT. AS MDL DATA HAS COME INTO LINE W/REGARDS TO TIMING OF FRONT...HAVE BUMPED POPS UP TO LIKELY FOR SAT PM. MDL DATA HINTING THAT ENOUGH HEATING/DESTABILIZATION WILL OCCUR AHEAD OF FROPA FOR MENTION OF THUNDER IN ADDITION TO THE SHOWERS. SOME UNCERTAINTY W/REGARDS TO AMT OF PRE-FRONTAL CLOUD COVER AND RESULTING CAPES. HOWEVER...STRONG DEEP LYR SHEAR...COMBINED WITH EVEN MARGINAL INSTABILITY...COULD POSE THE THREAT OF SVR WX OVR ROUGHLY THE EASTERN HALF OF THE STATE SAT AFTN. AS THE UPPER TROF AXIS CROSSES THE REGION ON SUNDAY...ADDITIONAL SHOWERS ARE POSSIBLE ACROSS MAINLY WESTERN AND NORTHERN SECTIONS. A RATHER TIGHT PRES GRADIENT WILL PRODUCE GUSTY W WIND ACROSS THE REGION...ACCENTUATING THE POST-FRONT CHILL. GEFS MEAN 8H TEMPS SUPPORT HIGHS FROM THE M50S NW MTNS TO THE U60S SE. FAIR BUT STILL COOL WEATHER APPEAR LIKELY EARLY NEXT WEEK AS UPPER TROUGH BEGINS TO LIFT OUT AND SFC HIGH PRES BUILDS EAST ACROSS THE OHIO VALLEY. GEFS AND ECMWF MEAN 8H TEMPS REMAIN BLW SEASONAL NORMS BOTH MON AND TUE. SFC HIGH PRES SYS WILL PASS OFF THE MID ATLANTIC COAST BY MID WEEK...ALLOWING A MILDER SW FLOW TO DEVELOP. && .AVIATION /09Z THURSDAY THROUGH MONDAY/... HIGH PRESSURE WILL REMAIN SITUATED OVER THE REGION LATE THIS WEEK. EXPECT VFR CONDITIONS OVERNIGHT FOR THE MAJORITY OF LOCATIONS... WITH SOME VALLEY FOG IMPACTING KIPT-KSEG WITH MVFR/IFR CONDITIONS THROUGH SUNRISE. DID NOT MENTION FOR KBFD AS WIND GRADIENT PICKS UP A LITTLE HEADING TOWARD SUNRISE. DURING THE DAY THU...VFR CONDITIONS WILL PREVAIL WITH ONLY SOME MID/HIGH CLOUDS STREAMING OVERHEAD. SURFACE WINDS DO PICK UP FROM THE SOUTH...INCREASING TO 10 MPH WITH GUSTS APPROACHING 20 MPH. OUTLOOK... FRI...MAINLY VFR. ISOLATED SHOWERS COULD PRODUCE LOCAL MVFR CONDITIONS. SAT...MAINLY VFR BUT A PERIOD OF MVFR CONDITIONS POSSIBLE IN LIKELY SHOWERS. SUN...MAINLY VFR BUT MVFR CONDITIONS POSSIBLE ACROSS THE HIGHER MTNS. MON...VFR...AS HIGH BUILDS ACROSS THE REGION. && .CTP WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR PAZ005-006-010- 011. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...FITZGERALD AVIATION...RXR ______________________________________________________________________ KCTP - Reference: ['late evening modis 11-3.7um satl imagery showing extensive valley'] 378 FXUS61 KCTP 010359 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 1159 PM EDT SUN SEP 30 2012 .SYNOPSIS... A DEEP UPPER LOW PRESSURE SYSTEM WILL QUICKLY LIFT NORTHEAST AND AWAY FROM PENNSYLVANIA TONIGHT. HIGH PRESSURE WILL BRIEFLY VISIT THE REGION ON MONDAY. WET WEATHER WILL RETURN TO THE KEYSTONE STATE MONDAY NIGHT THROUGH TUESDAY AS A WAVE OF LOW PRESSURE EJECTS NORTHWARD FROM THE CENTRAL GULF STATES. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... SHOWERS HAVE ENDED AND SKIES CLEARED LATE THIS EVENING...AS BLYR COOLS AND SFC RIDGE BUILDS INTO THE STATE FROM THE WEST. 11-3.9U SATL IMAGERY ALREADY SHOWING PATCHY FOG DEVELOPING ACROSS THE S TIER...WHERE GROUND IS WET FROM TODAY/S RAINFALL. BASED ON 02Z DWPT DEPRESSIONS AND LATEST MDL RH FCST...WILL EXPAND THE PATCHY FOG TO THE REST OF CENTRAL PA LATE TONIGHT. HAVE LOWERED MIN TEMPS ACROSS THE LAUREL HIGHLANDS AND SC MTNS...WHERE 18Z GEFS INDICATES THE WEAKEST GRADIENT AND DRIEST AIR /PWATS 1SD BLW NORMAL/. EXPECTED LOWS IN THE M30S IN THE COLDER VALLEYS OF THE ALLEGHENIES WILL LIKELY RESULT IN SOME PATCHY FROST BY DAWN...MAINLY ACROSS CAMBRIA/SOMERSET CO. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... AFTER SOME PATCHY EARLY MORNING FOG/LOW CLOUDS...SFC RIDGE WILL BISECT THE STATE...IN BETWEEN DEPARTING NRN STREAM UPPER TROUGH/LOW LIFTING NWD ACRS NRN NEW ENGLAND AND DEVELOPING SRN STREAM WAVE OVR MS/AL. EXPECT AN INCREASE IN MID-HIGH CLOUDS IN ADVANCE OF THE SRN SYSTEM LATE IN THE DAY...AS IT MOVES NWD INTO THE TN VLY BY 00Z TUE. HIGHS WILL BE QUITE PLEASANT IN THE 60S TO LOWER 70S NORTH TO SOUTH. MDLS IN DECENT AGREEMENT IN MOVG THE SFC WAVE INTO TN/KY BY THE END OF THE PERIOD. ANOMALOUS SLY LLJ WILL SUPPORT ROBUST NWD MSTR FLUX INTO THE AREA MON NGT...WITH PWATS SURGING TO +2-3SD BY 12Z TUE. ANOTHER INTERESTING FEATURE IS PERHAPS A DUEL MSTR FEED FM THE GOMEX AND ATM RIVER EMANATING FM THE BAHAMAS. THE LATTER SHOULD BECOME THE MAIN SOURCE OF HI PWATS INTO TUES. THE 12Z MODELS STILL DISPLAY SOME DETAIL DIFFS WITH THIS SYS AND THEREFORE ONLY MADE MINOR TWEAKS TO THE SHORT TERM FCST FOR THE DY2 FINALS. HOWEVER WITH SUPPORT FROM THE 12Z GEFS/09Z SREF...STILL FEEL THAT HIGHER POPS ARE JUSTIFIED /ESPECIALLY FROM 06-12Z TUES/ GIVEN THE STG WAA/ISENT LIFT AND MSTR TRANSPORT INTO THE REGION. && .LONG TERM /TUESDAY THROUGH SUNDAY/... BY TUES...LARGE SCALE PATTERN WILL FEATURE HIGH AMPLITUDE TROUGH WITH UPPER LOW CENTERED NEAR MISSOURI. SFC LOW WILL BE LIFTING INTO THE OHIO VALLEY DRAGGING AN OCCLUDED FRONT THROUGH PA LATER TUE OR TUE NIGHT. THE SHORT RANGE GUIDANCE SHOWS ERODING STABILITY AND SUGGESTS THE POSSIBILITY OF SOME CONVECTION AS THE FRONT GETS CLOSER TUES...MAINLY ACROSS THE SOUTHERN HALF. QPF ON TUE LOOKS TO BE AROUND 0.25 ON AVERAGE...BUT HIGHER AMOUNTS ARE POSS. SOAKING RAIN CONTINUES INTO TUE NIGHT/EARLY WED AS SOUTHERLY FLOW ALOFT RIDES OVER THE SFC LOW...AND SHORTWAVE ENERGY SLIDES AROUND BASE OF TROUGH BEFORE EJECTING INTO OHIO VALLEY WED. MODELS STILL HINTING AT WEAK SECONDARY SFC WAVE DEVELOPMENT TO OUR SE...WHICH MAY PEEL POTENTIAL FOR 1 INCH QPFS AWAY FROM PA RESULTING IN A WIDESPREAD LIGHT TO MODERATE RAIN...AND A MINIMAL FLOOD THREAT AT THIS TIME. AFTER THE SFC LOW/FRONT CLEARS THE AREA...THE UPPER LOW WILL THEN PUSH THROUGH WED/WED NIGHT...KEEPING MENTION OF SHOWERS IN THE FORECAST - MAINLY IN THE WEST AS DRY SLOT APPEARS TO WORK IN WITH RIDGE NOSING IN FROM THE SOUTH. THU AND FRI WILL SEE SFC RIDGING AND W/SW UPPER FLOW...WHICH SHOULD KEEP THE REGION DRY WITH NEAR/SLIGHTLY ABOVE NORMAL TEMPS. MODELS CONTINUE TO PRODUCE DIVERGING FORECASTS FOR THE WEEKEND. THE GEFS/GFS AND CANADIAN MODELS SHOW AN APPROACHING ALBEIT FADING FRONT LATER FRIDAY WITH THE PARENT UPPER SHORTWAVE WANTING TO SHEAR OUT WELL NORTH AND WEST OF HERE. THE ECMWF /UNUSUALLY/ CONTINUES TO BE AN OUTLIER...HOLDING ITS UPPER ENERGY BACK RESULTING IN A BROAD WSW FLOW EVENTUALLY ESTABLISHING OVER THE GR LAKES AND NERN US. THIS RESULTS IN THE MODEL DEVELOPING A SLOW MOVING WAVY ANA-FRONT THAT APPROACHES THE AREA FOR THE WEEKEND. TOUGH TO EVEN LEAN FORECAST ONE WAY OR THE OTHER WITH SUCH DIFFERENCE IN GUIDANCE...SO HAD TO KEEP LOW POPS ACROSS SEVERAL PERIODS...THOUGH PAINTED HIGHEST POPS ON SAT. FOR TEMPS...GRADUALLY OOZED COOLER TEMPERATURES INTO THE REGION FROM SAT INTO MON. && .AVIATION /04Z MONDAY THROUGH FRIDAY/... LATE EVENING MODIS 11-3.7UM SATL IMAGERY SHOWING EXTENSIVE VALLEY FOG HAS ALREADY FORMED ACROSS MUCH OF CENTRAL PA. SFC HIGH PRES BUILDING INTO THE REGION WILL PROVIDE THE MCLEAR SKY AND LGT WIND NECESSARY FOR CONTINUED COOLING AND EXPANSION OF THE FOG OVERNIGHT. IPT ALREADY HAS A 400FT CIG AT 0330Z AND SEE NO REASON FOR IMPROVEMENT OVERNIGHT. TAKING INTO ACCOUNT CURRENT DWPT DEPRESSIONS AND CLIMATOLOGY...IT APPEARS MOST AIRFIELDS WILL EXPERIENCE A PERIOD OF IFR CONDS IN FOG BEFORE THE NIGHT IS THROUGH. UNFAVORABLE CLIMATOLOGY AT MDT WOULD SUGGEST THAT AIRFIELD MAY ESCAPE SIG VIS RESTRICTIONS. ANY EARLY FOG SHOULD BURN OFF BTWN 12Z-14Z. FOR THE REST OF THE DAY...A NEAR CERTAINTY OF VFR CONDS AND LGT WINDS...AS SFC HIGH REMAINS OVR THE REGION. LOW PRES LIFTING NORTH INTO THE OHIO VALLEY WILL BRING LOWERING CLOUDS AND CHC OF RAIN MON NIGHT. OUTLOOK... TUE...RAIN/LOW CIGS POSSIBLE. WED...AM RAIN/LOW CIGS/FOG POSSIBLE. THU-FRI...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...STEINBUGL NEAR TERM...DEVOIR/FITZGERALD SHORT TERM...STEINBUGL LONG TERM...RXR AVIATION...FITZGERALD ______________________________________________________________________ KCTP - Reference: ['early morning modis 11-3.7um satl imagery showing extensive '] 654 FXUS61 KCTP 010712 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 312 AM EDT MON OCT 1 2012 .SYNOPSIS... HIGH PRESSURE WILL BRIEFLY VISIT THE REGION TODAY. WET WEATHER WILL RETURN TO THE KEYSTONE STATE TONIGHT THROUGH WEDNESDAY AS A WAVE OF LOW PRESSURE EJECTS NORTHWARD FROM THE CENTRAL GULF STATES. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... FOG PRODUCT SHOWS LOW CLOUDS AND FOG FORMING RAPIDLY IN THE REGIONAL VALLEYS WHILE THIN HIGH CLOUDS MAKE SLOW INROADS OVER SWRN PA. IF THE HIGH CLOUDS HOLD OFF LONG ENOUGH...THE FIRST VISUALS OF THE DAY SHOULD REVEAL A PRETTY MUCH CLASSIC DENDRITIC FOG PATTERN IN CENTRAL PA. EXPECTED LOWS IN THE M30S IN THE COLDER VALLEYS OF THE ALLEGHENIES WILL LIKELY RESULT IN SOME PATCHY FROST BY DAWN. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... AFTER SOME PATCHY EARLY MORNING FOG/LOW CLOUDS...SFC RIDGE WILL BISECT THE STATE...IN BETWEEN DEPARTING NRN STREAM UPPER TROUGH/LOW LIFTING NWD ACRS NRN NEW ENGLAND AND DEVELOPING SRN STREAM WAVE OVR MS/AL. EXPECT AN INCREASE IN MID-HIGH CLOUDS IN ADVANCE OF THE SRN SYSTEM LATE IN THE DAY...AS IT MOVES NWD INTO THE TN VLY BY 00Z TUE. HIGHS WILL BE QUITE PLEASANT IN THE 60S TO LOWER 70S NORTH TO SOUTH. MDLS IN DECENT AGREEMENT IN MOVG THE SFC WAVE INTO TN/KY BY THE END OF THE PERIOD. ANOMALOUS SLY LLJ WILL SUPPORT ROBUST NWD MSTR FLUX INTO THE AREA MON NGT...WITH PWATS SURGING TO +2-3SD BY 12Z TUE. ANOTHER INTERESTING FEATURE IS PERHAPS A DUEL MSTR FEED FM THE GOMEX AND ATM RIVER EMANATING FM THE BAHAMAS. THE LATTER SHOULD BECOME THE MAIN SOURCE OF HI PWATS INTO TUES. THE 12Z MODELS STILL DISPLAY SOME DETAIL DIFFS WITH THIS SYS AND THEREFORE ONLY MADE MINOR TWEAKS TO THE SHORT TERM FCST FOR THE DY2 FINALS. HOWEVER WITH SUPPORT FROM THE 12Z GEFS/09Z SREF...STILL FEEL THAT HIGHER POPS ARE JUSTIFIED /ESPECIALLY FROM 06-12Z TUES/ GIVEN THE STG WAA/ISENT LIFT AND MSTR TRANSPORT INTO THE REGION. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... BY TUES...LARGE SCALE PATTERN WILL FEATURE HIGH AMPLITUDE TROUGH WITH UPPER LOW CENTERED NEAR MISSOURI. SFC LOW WILL BE LIFTING INTO THE OHIO VALLEY DRAGGING AN OCCLUDED FRONT THROUGH PA LATER TUE OR TUE NIGHT. THE SHORT RANGE GUIDANCE SHOWS ERODING STABILITY AND SUGGESTS THE POSSIBILITY OF SOME CONVECTION AS THE FRONT GETS CLOSER TUES...MAINLY ACROSS THE SOUTHERN HALF. QPF ON TUE LOOKS TO BE AROUND 0.25 ON AVERAGE...BUT HIGHER AMOUNTS ARE POSS. SOAKING RAIN CONTINUES INTO TUE NIGHT/EARLY WED AS SOUTHERLY FLOW ALOFT RIDES OVER THE SFC LOW...AND SHORTWAVE ENERGY SLIDES AROUND BASE OF TROUGH BEFORE EJECTING INTO OHIO VALLEY WED. MODELS STILL HINTING AT WEAK SECONDARY SFC WAVE DEVELOPMENT TO OUR SE...WHICH MAY PEEL POTENTIAL FOR 1 INCH QPFS AWAY FROM PA RESULTING IN A WIDESPREAD LIGHT TO MODERATE RAIN...AND A MINIMAL FLOOD THREAT AT THIS TIME. AFTER THE SFC LOW/FRONT CLEARS THE AREA...THE UPPER LOW WILL THEN PUSH THROUGH WED/WED NIGHT...KEEPING MENTION OF SHOWERS IN THE FORECAST - MAINLY IN THE WEST AS DRY SLOT APPEARS TO WORK IN WITH RIDGE NOSING IN FROM THE SOUTH. THU AND FRI WILL SEE SFC RIDGING AND W/SW UPPER FLOW...WHICH SHOULD KEEP THE REGION DRY WITH NEAR/SLIGHTLY ABOVE NORMAL TEMPS. MODELS CONTINUE TO PRODUCE DIVERGING FORECASTS FOR THE WEEKEND. THE GEFS/GFS AND CANADIAN MODELS SHOW AN APPROACHING ALBEIT FADING FRONT LATER FRIDAY WITH THE PARENT UPPER SHORTWAVE WANTING TO SHEAR OUT WELL NORTH AND WEST OF HERE. THE ECMWF /UNUSUALLY/ CONTINUES TO BE AN OUTLIER...HOLDING ITS UPPER ENERGY BACK RESULTING IN A BROAD WSW FLOW EVENTUALLY ESTABLISHING OVER THE GR LAKES AND NERN US. THIS RESULTS IN THE MODEL DEVELOPING A SLOW MOVING WAVY ANA-FRONT THAT APPROACHES THE AREA FOR THE WEEKEND. TOUGH TO EVEN LEAN FORECAST ONE WAY OR THE OTHER WITH SUCH DIFFERENCE IN GUIDANCE...SO HAD TO KEEP LOW POPS ACROSS SEVERAL PERIODS...THOUGH PAINTED HIGHEST POPS ON SAT. FOR TEMPS...GRADUALLY OOZED COOLER TEMPERATURES INTO THE REGION FROM SAT INTO MON. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... EARLY MORNING MODIS 11-3.7UM SATL IMAGERY SHOWING EXTENSIVE VALLEY FOG AND LOWER CLDS AT THE CURRENT TIME. SOME SPOTS WILL BE IFR OR LIFR...WHILE OTHERS WILL REMAIN MAINLY MVFR AND VFR. EXPECT CONDITIONS TO IMPROVE BY MID MORNING...BUT HI CLDS WILL MOVE NORTHWARD DURING THE DAY...BUT CONDITIONS SHOULD BE VFR. CLDS AND SHOWERS WILL QUICKLY WORK TO THE NE LATE TODAY... AS VERY STRONG WARM ADVECTION SETS UP. MUCH OF TUE INTO WED WILL FEATURE SHOWERS AND THUNDERSTORMS. WHILE THE BEST DYNAMICS WILL BE WEST OF THE MTS...STILL THINK A FEW STRONG STORMS WITH HEAVY RAIN WILL BE LIKELY... GIVEN HIGH PW VALUES. IMPROVING CONDITIONS FOR LATER WED INTO THU...AS HIGH PRESSURE BUILDS NE FROM WESTERN NC. ANOTHER COLD FRONT FOR LATE FRIDAY INTO THE WEEKEND...BUT TIMING NOT CLEAR CUT...AS SEVERAL DAYS OUT...AND MODELS SHOW A LOT OF VARIATION. SUSPECT FRONT WILL COME IN SLOWER THAN EXPECTED...AS A RATHER STRONG RIDGE IS FCST TO BE JUST OFF THE SE COAST. OUTLOOK... TUE...RAIN/LOW CIGS. WED...AM RAIN/LOW CIGS. THU-FRI...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...DEVOIR/FITZGERALD/LA CORTE SHORT TERM...STEINBUGL LONG TERM...RXR AVIATION...MARTIN ______________________________________________________________________ KCTP - Reference: ['early morning modis 11-3.7um imagery showing some valley fog this'] 595 FXUS61 KCTP 051026 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 626 AM EDT FRI OCT 5 2012 .SYNOPSIS... A DYING COLD FRONT WILL STALL OUT AS IT ENTERS NORTHWEST PA TODAY. A WAVE OF LOW PRESSURE RIDING ALONG THIS BOUNDARY WILL LIFT THROUGH NORTHWEST PENNSYLVANIA TONIGHT...DRAGGING THE TRAILING COLD FRONT THROUGH THE REST OF THE STATE SATURDAY MORNING. AN UPPER LVL SHORTWAVE WILL MOVE ACROSS THE AREA ON SUNDAY...FOLLOWED BY SFC HIGH PRESSURE EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... EARLY MORNING MODIS 11-3.7UM IMAGERY SHOWING SOME VALLEY FOG THIS MORNING...MOST PREVALENT ALONG THE I-80 CORRIDOR. LAMP GUIDANCE AND NAM SFC RH FIELDS SUGGEST THIS FOG WILL BURN OFF BTWN 13Z-15Z. A SHORTWAVE LIFTING NORTHWARD ACROSS LK SUPERIOR IS PUSHING A DYING COLD FRONT TOWARD PA EARLY THIS MORNING. LATEST MDL DATA INDICATES THIS FRONT WILL STALL OUT ACROSS NORTHWEST PA LATER TODAY...PERHAPS PROVIDING THE FOCUS FOR A FEW AFTN SHRA/TSRA ACROSS THE N MTNS. SKIES WILL STAY MOSTLY SUNNY FOR THE BULK OF THE DAY ACROSS THE LOWER SUSQUEHANNA VALLEY...WHILE MOST OF NORTHERN PA WILL SEE MORNING SUNSHINE FOLLOWED BY INCREASING AFTERNOON CLOUDS ASSOC WITH APPROACH OF DYING FRONT. ENS MEAN 850 TEMPS SUPPORT HIGHS FROM THE M60S ACROSS THE NW MTNS...WHERE SUNSHINE WILL BE LIMITED...TO ARND 80F ACROSS THE LOWER SUSQ VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... FAST-MOVING SHORTWAVE ROUNDING BASED OF UPPER TROF WILL CAUSE WEAK CYCLOGENESIS ALONG STALLED FRONT OVR THE OHIO VALLEY THIS EVENING. THIS WAVE IS PROGGED BY ALL MDLS TO TRACK ACROSS NORTHWEST PA TONIGHT...BRINGING OUR NW COUNTIES A PERIOD OF STEADY RAIN AFTER MIDNIGHT. STRONGEST FORCING AND RIBBON OF MDL 8-7H FRONTOGENESIS APPEARS ACROSS THE NW MTNS LATE TONIGHT AND EARLY SAT AM. DURING THIS TIME...BLEND OF OPER AND ENS MEAN QPF SUGGESTS UP TO 0.75 INCHES COULD FALL ACROSS WARREN CO...WITH RAPIDLY DIMINISHING AMTS FURTHER SE. MOST OF CENTRAL PA WILL REMAIN IN THE RELATIVELY QUIET /DRY/ WARM SECTOR SOUTH OF LOW TRACK TONIGHT. HOWEVER...TRAILING COLD FRONT WILL SWEEP ACROSS THE AREA SAT AM...ACCOMPANIED BY SCT SHRA. THICKENING CLOUD COVER AND MAINLY RAIN FREE CONDITIONS AHEAD OF THE FRONT WILL KEEP TEMPS TONIGHT ON THE MILD SIDE...AND IN THE 50-55F RANGE FOR LOWS SE OF THE MTNS...WHILE THE NW MTNS AND LAURELS COOL OFF TO THE LOWER AND MID 40S BEHIND FRONT. MDLS INDICATE AN ANAFRONT STRUCTURE WITH BULK OF CLOUDS/SHRA BEHIND COLD FRONT...ASSOC WITH THERMALLY DIRECT CIRCULATION OF JET ENTRANCE REGION. WESTERLY FLOW WITHIN THIS POST-FRONTAL REGIME SHOULD TEND TO DRY UP SHOWERS EAST OF THE MTNS. WILL PLACE LIKELY POPS ACROSS THE ALLEGHENY MTNS THRU LATE MORNING...BUT ONLY ARND 25 PCT CHC ACROSS THE LOWER SUSQ VALLEY. BY AFTN...EXPECT ANY SHOWERS TO BE PASSING EAST OF THE REGION AND SKIES SHOULD PARTIALLY CLEAR...AS LOW PWAT AIR FLOWS INTO THE STATE ON WESTERLY FLOW. TEMPS SATURDAY WILL LIKELY RANGE FROM THE L50S OVR THE NW MTNS...TO ARND 70F OVR THE LOWER SUSQ VALLEY. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... TIMING DIFFS HAVE BECOME MINIMAL WITH PASSAGE OF SHORTWAVE ROUNDING BASE OF UPPER TROF ACROSS THE OHIO VALLEY ON SUNDAY. UPPER LVL WAA AHEAD OF THIS SYSTEM MAY SPREAD INCREASING HIGH CLOUDS OVER THE AREA AS EARLY AS SAT NIGHT. HOWEVER...BEST CHC OF SHOWERS WILL OCCUR IN CONJUNCTION WITH PASSAGE OF SHORTWAVE AND DIURNAL HEATING SUN AFTN. MOISTURE WILL BE LACKING WITH THIS SYSTEM. HOWEVER...STRONG LG SCALE FORCING...AS IMPLIED BY MDL 500-300MB Q-VECTOR DIVERGENCE...SHOULD BE SUFFICIENT TO PRODUCE MEASURABLE RAIN IN MOST SPOTS ON SUNDAY. TEMPS ACTUALLY BECOME COLD ENOUGH TO SUPPORT A FEW SNOWFLAKES MIXED WITH THE SHRA SUNDAY EVENING OVR THE HIGH TERRAIN OF ALLEGHENIES...AS UPPER SHORTWAVE SWINGS THRU. IN THE LONGER RANGE...GOOD AGREEMENT AMONG OPER MDLS AND ENSEMBLES THRU NEXT WEEK...ALL OF WHICH PLACE MEAN UPPER TROF AXIS OVR THE GRT LKS. NOTABLE SHORTWAVES ROTATING ARND THIS FEATURE SHOULD AFFECT PA WED AND THU NITE/FRIDAY. SFC ANTICYCLONE/LOW PWAT AIR PASSING OVR THE STATE SHOULD ENSURE FAIR AND COOL WEATHER EARLY IN THE WEEK. AS MENTIONED ABOVE...PASSAGE OF SHORTWAVE AND ASSOC COLD FRONT ON WED...WILL BRING A CHC OF SHOWERS. AFTER THAT...NEXT OPPORTUNITY FOR SHOWERS WILL BE WITH ARRIVAL OF ANOTHER SHORTWAVE THU NITE OR FRIDAY. WITH THE POSSIBLE EXCEPTION OF TUESDAY...TEMPS SHOULD AVERAGE BLW NORMAL THRU NEXT WEEK...AS WE REMAIN UNDER INFLUENCE OF LARGE UPPER TROF AND BLW NORMAL 850 TEMPS. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... HIGH PRESSURE ACROSS THE AREA OVERNIGHT INTO FRIDAY WILL KEEP CONDITIONS PRIMARILY VFR. THE EXCEPTIONS WILL BE MAINLY AT THE EASTERN THREE TAF SITES /KIPT-KLNS-KMDT/. ALL HAVE DEWPOINT DEPRESSIONS AT 2 DEGREES OR LESS...SO EXPECT MVFR VSBY WITH IFR CIGS AT KIPT AFTER 06Z...AND MVFR VSBYS DEVELOPING AT KLNS-KMDT WITH BRIEF IFR POSS TOWARD SUNRISE. SHORT-LIVED MVFR VSBY MAY DEVELOP AT KBFD AFTER 08Z AS WELL. FRI AFTERNOON...A WEAKENING COLD FRONT WORKS INTO NW PA...BRINGING INCREASING CLOUDS AND CHANCE OF SHOWERS BEFORE 00Z SAT TO KBFD...THOUGH CONDITIONS WILL REMAIN VFR. ELSEWHERE MOSTLY SUNNY SKIES ON TAP FOR THE BULK OF THE DAY WITH INCREASING CLOUDS LATE. MVFR CIGS AND VSBYS IN PERIODS OF RAIN WILL COVER THE NW THIRD OF THE STATE FRIDAY NIGHT AND EARLY SAT /MAINLY IMPACTING KBFD/...WITH MAINLY VFR CONTINUING ACROSS REMAINDER OF THE CWA. CONDITIONS MAY DROP TO MVFR ALONG THE KJST-KUNV-KIPT LINE DURING THE MID-LATE MORNING SAT AS THE FRONT PUSHES THROUGH. OUTLOOK... SAT...AM LOW CIGS/FOG POSSIBLE...MAINLY AT BFD AND JST. VFR TO PERIODS OF MVFR ACROSS THE SE HALF OF THE STATE. SUN AND SUN NIGHT...RAIN/LOW CIGS POSSIBLE. PRECIPITATION MAY TURN TO A MIX OF RAIN...SLEET AND WET SNOW BY SUNDAY NIGHT INVOF OF KBFD. MON AND TUE...PERIODS OF MVFR CIGS AND VSBYS POSSIBLE MONDAY IN SCATTERED SHRA ACROSS THE HIGH TERRAIN OF WESTERN PENN. OTHERWISE...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...FITZGERALD AVIATION...RXR ______________________________________________________________________ KCTP - Reference: ['tonight...expect patchy valley fog to form. modis 11-3.7um imagery'] 338 FXUS61 KCTP 090620 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 220 AM EDT TUE OCT 9 2012 .SYNOPSIS... A LARGE UPPER LEVEL TROUGH WILL REMAIN POSITIONED OVER THE GREAT LAKES THROUGH THE END OF THIS WEEK. SHORTWAVES ROTATING AROUND THE BASE OF THIS TROUGH WILL PUSH REINFORCING COLD FRONTS THROUGH PENNSYLVANIA ON WEDNESDAY AND FRIDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... EARLY AM RADAR LOOP CONTINUES TO SHOW BAND OF -SHRA TRAINING OVR LANCASTER CO...COINCIDENT WITH AXIS OF MDL 8-7H FGEN FORCING...WHICH IS PROGGED TO WEAKEN AND LIFT NE INTO NEW ENGLAND WITH PASSAGE OF UPPER LVL SHORTWAVE BY ARND 12Z. WILL GRADUALLY LOWER POPS ACROSS THE SE ZONES BTWN 06Z-12Z. WAA AHEAD OF SHORTWAVE IS PRODUCING OVERCAST SKIES ACROSS NEARLY ALL OF CENTRAL PA EARLY THIS MORNING...HOLDING TEMPS UP. WHERE SKIES ARE CLEAR...TEMPS HAVE ALREADY DROPPED TO ARND FREEZING ACROSS WARREN/MCKEAN COUNTIES AT 05Z. PASSAGE OF SHORTWAVE ARND DAWN SHOULD BRING CLEARING SKIES TO THE ALLEGHENIES. HOWEVER...IT/S A CLOSE CALL AS TO HOW COLD TEMPS GET. CURRENTLY BELIEVE PATCHY FROST WITH MINS IN THE M30S SHOULD DO IT ACROSS THE LAURELS. FURTHER EAST...LITTLE RISK OF FROST...AS SKIES SHOULD REMAIN MAINLY CLOUDY. WHERE SKIES PARTIALLY CLEAR ACROSS THE W MTNS LATE TONIGHT...EXPECT PATCHY VALLEY FOG TO FORM. MODIS 11-3.7UM IMAGERY SHOWS VALLEY FOG HAS ALREADY FORMED ACROSS WARREN CO AT 04Z. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/... ANY -SHRA ACROSS LANCASTER CO SHOULD BE ENDING BY ARND 12Z...AS SHORTWAVE PASSES EAST OF THE STATE. CLEARING SKIES WILL SLOWLY OVERSPREAD THE REGION LATER TODAY AS DRIER AIR WORKS IN FROM THE WEST. HOWEVER...MOISTURE TRAPPED BENEATH SUBSIDENCE INVERSION WILL LIKELY KEEP SKIES MAINLY CLOUDY ACROSS EASTERN PA. DON/T EXPECT A SIGNIFICANT SPREAD IN HIGH TEMPS...AS SUNSHINE HELPS WARM THE NORMALLY COOLER W MTNS. MAX TEMPS SHOULD RANGE FROM THE U50S TO L60S OVER MOST OF THE AREA. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... EXCELLENT MDL AGREEMENT WITH REGARDS TO TIMING OF NEXT SHORTWAVE ROUNDING BASE OF GRT LKS TROF ON WEDNESDAY. THIS MOISTURE-STARVED SYSTEM AND ASSOC COLD FRONT SHOULD SWEEP THROUGH CENTRAL PA DURING THE DAYLIGHT HRS...ACCOMPANIED BY A FEW SHOWERS...PRIMARILY OVR THE N MTNS. WED NIGHT WILL BE ON THE COOL SIDE AGAIN...MAY BE JUST ENOUGH WIND TO KEEP MOST AREAS ABOVE FREEZING. HIGH CONFIDENCE OF SUNNY/DRY WX THURSDAY...WHEN ALL MDL DATA TRACKS SFC RIDGE ACROSS OUR AREA. THU NIGHT MAY FEATURE FROST...FREEZE ISSUES...ESPECIALLY AWAY FROM NW PA...IF THE GRADIENT AND CLD COVER IS SLOW TO INCREASE. ANOTHER MOISTURE- STARVED COLD FRONT FOR FRIDAY...WITH FAIRLY LOW POPS. FRI NITE COULD BE ANOTHER COLD ONE AS HIGH PRES WITH LOW PW AT AIR DRIFTS OVR THE STATE. MODELS HINT AT A PATTERN CHANGE BY LATE IN THE WEEKEND. WARMER WX APPEARS LIKELY BY SUNDAY AS HIGH PRESSURE MOVES OFF THE COAST AND RETURN SW FLOW DEVELOPS. SOME SHOWERS POSSIBLE WITH WARM FRONT SATURDAY NIGHT...AND SUNDAY WITH THE COLD FRONT. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... SCATTERED SHOWERS CONTINUE TO FADE AND DISSIPATE AS THE EVENING CONTINUES. A BRIEF LINE HAS FORMED ALONG A BOUNDARY TO THE NORTHEAST AND SOUTH WEST OVER RENOVO. THIS WILL MOVE TO THE NORTHEAST AND ANY ACCUMULATIONS WILL BE LIGHT. THIS IS INDICATIVE OF THE AMOUNT OF MOISTURE IN THE LOW LEVELS...WHICH SHOULD ALLOW FOR THE FORMATION AND CONTINUATION OF LOW STRATOCU OVERNIGHT. EXPECT GRADUALLY LOWERING CEILINGS LIKELY FROM SEG SOUTH AND EAST. HAVE BROUGHT ALL TERMINALS DOWN TO MVFR/IFR BY LATE EVENING. BFD...WITH MOIST SOUTHERLY FLOW THAT CONTINUES TO ADVECT NORTHWARD. BFD SHOULD SEE REDUCING CIGS AND VSBYS BY 06Z THROUGH 15Z. CONDITIONS WILL BEGIN TO IMPROVE FROM WEST TO EAST TUESDAY MORNING THROUGH ABOUT MID DAY AS THE WEAK STORM SYSTEM MOVES OFF TOWARD NEW ENGLAND AND WEAK HIGH PRESSURE MOVES INTO THE REGION. OUTLOOK... WED...VFR...BUT MVFR POSS IN SCATTERED SHOWERS WITH A COLD FRONTAL PASSAGE...ESPECIALLY WESTERN HIGH TERRAIN. THU...VFR. FRI...VFR...BUT MVFR POSS IN SCATTERED SHOWERS WITH A COLD FRONTAL PASSAGE...ESPECIALLY WESTERN HIGH TERRAIN. SAT...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR PAZ004>006-037. && $$ SYNOPSIS...DANGELO/LA CORTE NEAR TERM...FITZGERALD SHORT TERM...DANGELO/FITZGERALD LONG TERM...MARTIN AVIATION...LA CORTE/CERU ______________________________________________________________________ --- Site: KCYS --- --- Site: KDDC --- --- Site: KDLH --- --- Site: KDMX --- --- Site: KDTX --- --- Site: KDVN --- --- Site: KEAX --- --- Site: KEKA --- KEKA - Reference: ['.aviation...05z modis 11-4u imagery showed fg across interior'] 759 FXUS66 KEKA 021128 AFDEKA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE EUREKA CA 328 AM PST FRI MAR 2 2012 .SYNOPSIS...A RIDGE OF HIGH PRESSURE BUILDING OVER THE WEST COAST WILL BRING NORTHWEST CALIFORNIA DRY CONDITIONS THROUGH THE WEEKEND. THE NEXT THREAT OF RAIN COMES IN THE FORM OF A STORM SYSTEM EARLY NEXT WEEK. && .DISCUSSION...COLD AIR OVER THE REGION COMBINED WITH MOSTLY CLEAR SKIES HAS ALLOWED TEMPERATURES TO FALL TO AROUND FREEZING EARLY THIS MORNING ALONG THE COAST. SINCE GROWING SEASON HAS JUST STARTED FOR THE COAST, ISSUED A FREEZE WARNING FOR THE REDWOOD COAST. ISSUED A FROST ADVISORY FOR THE MENDOCINO COAST BECAUSE TEMPERATURES THERE ARE SLIGHTLY WARMER. TEMPERATURES WILL QUICKLY WARM UP BY LATE MORNING, SETTING THE STAGE FOR A NICE DAY. A RIDGE OF HIGH PRESSURE BUILDING OVER THE WEST COAST WILL BRING NORTHWEST CALIFORNIA DRY CONDITIONS THROUGH THE WEEKEND. A WEAK FRONT PASSING TO OUR NORTH TODAY MAY BRING SOME CLOUDS TO DEL NORTE COUNTY, BUT OTHER THAN THAT IT SHOULD BE MOSTLY SUNNY ACROSS MOST OF THE AREA. TEMPERATURES TONIGHT WILL BE A FEW DEGREES WARMER IN THE MODERATING AIR MASS, THOUGH PATCHY FOG MAY OCCUR AGAIN. THE WEEKEND LOOKS GREAT, MOSTLY SUNNY WITH SOME INLAND TEMPERATURES HITTING THE 70 DEGREE MARK. EVEN PORTIONS OF THE COAST MIGHT HIT 60 DEGREES THIS WEEKEND. ENJOY THE GOOD WEATHER WHILE IT LASTS. THE NEXT THREAT OF RAIN COMES IN THE FORM OF A STORM SYSTEM EARLY NEXT WEEK. MODELS ARE IN GOOD AGREEMENT SHOWING RAIN LATE MONDAY INTO TUESDAY. BUMPED UP POPS TO REFLECT THIS. IT'S STILL TOO EARLY TO DETERMINE QPF AMOUNTS, BUT SNOW LEVELS LOOK LIKE THEY WILL BE MOSTLY ABOVE PASS LEVELS. BEYOND THAT THE MODELS DIVERGE IN SOLUTIONS, SO STAYED WITH MOSTLY CLIMO POPS IN THE LONG TERM. && .AVIATION...05Z MODIS 11-4U IMAGERY SHOWED FG ACROSS INTERIOR VALLEYS WITH OBS AT FOT AND O54 REPORTING VLIFR ATTM. EXPECT FG TO DISSIPATE BY 17Z WITH VFR CONDITIONS PREVAILING INTO THIS EVENING. EXPECT FG TO DEVELOP AGAIN OVERNIGHT RESULTING IN IFR CONDITIONS. HOWEVER...WEAK OFFSHORE GRADIENT MAY INHIBIT FG DEVELOPMENT TO THE COAST. && .MARINE...NLY WINDS WILL CONTINUE TO GRADUALLY DIMINISH OVER THE WATERS TODAY. HOWEVER...ADVISORY LEVEL WINDS WILL PERSIST INTO THIS EVENING OFFSHORE S OF CAPE MENDO. LGT TO MDT NLY WINDS WILL PERSIST THROUGH THE WEEKEND AS HIGH PRESSURE PREVAILS. WINDS AND SEAS WILL INCREASE EARLY NEXT WEEK AS ANOTHER STORM SYSTEM IMPACTS THE WATERS. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... FREEZE WARNING FOR CAZ001. FROST ADVISORY FOR CAZ002. NORTHWEST CALIFORNIA COASTAL WATERS... SMALL CRAFT ADVISORY FOR PZZ450-455-470-475. && $$ VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA FOLLOW US ON FACEBOOK AT: HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV ______________________________________________________________________ KEKA - Reference: ['.aviation...06z modis pass showed some fg in the van duzen river'] 902 FXUS66 KEKA 241033 AFDEKA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE EUREKA CA 333 AM PDT FRI AUG 24 2012 .SYNOPSIS...HIGH PRESSURE OVER THE REGION WILL MAINTAIN SEASONAL TEMPERATURES AND MAINLY CLEAR SKIES WITH THE EXCEPTION OF NIGHT AND MORNING COASTAL CLOUDS. COOLER TEMPERATURES AND INCREASED CLOUD COVER EXPECTED EARLY NEXT WEEK AS A SYSTEM PASSES TO THE NORTH. && .DISCUSSION...WV IMAGERY SHOWS UPPER LOW MOVING THROUGH THE PAC NW ATTM WITH UPPER RIDGE PREVAILING OVER THE REGION. THIS WILL MAINTAIN SEASONAL TEMPS AND MOSTLY SUNNY SKIES ACROSS THE REGION TODAY. UPPER RIDGE WILL BEGIN TO SHIFT E SAT AS A LONG WAVE TROUGH DEEPENS OVER THE NE PAC. MODELS IN DECENT AGREEMENT IN THIS TROUGH IMPACTING THE NW U.S. THROUGH WED BEFORE SHIFTING INLAND. HOWEVER... MODELS SHOW ONLY FAIR AGREEMENT IN STRENGTH AND TIMING OF THIS FEATURE. CONTINUED THE TREND OF A GENERAL MODEL BLEND TO ACCOUNT FOR DIFFERENCES. ALTHOUGH DETAILS ARE HARD TO PIN DOWN ATTM...A COOLER WX PATTERN WITH GREATER COASTAL FG/STRATUS COVERAGE IS IN STORE FOR THE FIRST HALF OF NEXT WEEK. && .MARINE...HAVE MADE FEW CHANGES TO THE EXISTING FORECAST PACKAGE. EARLIER WINDSAT PASS VERIFIES WELL AGAINST GRIDS. WINDS ARE FORECAST TO DROP OFF RAPIDLY TONIGHT AND SAT. DID EXTEND THE N OFFSHORE GALE WARNING 3 HOURS WHICH BLENDS BETTER WITH MFR AND FORECAST WIND GUSTS. WIND GUSTS OVER 40 KT ARE POSSIBLE THRU TODAY OVER THE EXTREME N PORTION OF THE OFFSHORE WATERS. LIGHT WINDS WITH SEAS LESS THAN 5 FT ARE EXPECTED LATE IN THE WEEKEND AND INTO EARLY NEXT WEEK. /SEC && .AVIATION...06Z MODIS PASS SHOWED SOME FG IN THE VAN DUZEN RIVER VALLEY WITH MOSTLY CLEAR SKIES ACROSS REST OF CWA. EXPECT PERSISTENCE TO RULE THE DAY AS UPPER RIDGE PREVAILS ACROSS THE REGION. SOME PATCHY FG/STRATUS MAY DEVELOP ALONG THE COAST AROUND SUNRISE BUT WILL BE SHORT LIVED. VFR CONDITIONS WILL PREVAIL ACROSS THE REGION TODAY WITH SOME MVFR VSBY AROUND ROUND VALLEY DUE TO SMOKE FROM THE N PASS FIRE. && .EKA WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY UNTIL 5 AM PDT SATURDAY PZZ450-455. GALE WARNING UNTIL 11 PM PDT THIS EVENING PZZ470. GALE WARNING UNTIL 3 PM PDT THIS AFTERNOON PZZ475. && $$ VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA FOLLOW US ON FACEBOOK AND TWITTER AT: HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV HTTP://WWW.TWITTER.COM/NWSEUREKA ______________________________________________________________________ KEKA - Reference: ['aviation...06z modis pass showed some fg in the van duzen river'] 332 FXUS66 KEKA 241648 AFDEKA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE EUREKA CA 948 AM PDT FRI AUG 24 2012 .SYNOPSIS...HIGH PRESSURE OVER THE REGION WILL MAINTAIN SEASONAL TEMPERATURES AND MAINLY CLEAR SKIES WITH THE EXCEPTION OF NIGHT AND MORNING COASTAL CLOUDS. COOLER TEMPERATURES AND INCREASED CLOUD COVER EXPECTED EARLY NEXT WEEK AS A SYSTEM PASSES TO THE NORTH. .UPDATE...DID A QUICK UPDATE TO THE FORECAST THIS MORNING TO ADD AREAS OF SMOKE TO MUCH OF INTERIOR HUMBOLDT...DEL NORTE AND TRINITY COUNTIES. EXPECT THE AFTERNOON WESTERLIES WILL PUSH THE SMOKE BACK TO THE EAST. TONIGHT EXPECT SMOKE WILL RETURN IN A FAIRLY SIMILAR FASHION. ALSO MADE A FEW MINOR TWEAKS TO THE CLOUD COVER. MKK && .PREV DISCUSSION... /ISSUED 333 AM PDT FRI AUG 24 2012/ DISCUSSION...WV IMAGERY SHOWS UPPER LOW MOVING THROUGH THE PAC NW ATTM WITH UPPER RIDGE PREVAILING OVER THE REGION. THIS WILL MAINTAIN SEASONAL TEMPS AND MOSTLY SUNNY SKIES ACROSS THE REGION TODAY. UPPER RIDGE WILL BEGIN TO SHIFT E SAT AS A LONG WAVE TROUGH DEEPENS OVER THE NE PAC. MODELS IN DECENT AGREEMENT IN THIS TROUGH IMPACTING THE NW U.S. THROUGH WED BEFORE SHIFTING INLAND. HOWEVER... MODELS SHOW ONLY FAIR AGREEMENT IN STRENGTH AND TIMING OF THIS FEATURE. CONTINUED THE TREND OF A GENERAL MODEL BLEND TO ACCOUNT FOR DIFFERENCES. ALTHOUGH DETAILS ARE HARD TO PIN DOWN ATTM...A COOLER WX PATTERN WITH GREATER COASTAL FG/STRATUS COVERAGE IS IN STORE FOR THE FIRST HALF OF NEXT WEEK. MARINE...HAVE MADE FEW CHANGES TO THE EXISTING FORECAST PACKAGE. EARLIER WINDSAT PASS VERIFIES WELL AGAINST GRIDS. WINDS ARE FORECAST TO DROP OFF RAPIDLY TONIGHT AND SAT. DID EXTEND THE N OFFSHORE GALE WARNING 3 HOURS WHICH BLENDS BETTER WITH MFR AND FORECAST WIND GUSTS. WIND GUSTS OVER 40 KT ARE POSSIBLE THRU TODAY OVER THE EXTREME N PORTION OF THE OFFSHORE WATERS. LIGHT WINDS WITH SEAS LESS THAN 5 FT ARE EXPECTED LATE IN THE WEEKEND AND INTO EARLY NEXT WEEK. /SEC AVIATION...06Z MODIS PASS SHOWED SOME FG IN THE VAN DUZEN RIVER VALLEY WITH MOSTLY CLEAR SKIES ACROSS REST OF CWA. EXPECT PERSISTENCE TO RULE THE DAY AS UPPER RIDGE PREVAILS ACROSS THE REGION. SOME PATCHY FG/STRATUS MAY DEVELOP ALONG THE COAST AROUND SUNRISE BUT WILL BE SHORT LIVED. VFR CONDITIONS WILL PREVAIL ACROSS THE REGION TODAY WITH SOME MVFR VSBY AROUND ROUND VALLEY DUE TO SMOKE FROM THE N PASS FIRE. && .EKA WATCHES/WARNINGS/ADVISORIES... CA...NONE. NORTHWEST CALIFORNIA COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 5 AM PDT SATURDAY PZZ450-455. GALE WARNING UNTIL 11 PM PDT THIS EVENING PZZ470. GALE WARNING UNTIL 3 PM PDT THIS AFTERNOON PZZ475. && $$ VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA FOLLOW US ON FACEBOOK AND TWITTER AT: HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV HTTP://WWW.TWITTER.COM/NWSEUREKA ______________________________________________________________________ --- Site: KEPZ --- --- Site: KEWX --- --- Site: KFFC --- --- Site: KFGF --- --- Site: KFGZ --- KFGZ - Reference: ['moisture across arizona with most sites (gps data from the suomi '] 526 FXUS65 KFGZ 141021 CCA AFDFGZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FLAGSTAFF AZ 320 AM MST SAT JUL 14 2012 .SYNOPSIS...A MOIST AND UNSTABLE AIRMASS WILL REMAIN OVER NORTHERN ARIZONA THROUGH SUNDAY. STORMS PRODUCING HEAVY RAINFALL ARE EXPECTED IN WESTERN ARIZONA THROUGH SATURDAY AND THEN MODERATE MONSOON CONDITIONS SUNDAY AND MONDAY. THUNDERSTORM CHANCES MOVE RAPIDLY EASTWARD ON TUESDAY AS DRY AND STABLE AIR MOVES INTO THE WESTERN HALF OF ARIZONA. && .DISCUSSION...A FLASH FLOOD WATCH REMAINS IN EFFECT FOR NORTHWEST AND WEST CENTRAL ARIZONA THROUGH 9 PM MST SATURDAY. DEEP SUBTROPICAL MOISTURE ACROSS ARIZONA WITH MOST SITES (GPS DATA FROM THE SUOMI NETWORK/NOAA/USGS/USACE/DOT/AND OTHERS) REPORTING 1"-2" OF PW MAINLY OVER THE WEST HALF OF AZ...THESE VALUES ARE ABOVE AVERAGE FOR THE TYPICAL MONSOON YEAR VALUES. WE HAVE SEVERAL FACTORS IN THE ATMOSPHERE THAT ARE WORKING WITH EACH OTHER TO MAKE THE WEATHER AT LEAST FOR SATURDAY RATHER UNIQUE. WE HAVE A SYNOPTIC NORTHERN STREAM TROUGH TO OUR NORTHWEST (CURRENTLY PRODUCING A LINE OF THUNDERSTORMS OVER SOUTHERN NEVADA AT THIS TIME) AND THEN A SUBTROPICAL SYSTEM CENTERED 50 TO 75 MILES WEST OF YUMA, AZ. BOTH OF THESE SYSTEM ARE PROVIDING AND WILL CONTINUE TO PROVIDE WEAK LIFT OVER THE WESTERN HALF OF ARIZONA TODAY AND SUNDAY...WITH THE STRONGEST LIFT BY LATE MORNING INTO LATE EVENING TODAY. THE LIFT WILL BE IN ASSOCIATION WITH THE SUBTROPICAL SYSTEM...PER MODEL SOLUTIONS AS THE SUBTROPICAL SYSTEM PHASES WITH NORTHERN STREAM SYSTEM AND MOVES NORTHEASTWARD TODAY OVER YAVAPAI (LATE MORNING TO MID AFTERNOON) AND COCONINO COUNTY (EARLY AFTERNOON INTO LATE EVENING). MODELS SUGGEST...AS THE SUBTROPICAL SYSTEM MOVES NORTHEAST TODAY A LOW TO MID LEVEL JET FORMS WITH WINDS PEAKING AT 25 TO 35 KNOTS. LAPSE RATES TODAY APPEAR TO RANGE FROM MOIST ADIABATIC TO LESS THAN DRY ADIABATIC ROUGHLY FROM 6.0 T0 7.5 DEG/KM...WITH THE LOW LEVEL JET RUNNING UPSLOPE INTO THE BRADSHAWS. THE INSTABILITY... AND THE HIGH PW VALUES WILL BE SUFFICIENT ENOUGH TO KICK OFF AN AREA OF THUNDERSTORMS LATER THIS MORNING OVER YAVAPAI COUNTY AND THEN LIFTING NORTHWARD ACROSS COCONINO COUNTY IN THE AFTERNOON. FLOW ALOFT AT CLOUD TOP LEVEL ABOVE THE THUNDERSTORMS IS FORECAST TO PEAK AT 40 KNOTS THIS WILL HELP ORGANIZE STORMS AND HELP PRODUCE SOME STORMS WITH LOCALLY HEAVY RAIN. GIVEN THE FLOW FROM THE LOW TO UPPER LEVELS...TRAINING STORMS WILL BE LIKELY (STORMS THAT FORM AND MOVE PARALLEL TO THE FLOW WITH NUMEROUS CELLS PRODUCING HEAVY RAIN OVER A LOCALIZED AREA). BY SUNDAY...THE FLOW ALOFT REMAINS FAIRLY STRONG AROUND 40 KNOTS ALONG WITH THE MAIN SYNOPTIC LOW PRESSURE TROUGH STILL OVER SOUTHERN CALIFORNIA. THE BEST MOISTURE HOWEVER WILL HAVE MOVED EAST INTO NAVAJO AND APACHE COUNTIES. THERE WILL BE SOME WEAK LARGE SCALE LIFT STILL WORKING ON THE ATMOSPHERE OVER THE WESTERN HALF OF THE STATE...SO SUNDAY STILL APPEARS TO BE A MODERATE MONSOON ACTIVITY DAY WITH SOME ORGANIZED THUNDERSTORMS PRODUCING LOCALIZED HEAVY RAIN AND HAIL. BY MONDAY...THE LOW PRESSURE TROUGH IS STILL OVER SOUTHERN CALIFORNIA...BUT WILL BEGIN TO LIFT NORTHEAST INTO THE GREAT BASIN...DRIER AIR WILL BEGIN TO BE PULLED INTO THE WESTERN HALF OF ARIZONA...SO THAT THE STORMS OVER THE WEST WILL TYPICALLY BE DRIER AND MORE WIDELY SCATTERED...IN THE EAST OVER NAVAJO AND APACHE COUNTIES THE STORMS WILL BE MORE NUMEROUS CAPABLE OF PRODUCING LOCALLY HEAVY RAIN. BY TUESDAY THE TROUGH WILL HAVE LIFT TO OUR NORTHEAST AND THE REGION WILL EXPERIENCE THE BEGINNING OF DRIER AND MORE STABLE AIR...TUESDAY THROUGH THURSDAY. && .AVIATION...FOR THE 12Z PACKAGE...ABUNDANT MOISTURE AND AN UNSTABLE AIRMASS WILL REMAIN OVER NORTHERN ARIZONA FOR THE NEXT 24 HOURS. TIL 17Z...WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST...WITH MVFR CONDITIONS WITH THE HEAVIER PRECIP. AFT 17Z...THUNDERSTORMS BECOME NUMEROUS IN COVERAGE ACROSS THE AREA. THE STRONGEST STORMS ARE EXPECTED WEST OF A LINE FROM PAGE TO BLACK CANYON CITY AND WILL HAVE IFR CONDITIONS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS. && .FIRE WEATHER... MOIST SOUTHERLY FLOW WILL CONTINUE THIS WEEKEND ACROSS ARIZONA. SCATTERED TO NUMEROUS THUNDERSTORMS ARE EXPECTED EACH AFTERNOON AND EVENING. THE STORMS WILL BE CAPABLE OF HEAVY RAINFALL...WITH WETTING RAINS PROBABLE OVER MUCH OF THE AREA. DAYTIME TEMPERATURES WILL RUN A FEW DEGREES BELOW NORMAL. MONDAY THROUGH WEDNESDAY...SOUTHWESTERLY FLOW ALOFT WILL DEVELOP OVER NORTHERN ARIZONA. AMPLE MOISTURE WILL LINGER ON MONDAY WITH CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS THE STATE. STARTING TUESDAY...A DRY AND STABLE AIRMASS MOVES INTO WESTERN THEN CENTRAL ARIZONA AND THUNDERSTORM CHANCES SHIFT TO EASTERN ARIZONA. && .FGZ WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FOR AZZ004>009-012-015-037-038 IN EFFECT THROUGH 9 PM MST SATURDAY. && $$ PUBLIC.........TC AVIATION.......DL FIRE WEATHER...DL FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT WEATHER.GOV/FLAGSTAFF ______________________________________________________________________ --- Site: KFSD --- --- Site: KFWD --- --- Site: KGGW --- KGGW - Reference: ['probably caused by differential snow cover. modis satellite shows'] 394 FXUS65 KGGW 160321 AFDGGW AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 821 PM MST THU NOV 15 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY... UPDATED FORECAST TO INCREASE TEMPERATURES TO THE SOUTH A LITTLE AND DECREASE THEM TO THE NORTH A LITTLE. CURRENT OBSERVATIONS ARE SHOWING TEMPERATURES ABOVE PREVIOUS FORECAST TO THE SOUTH. THIS IS PROBABLY CAUSED BY DIFFERENTIAL SNOW COVER. MODIS SATELLITE SHOWS THAT MOST OF THE SNOW HAS MELTED IN SOUTHERN ZONES...WHILE SNOW COVER IS STILL SIGNIFICANT TO THE NORTH. ALSO ADDED A MENTION OF PATCHY DENSE FOG AS SOME LOCAL AREAS HAVE OBSERVED VISIBILITY BELOW ONE QUARTER MILE. MARTIN PREVIOUS DISCUSSION... TONIGHT...MAIN FORECAST CHANGE HAS BEEN TO INCLUDE THE MENTION OF PATCHY FREEZING FOG IN THE VALLEYS BELOW 2500 FEET. THE 12Z MODELS REMAIN IN GOOD AGREEMENT THAT A SHORTWAVE TROUGH WILL PASS ACROSS OUR CWA TONIGHT ALONG WITH A WARM FRONT. HOWEVER...THE NAM BUFR SOUNDINGS SHOW A STRONG SHALLOW INVERSION HOLDING OVERNIGHT. THEREFORE...THINK THAT MOST OF THE WARMING WILL RIDE RIGHT OVER THE TOP OF THE SHALLOW COLD AIR...KEEPING THE COLD AIR TRAPPED AT THE SURFACE. THUS UPDATED THE FORECAST TO COOL VALLEY TEMPS...ESPECIALLY NORTH OF THE MILK AND MISSOURI RIVERS. WITH SNOW COVER IN PLACE...MOSTLY CLEAR SKIES...AND LIGHT WINDS EXPECT STRONG RADIATIONAL COOLING TO TAKE PLACE WHICH SHOULD LEAD TO ANOTHER ROUND OF PATCHY FREEZING FOG...MAINLY IN THE VALLEYS. MAINLY SUNNY SKIES ON FRIDAY WILL BEGIN TO BECOME FILTERED BY SOME HIGH CLOUDINESS AS THE NEXT SHORTWAVE APPROACHES THE CWA ACCOMPANIED BY HIGH AND MID LEVEL MOISTURE. SINCE CLOUD COVER WILL NOT BE A FACTOR UNTIL LATE IN THE DAY TEMPERATURES SHOULD STILL REBOUND NICELY AND EXPECT HIGHS NEAR 40 DEGREES IN THE NORTH. THE 12Z NAM BRINGS THE 850MB 8 DEGREE CELSIUS ISOTHERM AS FAR NORTH AS A LINE EXTENDING FROM WINNETT TO CIRCLE. AS A RESULT OF THIS POSSIBLE WARMING IT WOULD NOT BE SURPRISING TO SEE SOME OF THE SOUTHERN AND SOUTHWESTERN ZONES EXPERIENCE HIGHS INTO THE LOWER 50S...EVEN WITH THE SNOW PACK IN PLACE. OVERNIGHT FRIDAY NIGHT SKIES WILL CONTINUE TO CLOUD UP SO HAVE KEPT LOWS HIGHER AND FEEL THAT FOG WILL NOT BE A CONCERN. ON SATURDAY THE SHORTWAVE WILL BEGIN TO EXIT THE CWA LATE IN THE DAY SO EXPECT CLOUD COVER TO BEGIN TO GIVE WAY TO MORE SUNSHINE AND A HIGH TEMPERATURE DISTRIBUTION NOT ALL THAT DIFFERENT FROM FRIDAY. ALTHOUGH 850MB TEMPERATURES ARE A COUPLE OF DEGREES COOLER...WITH SOME ADDITIONAL SNOW MELT TAKING PLACE BY THIS TIME AND SOME INCREASING SUNSHINE THROUGHOUT THE DAY FEEL THAT THIS SEEMS REASONABLE. MALIAWCO/GILCHRIST .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY... THE EXTENDED PERIOD BEGINS SATURDAY NIGHT WITH NORTHEAST MONTANA UNDER A RIDGE. A PERSISTENT LOW IN THE GULF OF ALASKA SENDS A PACIFIC STORM AND COLD FRONT NUDGING INTO THE PAC-NW. THE STORM SENDS A TROUGH AND THE COLD FRONT OVER THE DIVIDE AROUND SUNDAY EVENING. THE DISTURBANCE BECOMES WEAKENED BY THE TIME IT GETS OVER THE PRAIRIE. THE GFS AND EC DIFFER SOMEWHAT IN TIMING AND LOCATION. THE GFS DOES BRING IN A NARROW BAND OF LIGHT RAIN SUNDAY NIGHT. THE GULF LOW ROTATES ANOTHER SHORTWAVE TROUGH INTO THE PAC-NW AROUND MID-WEEK. THE GFS AND EC ARE NOT IN AGREEMENT WITH TIMING. BUT SOMETIME AROUND WEDNESDAY OR THURSDAY THE NEXT FRONT PROGRESSES THROUGH THE REGION TO BRING A BETTER SHOT OF MOISTURE. WITH THE DROPPING TEMPERATURES THE AREA CAN EXPECT PRECIPITATION TO BEGIN WITH RAIN THAT COULD TRANSITION OVER TO SNOW BEFORE THE WEEKEND. HOLIDAY TRAVEL HAS THE POTENTIAL TO BE INTERFERED WITH IF THERE IS A WINTRY MIX. TEMPERATURES OVERALL...GUIDANCE SUGGESTS ABOVE NORMAL HIGHS WITH COOL NIGHTS. TEMPERATURES BEGIN NEAR NORMAL THEN TREND WARMER UNTIL THE COLD FRONT PASSES THROUGH AROUND MID-WEEK. THEN TEMPERATURES SHOULD TREND LOWER AROUND THE WEEKEND AS AN ARCTIC FRONT PUSHES SOUTH OUT OF CANADA. MAIN CHANGES WERE MADE TO UPDATE POPS/WX/SKY GRIDS BASED ON THE SLIGHTLY MORE PROGRESSIVE 12Z GFS AND EC MODELS. SCT PREVIOUS DISCUSSION... A LARGE UPPER TROUGH THAT STRETCHES FROM THE GULF OF ALASKA DOWN TO THE WASHINGTON OREGON COASTLINE WILL REMAIN IN PLACE THROUGH THE MIDDLE OF THE WEEK. PACIFIC MOISTURE WILL FLOW AROUND THE BASE OF THIS FEATURE AND INTO WESTERN MONTANA WHERE IT WILL BE RUNG OUT OVER THE NORTHERN ROCKIES UNTIL WEDNESDAY WHEN SOME OF THE MOISTURE WILL MAKE ITS WAY INTO EASTERN MONTANA. SOME THIS MOISTURE WILL ACCOMPANY A FAST MOVING SHORTWAVE ON SUNDAY ACROSS CENTRAL MONTANA AND MIGHT POSSIBLE MAKE IT TO OUR SW ZONES SUNDAY NIGHT. ADDED SLIGHT CHANCE POPS TO THE FORECAST SUNDAY NIGHT IN THE FORM OF RAIN SHOWERS AS TEMPERATURES SHOULD BE WARM ENOUGH TO KEEP THE PRECIPITATION LIQUID. EVERYONE ELSE ACROSS THE CWA WILL JUST SEE CLOUD COVER AS THIS SHORTWAVE PUSHES A DRY COLD FRONT ACROSS EASTERN MONTANA. MONDAY NIGHT AND BEYOND...THE PACIFIC NORTHWEST UPPER LEVEL TROUGH CONTINUES TO RE-ASSERT ITSELF AND SEEMS TO PUSH A MORE SIGNIFICANT INFLUENCE A BIT FURTHER EAST AND SOUTH. DECIDED TO ADD POPS FOR TUESDAY NIGHT THROUGH THURSDAY NIGHT AS ALL MODELS ARE SHOWING DIFFERING LEVELS OF QPF ACROSS THE EASTERN MONTANA. THERE IS A HINT OF SOMETHING COMING UP DAY 8 AND DAY 8 NIGHT WITH THE GOOD MODEL AGREEMENT ON QPF. THEY ARE ALL HINTING AT THE UPPER TROUGH BEING PUSHED OVER THE NORTHERN ROCKIES AS AN UPPER RIDGE BUILDS INTO THE GULF OF ALASKA. THE ECMWF HAS A MORE SHALLOW TROUGH LIKE FEATURE WHEN IT CROSSES THE NORTHERN ROCKIES. THE SUB ZERO 850 MB TEMPERATURES WILL REMAIN ALONG THE INTERNATIONAL BORDER. THE GFS/GEM HAVE THE TROUGH MUCH FARTHER SOUTH AS IT CROSSES THE NORTHERN ROCKIES WITH THE SUB ZERO 850MB TEMPERATURES AS FAR SOUTH AS NORTHERN WYOMING. SO WITH THIS IN MIND I SPLIT THE DIFFERENCE AND PUT IN A WINTRY MIX FOR THURSDAY AFTERNOON AND THURSDAY NIGHT. RSMITH && .AVIATION... VFR THROUGH ROUGHLY 1000Z THEN FREEZING FOG WILL GENERATE IFR VISIBILITIES FOR KGGW AND KOLF. AN UPPER RIDGE TONIGHT WILL ONCE AGAIN BRING MOSTLY CLEAR SKIES. MOISTURE CLOSE TO THE GROUND FROM MELTING SNOW COULD BRING ADDITIONAL FREEZING FOG LATE TONIGHT AND FRIDAY MORNING. THEN A WARM FRONT MOVING IN FROM THE SOUTHWEST WILL BRING IN CLOUD COVER BY FRIDAY EVENING...MINIMIZING THE CHANCE FOR FOG. WINDS WILL BE LIGHT AND OUT OF THE SOUTH TONIGHT SWITCHING TO THE SOUTHWEST TOMORROW. GAH/SCT && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WEATHER.GOV/GLASGOW ______________________________________________________________________ KGGW - Reference: ['the thursday 18z modis imagery shows the snow-pack to be'] 945 FXUS65 KGGW 162110 AFDGGW AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 210 PM MST FRI NOV 16 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY... SEASONALLY MILD CONDITIONS WILL PREVAIL THROUGH THE WEEKEND WITH THE FLOW ALOFT EITHER ZONAL OR TURNED SLIGHTLY SOUTHWEST. AN UPPER TROUGH NUDGING UP TO THE PAC-NW COAST WILL SEND RAIN INTO WESTERN WASHINGTON TODAY THROUGH SUNDAY. THIS TROUGH WILL EJECT A SHORTWAVE AND COLD FRONT EAST WHICH WILL WORK ITS WAY OVER THE DIVIDE SATURDAY NIGHT...THEN SPREAD OVER THE CENTRAL REGION ON SUNDAY...NOT QUITE MAKING IT INTO NORTHEAST MONTANA UNTIL AFTER SUNDAY. THE THURSDAY 18Z MODIS IMAGERY SHOWS THE SNOW-PACK TO BE WIDESPREAD OVER THE CWA. THE ONLY AREA WERE BARE GROUND IS APPEARING IS SOUTHERN PATCHES OF PETROLEUM AND JORDAN COUNTIES. THEREFORE TEMPERATURES WILL CONTINUE TO BE MODIFIED BY THE ALBEDO OF THE SNOW. TONIGHT...A WEAK SHORTWAVE EMBEDDED IN THE UPPER FLOW UNDERCUTS NORTHEAST MONTANA. THIS WAVE IS DRY. HOWEVER THE MAIN AFFECT WILL BE CLOUDS ASSOCIATED WITH THE WAVE. THAT WILL KEEP TEMPERATURES WARMER TONIGHT ESPECIALLY IN THE USUAL COLD AIR DRAINAGE AREAS AND LIMIT FOG FORMATION. SATURDAY/SATURDAY NIGHT...850MB AND 700MB WINDS BACK TO THE SOUTHWEST WHICH WILL TWEAK UP THICKNESS HEIGHTS AND 850MB TEMPERATURES SLIGHTLY. THE WARMER START AND PARTIAL CLEARING WILL NUDGE TMAX A BIT WARMER. SUNDAY...A LEE SURFACE TROUGH SHIFTS EAST BRINGING INCREASING CLOUDS WITH IT BY AFTERNOON...BUT NOT BEFORE TEMPERATURES AGAIN INCREASE SLIGHTLY. SCT .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY... SUNDAY NIGHT THROUGH MONDAY...OUR CWA WILL FIND ITSELF IN ZONAL SOUTHWESTERLY FLOW AS A SHORTWAVE APPROACHES. THE 12Z GFS HAS BACKED OFF ON QPF BUT THE 12Z ECMWF SHOWS CONSISTENCY BRINGING IN SOME PRECIPITATION TO OUR FORECAST AREA DURING THIS TIME. DUE TO THE UNCERTAINTY WILL LEAVE CURRENT FORECAST FOR PRECIPITATION IN PLACE. MONDAY NIGHT THROUGH THURSDAY...EXPECT SOME CLEARING ON MONDAY NIGHT AS THE SHORTWAVE EXITS OUR CWA. MODELS ARE IN EXCELLENT AGREEMENT ON AN UPPER RIDGE BUILDING IN FROM THE SOUTH DURING THIS PERIOD. THE GFS AND ECMWF BOTH WARM 850MB TEMPERATURES CONSIDERABLY ACROSS THE CWA AND WITH CONTINUING SNOW MELT ANTICIPATE THAT A WARM UP IS IN ORDER. SOME SNOW COVER LINGERING IN THE NORTH MAY KEEP TEMPERATURES COOLER THERE. EXPECT HIGHS TUESDAY THROUGH THURSDAY INTO THE 40S IN THE NORTH WITH 50S BECOMING MORE LIKELY ACROSS THE SOUTH. THE 12Z GFS BRINGS THE HIGHEST 850MB TEMPERATURES ACROSS OUR SOUTHWESTERN ZONES. IN FACT...850MB TEMPS REACH AS HIGH AS 11 DEGREES ALONG AND SOUTHWEST OF A LINE FROM NEAR SIDNEY TO SCOBEY. EVEN OUR FAR NORTHEASTERN ZONES APPROACH 10 DEGREES AT 850MB BUT DUE TO SNOW COVER IT WILL BE HARDER TO WARM UP AS MUCH THERE. SO HAVE KEPT WARMEST HIGHS ACROSS THE SOUTHWEST WHERE MID 50S ARE POSSIBLE TUESDAY AND WEDNESDAY AFTERNOON...BUT HAVE KEPT NORTHEASTERN ZONES IN THE MID 40S IN AREAS SUCH AS PLENTYWOOD AND POPLAR. MODELS BEGIN TO BREAK DOWN THE RIDGE ON THURSDAY AND WITH A SHORTWAVE ENTERING THE CWA THERE MAY BE ADDITIONAL CLOUDINESS AND PRECIPITATION AND SO HAVE KEPT TEMPERATURES COOLER. DUE TO THE LACK OF CONFIDENCE HERE WILL NOT MAKE MUCH CHANGE TO THE GOING PRECIPITATION PART OF THE FORECAST. THURSDAY NIGHT THROUGH SATURDAY...THERE IS UNCERTAINTY IN THIS PART OF THE EXTENDED PERIOD. THE 12Z GFS DGEX AND GEM ALL ARE AGGRESSIVE IN BREAKING DOWN THE RIDGE AND USHERING IN SOME ARCTIC AIR INTO OUR CWA THURSDAY NIGHT AND FRIDAY. MEANWHILE...THE ECMWF IS NOT AS PROGRESSIVE WITH THE RIDGE BREAKING DOWN AND USHERING IN MUCH COLDER AIR. DUE TO THE LACK OF CONFIDENCE HAVE COOLED TEMPERATURES SOME THURSDAY NIGHT FRIDAY DURING THE DAY...PARTICULARLY ACROSS THE NORTHEAST...BUT FUTURE SHIFTS WILL NEED TO WATCH FOR MODEL CONSISTENCY AND TRENDS. REGARDLESS... EXTENDED FORECAST MODELS SUGGEST ANOTHER RIDGE BUILDS IN FOR NEXT WEEKEND MEANING ANY COOL DOWN WOULD LIKELY BE SHORT LIVED. MALIAWCO/GILCHRIST && .AVIATION... MAINLY VFR. A MID AND HIGH LEVEL BKN-OVC CEILING CAN BE EXPECTED OVERNIGHT TONIGHT INTO SATURDAY AFTERNOON. SOUTHWEST WINDS AT KGDV AND KSDY WILL QUICKLY DECREASE AROUND SUNSET. OTHERWISE WINDS WILL GENERALLY BE LIGHT AND VARIABLE AT LESS THAN 06 KTS. SOME PATCHY IFR FOG MAY AGAIN DEVELOP IN THE RIVER BOTTOMS...BUT AT THIS TIME IT IS NOT EXPECTED TO IMPACT ANY OF THE TERMINALS. GILCHRIST/MALIAWCO && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WEATHER.GOV/GLASGOW ______________________________________________________________________ --- Site: KGID --- --- Site: KGJT --- --- Site: KGLD --- --- Site: KGRB --- KGRB - Reference: ['just n of sue where modis stlt imagery indicated lake surface'] 906 FXUS63 KGRB 271955 AFDGRB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 255 PM CDT MON AUG 27 2012 .SYNOPSIS...DRY AND VERY WARM WEATHER EXPECTED THIS WEEK...WITH THE NEXT CHANCE FOR RAIN HOLDING OFF UNTIL AT LEAST THE WEEKEND. PRETTY TYPICAL UPPER PATTERN FOR LATE SUMMER...WITH THE MAIN WESTERLIES PULLED WAY N ACRS SRN CANADA. UPR RIDGE OUT NR THE WEST COAST WL BUILD/EXPAND EWD ACRS THE AREA DURING THE WEEK. NOT GETTING A REAL CLEAR PICTURE ON THE EVOLUTION OF THE PATTERN LATE IN THE FCST PERIOD AND BEYOND...BUT IT SEEMS LIKELY WESTERLIES WL SAG SWD INTO THE CONUS AGAIN...WITH LNGWV TROF POSSIBLY TRYING TO GET RE-ESTABLISHED OVER THE E. THE PATTERN WL BE A VERY WARM AND DRY ONE FOR MOST OF THE FCST PERIOD...WITH SIGNIFICANTLY ABV NORMAL TEMPS AND LITTLE PROSPECT FOR SIG PCPN. PCPN CHCS MAY START TO INCR LATE IN THE PERIOD AS COOL FRONT SAGS SWD INTO THE AREA...THOUGH THAT DOES NOT REALLY HAVE THE LOOK OF A GOOD PCPN PRODUCER EITHER. && .SHORT TERM...TNGT/TUE. QUIET WX EXPECTED. SOME FG WL PROBABLY FORM AGAIN TNGT. BUT IT SHOULD NOT BE AS WIDESPREAD AS THIS MORNING...AND THE DENSE FG WL LIKELY BE CONFINED TO LOCALIZED FOG BANKS IN LOW-LYING AREAS AND NR STREAMS AND RIVERS. WL CARRY AS PATCHY FG IN THE FCST. CLR SKIES AND LGT WINDS SUPPORTED TAKING TEMPS A LITTLE BLO THE LOWER GUID VALUES...ESP IN THE CLIMATOLOGICAL COOL SPOTS. 850 MB TEMPS TUE WL BE SIMILAR TO TDA...SO STAYED CLOSE TO PERSISTENCE FOR MAX TEMPS MOST AREAS. THE EXCEPTION WL BE THE LAKESHORE. SINCE WE WON/T MIX INTO NWLY FLOW ALOFT TOMORROW...LAKE BREEZE WL WORK INLAND DURING THE AFTN. SO EDGED TEMPS DOWN LAKESIDE...ESP FM MTW- JUST N OF SUE WHERE MODIS STLT IMAGERY INDICATED LAKE SURFACE TEMPS HAD FALLEN INTO THE LOWER 60S DUE TO UPWELLING. .LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. AN UPPER LEVEL RIDGE OVER THE PLAINS WILL GIVE WAY TO ZONAL FLOW OVER THE GREAT LAKES REGION FOR THE LATTER HALF OF THIS WEEK. THIS WILL RESULT IN A PERIOD OF DRY AND MUCH WARMER THAN NORMAL WEATHER THROUGH THE END OF THE WORK WEEK. SOME LOCATIONS SEE NEW RECORD HIGHS ON THURSDAY. A FRONTAL BOUNDARY APPROACHING FROM THE NORTH IS EXPECTED TO BRING ONLY A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE WEEKEND SINCE LOW LEVEL MOISTURE IS LACKING AND THE BEST UPPER DYNAMICS SHOULD REMAIN NORTH OF THE STATE. A COOLING TREND CAN BE EXPECTED...WITH HIGHS FALLING TO NEAR NORMAL BY NEXT MONDAY. HOWEVER...THERE CONTINUES TO BE PLENTY OF UNCERTAINTY IN THE FORECAST AS THE WEEKEND APPROACHES DUE TO THE UNKNOWN PATH OF ISAAC. && .AVIATION...FOR 18Z TAF ISSUANCE. VFR CONDITIONS PREVAIL ACRS THE AREA NOW AND WL CONT INTO TNGT. STILL LOOKS TO BE ENOUGH LINGERING LOW-LEVEL MOISTURE FOR MIFG TO FORM LATE TNGT. COVERAGE OF THE FG SHOULD NOT BE AS GREAT AS IT WAS THIS MORNING...BUT VSBYS WL PROBABLY BE AFFECTED ENOUGH IN SOME AREAS TO WARRANT INCLUSION AS TEMPO GROUP IN RHI/CWA/GRB/AUW TAFS. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SKOWRONSKI/MG ______________________________________________________________________ KGRB - Reference: ['.marine...glerl surface water temperature analyses and modis stlt'] 429 FXUS63 KGRB 240856 AFDGRB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 356 AM CDT WED OCT 24 2012 .SYNOPSIS...WARM AND VERY MOIST TDA AND TNGT...THEN TURNING COLDER. LNGWV TROF OVER WRN NOAM WL AMPLIFY AND SHIFT E THE NEXT SEVERAL DAYS. BUT WITH VERY BLOCKY PATTERN DOWNSTREAM OVER THE ATL...THE RIDGE OVER ERN NOAM WL SHARPEN SIGNIFICANTLY BUT BASICALLY REMAIN LOCKED IN PLACE. THEN DURING THE LATTER PART OF THE PERIOD...A BROAD LOW-AMPLITUE RIDGE WL BUILD NR THE WEST COAST...WHILE THE TROF/RIDGE COMBINATION OVER ERN NOAM BASICALLY EVOLVE INTO THE WRN LEG OF THE ATL BLOCK. WARM AND VERY MOIST AIR WL REMAIN ACRS THE AREA INTO THU...THEN TEMPS WL DROP BACK TO A LITTLE BLO NORMAL FOR THE REST OF THE FCST PERIOD. STG COLD FRONT DRIVING INTO THE VERY MOIST AIRMASS WL SUPPORT A SIG PCPN EVENT TNGT INTO THU...WITH ONLY SCT LGT PCPN AT MOST AFTER THAT. && .SHORT TERM...TDA/TNGT/THU. OVERALL...GOING FCST IN PRETTY GOOD SHAPE. WL TWEAK THE POPS BASED ON A CONSENSUS OF THE TIMING OF THE ARRIVAL OF THE FRONT ON THE LASTEST GUIDANCE. GIVEN THE AVAILABLE MOISTURE AND THE STRENGTH OF THE INCOMING DYNAMICS...IT/S NOT AN AUTOMATIC THAT WE CAN DISMISS THE SVR THREAT JUST BECAUSE THIS IS LATE OCTOBER. THE NAM FCST SOUNDINGS FOR CENTRAL WI FOR LATE THIS AFTN WERE VERY IMPRESSIVE IN TERMS OF SVR POTENTIAL...WITH CONSIDERABLE CAPE AND SUFFICIENT SHEAR. HODOGRAPH WAS SOMEWHAT LOOPED...THOUGH NOT AS SWEPT OUT AS IDEAL FOR TORNADIC STORMS. BUT THE NAM SOUNDINGS SEEMED TO BE A WORST- CASE OUTLIER. PROGGED SFC TEMPS WERE PROBABLY A LITTLE TOO WARM. MORE IMPORTANTLY...THE VAST MAJORITY OF THE SREF MEMBERS HAD WARMER TEMPS IN THE 800-700 MB LAYER...EFFECTIVELY CAPPING THE INSTABILITY. THAT CAP WAS TOTALLY ABSENT ON THE NAM. GIVEN SOME ISENT LIFT AND ADDED CONVERGENCE IN THE VICINITY OF THE WARM FRONT LIFTG INTO THE AREA...SOME CAPPING COULD BE OVERCOME. IT/S JUST NOT CLEAR IF THERE WL BE ENOUGH FORCING. PLUS...BACKING OF THE UPR FLOW AHEAD OF THE MAIN TROF WL LIKELY CARRY CONVECTION THAT FIRES BACK OVER THE FRONTAL SFC NEWD MORE TOWARD N-C WI...WHERE THE ATM WON/T BE AS UNSTABLE. WL DETAIL CONDITIONAL NATURE OF THE SVR RISK IN THE HWO. THE OVERALL SITN DESCRIBED ABV WL CONT INTO TNGT. STORMS WL SPREAD FARTHER N AND E OVERNIGHT. BUT THE ATM WL BE MORE STABLE THERE...SO SVR THREAT WL GENERALLY DECR TO THE N AND E...AND WITH TIME. STORMS MAY NOT MAKE IT INTO E-C WI UNTIL MID-DAY THU. CARRIED LOW POPS UP UNTIL THEN JUST IN CASE SOMETHING GETS GOING A LITTLE FARTHER E. SECOND SIG FCST ISSUE IS THE FG. DON/T QUITE HAVE THE WIDESPREAD VERY LOW VSBYS WE WERE EXPECTING. BUT STILL PLENTY OF OB SITES BLO 1SM. AND SINCE VSBYS TYPICALLY EDGE DOWN ARND DAYBREAK...WL LET THE ADVISORY RUN INTACT. LARGE SCALE ADVECTION WL DOMINATE TEMPERATURE CHGS THE NEXT 36 HRS. BUILT 3-HOURLY TEMP GRIDS BASED ON ROBUST BLEND OF GUID PRODUCTS...THEN TOOK MAX/MIN GRIDS FM THOSE. .LONG TERM...THU NGT THRU NEXT TUE. MAIN FCST ISSUE THRU THE UPCOMING WEEKEND WL BE THE MOVEMENT OF AN UPR TROF FROM THE NRN/ CNTRL PLAINS NEWD THRU THE WRN GREAT LAKES AND EVENTUALLY CLOSING OFF TO AN UPR LOW WELL TO OUR NORTH. A BROAD LONGWAVE TROF TO BE LEFT ACROSS THE CNTRL CONUS WHICH WL PROVIDE COOL/DRY AIR TO NE WI. THE MEAN FLOW IS FCST TO BECOME MORE ZONAL NEXT WEEK WHICH WOULD ALLOW TEMPS TO WARM CLOSER TO NORMAL AND BRING THE NEXT CHC OF PCPN AROUND TUE. SINCE THE CDFNT TO STILL BE IN THE PROCESS OF EXITING THE REGION THU EVENING...WL NEED TO LINGER POPS PRIMARILY IN THE EAST. THAT BEING SAID...CLEARING SKIES SHOULD QUICKLY OVERSPREAD THE AREA LATER THU EVENING/OVERNIGHT AS AN INFLUX OF DRIER AIR AND STRONG SUBSIDENCE TO SCOUR OUT THE CLOUDS. THE THING THAT WL GET PEOPLE'S ATTENTION BY FRI MORNING IS THE COOL TEMPS AS 8H TEMPS DROPO TO AROUND -5C BY DAYBREAK. EXPECT TO SEE MIN TEMPS IN THE MID TO UPR 20S N-CNTRL WI...MID 30S E-CNTRL WI. AN AREA OF HI PRES OVER THE PLAINS IS FCST TO EDGE EWD THRU THE UPR MIDWEST TOWARD WI ON FRI. PLENTY OF CAA IN PLAY WITH 8H TEMPS IN THE -4 TO -8C RANGE. THIS COOL AIR ALOFT...COMBINED WITH DAYTIME HEATING...SHOULD CREATE ENUF INSTABILITY (STEEPENING MID- LEVEL LAPSE RATES) TO SUPPORT THE DEVELOPEMENT OF FAIR WEATHER CUMULUS. TOO DRY FOR ANY PCPN TO DEVELOP...BUT MORE CLOUDS FOR THE AFTERNOON HOURS. MAX TEMPS TO BE MORE NOVEMBER-LIKE WITH READINGS STRUGGLING TO REACH 40 DEGS NORTH...GENERALLY LWR TO MID 40S ELSEWHERE. THE HI PRES IS FCST TO MOVE CLOSER TO THE WRN GREAT LAKES FRI NGT WITH A CONTINUATION OF DRY AIR ON NW WINDS. MOST OF NE WI SHOULD SEE MOSTLY CLEAR SKIES THRU THE NIGHT WITH TWO POSSIBLE EXCEPTIONS. WINDS JUST ABOVE THE SFC MAY VEER ENUF TO THE NORTH TO POSSIBLY BRING LK EFFECT CLOUDS INTO N-CNTRL WI AS WELL AS ALONG THE LK MI SHORELINE. EVEN WITH SOME LK CLOUDS AROUND...IT WL STILL BE A COOL NGT OVER NE WI WITH MIN TEMPS SETTLING INTO THE MID 20S N-CNTRL... MID TO UPR 20S CNTRL...TO THE MID 30S NEAR LK MI. MDLS CONT TO SHOW AS THE HI PRES FINALLY REACHES THE GREAT LKS...IT IS FCST TO START WEAKENING DUE TO SHORTWAVE ENERGY MOVING THRU THE DEVELOPING CNTRL CONUS LONGWAVE TROF. STILL EXPECT TO SEE A MIX OF SUN AND CLOUDS ON SAT WITH TEMPS CONTINUING TO RUN 5 TO 10 DEGS BLO NORMAL. BY THE TIME WE GET TO SUNDAY...THIS UPR TROF IS PROGGED TO HAVE REACHED THE GREAT LKS WITH A PREDOMINANT NW FLOW ALOFT OVER WI. TYPICALLY...THERE WOULD BE AN EMBEDDED SHORTWAVE SOMEWHERE WITHIN THIS NW FLOW...BUT THE MDLS HINT AT A WEAK SHORTWAVE PASSING WELL TO OUR SOUTH. DO EXPECT MORE IN THE WAY OF CLOUDS ON SUNDAY...BUT WITHOUT A SIGNIFICANT TRIGGER NEARBY...HAVE KEPT SUNDAY DRY WITH TEMPS COMPERABLE TO SAT. ANOTHER AREA OF HI PRES IS FCST TO BUILD SWD FROM WRN ONTARIO INTO THE WRN GREAT LKS SUNDAY NGT INTO MON. DEPENDING ON WHERE THE RDG SETS UP...WL NEED TO WATCH LK EFFECT ALONG LK MI AS WINDS COULD TURN N-NE. IF THIS LK EFFECT DOES NOT OCCUR...DO NOT SEE ANY OTHER FEATURE THAT COULD TRIGGER ANY PCPN AS THE NEXT PRONOUNCED SHORTWAVE TROF TO STILL BE SITUATED OVER THE NRN PLAINS. PLENTY OF QUESTIONS REMAIN BEYOND NEXT MON WITH REGARDS TO THE MDLS GETTING A HANDLE ON THE REMAINS OF TROPICAL STORM 'SANDY'. IF THIS SYSTEM GETS PULLED TOWARD NEW ENGLAND...IT WL SLOW THE PROGRESS OF OTHER WEATHER SYSTEMS ACROSS THE CONUS INCLUDING THE SHORTWAVE/ACCOMPANIED CDFNT HEADED TOWARD WI MON NGT/TUE. FOR NOW...HAVE FOLLOWED A CONSENSUS SOLUTION WHICH WOULD BRING A SLGT CHC OF SHWRS INTO THE FCST AREA ALTHO CONFIDENCE IS LOW. && .AVIATION...FOR THE 12Z TAF ISSUANCE. VSYBS NOT QUITE AS UNIFORMLY LOW AS EXPECTED...BUT STILL PRETTY MUCH IFR AND BLO ACRS THE AREA. WL PROBABLY GET FOG TO THICKEN SOME ARND DAYBREAK. CONDITONS SHOULD IMPROVE FM S-N DURING THE MORNING...THOUGH IT WL BE A SLOW PROCESS. && .MARINE...GLERL SURFACE WATER TEMPERATURE ANALYSES AND MODIS STLT PASSES FM A COUPLE DAYS AGO INDICATED THAT COLDER WATER HAD UPWELLED JUST OFF THE KEWAUNEE/MANITOWOC COUNTY SHORELINE AREAS. WITH A SLY FLOW OF AIR WITH SFC DWPTS AOA 60F CONTG INTO THU... WOULD EXPECT DENSE FOG OVER THE LAKE AND PORTIONS OF THE BAY...AT LEAST AT TIMES. SO WL RUN THE MARINE FG ADVISORY UNTIL THE SCHEDULED FROPA THU AFTN. SLY WINDS WL INCR TNGT. WAVES OVER THE LAKE SHOULD EASILY REACH SC.Y CRITERIA...AND WINDS MAY REACH AS WELL. WL HOLD OFF ON ADDING THAT HEADLINE NOW TO KEEP FOCUS ON THE MORE IMMEDIATE THREAT OF THE DENSE FOG...BUT WL PROBABLY EVENTUALLY NEED TO POST SC.Y. && .GRB WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR WIZ005- 010>013-018>022-030-031-035>040-045-048>050-073-074. && $$ SKOWRONSKI/KALLAS ______________________________________________________________________ KGRB - Reference: ['marine...glerl surface water temperature analyses and modis stlt'] 868 FXUS63 KGRB 241413 AFDGRB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 913 AM CDT WED OCT 24 2012 .UPDATE... DENSE FOG WAS GRADUALLY RELEASING ITS GRIP OVER THE AREA THIS MORNING. ANTICIPATE MOST OF THE HEADLINE WILL EXPIRE AT 10 AM...WITH THE EXCEPTION OF LOCATIONS TOWARD THE LAKESHORE. TDH && .PREV DISCUSSION...ISSUED AT 356 AM CDT WED OCT 24 2012... SYNOPSIS...WARM AND VERY MOIST TDA AND TNGT...THEN TURNING COLDER. LNGWV TROF OVER WRN NOAM WL AMPLIFY AND SHIFT E THE NEXT SEVERAL DAYS. BUT WITH VERY BLOCKY PATTERN DOWNSTREAM OVER THE ATL...THE RIDGE OVER ERN NOAM WL SHARPEN SIGNIFICANTLY BUT BASICALLY REMAIN LOCKED IN PLACE. THEN DURING THE LATTER PART OF THE PERIOD...A BROAD LOW-AMPLITUE RIDGE WL BUILD NR THE WEST COAST...WHILE THE TROF/RIDGE COMBINATION OVER ERN NOAM BASICALLY EVOLVE INTO THE WRN LEG OF THE ATL BLOCK. WARM AND VERY MOIST AIR WL REMAIN ACRS THE AREA INTO THU...THEN TEMPS WL DROP BACK TO A LITTLE BLO NORMAL FOR THE REST OF THE FCST PERIOD. STG COLD FRONT DRIVING INTO THE VERY MOIST AIRMASS WL SUPPORT A SIG PCPN EVENT TNGT INTO THU...WITH ONLY SCT LGT PCPN AT MOST AFTER THAT. SHORT TERM...TDA/TNGT/THU. OVERALL...GOING FCST IN PRETTY GOOD SHAPE. WL TWEAK THE POPS BASED ON A CONSENSUS OF THE TIMING OF THE ARRIVAL OF THE FRONT ON THE LASTEST GUIDANCE. GIVEN THE AVAILABLE MOISTURE AND THE STRENGTH OF THE INCOMING DYNAMICS...IT/S NOT AN AUTOMATIC THAT WE CAN DISMISS THE SVR THREAT JUST BECAUSE THIS IS LATE OCTOBER. THE NAM FCST SOUNDINGS FOR CENTRAL WI FOR LATE THIS AFTN WERE VERY IMPRESSIVE IN TERMS OF SVR POTENTIAL...WITH CONSIDERABLE CAPE AND SUFFICIENT SHEAR. HODOGRAPH WAS SOMEWHAT LOOPED...THOUGH NOT AS SWEPT OUT AS IDEAL FOR TORNADIC STORMS. BUT THE NAM SOUNDINGS SEEMED TO BE A WORST- CASE OUTLIER. PROGGED SFC TEMPS WERE PROBABLY A LITTLE TOO WARM. MORE IMPORTANTLY...THE VAST MAJORITY OF THE SREF MEMBERS HAD WARMER TEMPS IN THE 800-700 MB LAYER...EFFECTIVELY CAPPING THE INSTABILITY. THAT CAP WAS TOTALLY ABSENT ON THE NAM. GIVEN SOME ISENT LIFT AND ADDED CONVERGENCE IN THE VICINITY OF THE WARM FRONT LIFTG INTO THE AREA...SOME CAPPING COULD BE OVERCOME. IT/S JUST NOT CLEAR IF THERE WL BE ENOUGH FORCING. PLUS...BACKING OF THE UPR FLOW AHEAD OF THE MAIN TROF WL LIKELY CARRY CONVECTION THAT FIRES BACK OVER THE FRONTAL SFC NEWD MORE TOWARD N-C WI...WHERE THE ATM WON/T BE AS UNSTABLE. WL DETAIL CONDITIONAL NATURE OF THE SVR RISK IN THE HWO. THE OVERALL SITN DESCRIBED ABV WL CONT INTO TNGT. STORMS WL SPREAD FARTHER N AND E OVERNIGHT. BUT THE ATM WL BE MORE STABLE THERE...SO SVR THREAT WL GENERALLY DECR TO THE N AND E...AND WITH TIME. STORMS MAY NOT MAKE IT INTO E-C WI UNTIL MID-DAY THU. CARRIED LOW POPS UP UNTIL THEN JUST IN CASE SOMETHING GETS GOING A LITTLE FARTHER E. SECOND SIG FCST ISSUE IS THE FG. DON/T QUITE HAVE THE WIDESPREAD VERY LOW VSBYS WE WERE EXPECTING. BUT STILL PLENTY OF OB SITES BLO 1SM. AND SINCE VSBYS TYPICALLY EDGE DOWN ARND DAYBREAK...WL LET THE ADVISORY RUN INTACT. LARGE SCALE ADVECTION WL DOMINATE TEMPERATURE CHGS THE NEXT 36 HRS. BUILT 3-HOURLY TEMP GRIDS BASED ON ROBUST BLEND OF GUID PRODUCTS...THEN TOOK MAX/MIN GRIDS FM THOSE. LONG TERM...THU NGT THRU NEXT TUE. MAIN FCST ISSUE THRU THE UPCOMING WEEKEND WL BE THE MOVEMENT OF AN UPR TROF FROM THE NRN/ CNTRL PLAINS NEWD THRU THE WRN GREAT LAKES AND EVENTUALLY CLOSING OFF TO AN UPR LOW WELL TO OUR NORTH. A BROAD LONGWAVE TROF TO BE LEFT ACROSS THE CNTRL CONUS WHICH WL PROVIDE COOL/DRY AIR TO NE WI. THE MEAN FLOW IS FCST TO BECOME MORE ZONAL NEXT WEEK WHICH WOULD ALLOW TEMPS TO WARM CLOSER TO NORMAL AND BRING THE NEXT CHC OF PCPN AROUND TUE. SINCE THE CDFNT TO STILL BE IN THE PROCESS OF EXITING THE REGION THU EVENING...WL NEED TO LINGER POPS PRIMARILY IN THE EAST. THAT BEING SAID...CLEARING SKIES SHOULD QUICKLY OVERSPREAD THE AREA LATER THU EVENING/OVERNIGHT AS AN INFLUX OF DRIER AIR AND STRONG SUBSIDENCE TO SCOUR OUT THE CLOUDS. THE THING THAT WL GET PEOPLE'S ATTENTION BY FRI MORNING IS THE COOL TEMPS AS 8H TEMPS DROPO TO AROUND -5C BY DAYBREAK. EXPECT TO SEE MIN TEMPS IN THE MID TO UPR 20S N-CNTRL WI...MID 30S E-CNTRL WI. AN AREA OF HI PRES OVER THE PLAINS IS FCST TO EDGE EWD THRU THE UPR MIDWEST TOWARD WI ON FRI. PLENTY OF CAA IN PLAY WITH 8H TEMPS IN THE -4 TO -8C RANGE. THIS COOL AIR ALOFT...COMBINED WITH DAYTIME HEATING...SHOULD CREATE ENUF INSTABILITY (STEEPENING MID- LEVEL LAPSE RATES) TO SUPPORT THE DEVELOPEMENT OF FAIR WEATHER CUMULUS. TOO DRY FOR ANY PCPN TO DEVELOP...BUT MORE CLOUDS FOR THE AFTERNOON HOURS. MAX TEMPS TO BE MORE NOVEMBER-LIKE WITH READINGS STRUGGLING TO REACH 40 DEGS NORTH...GENERALLY LWR TO MID 40S ELSEWHERE. THE HI PRES IS FCST TO MOVE CLOSER TO THE WRN GREAT LAKES FRI NGT WITH A CONTINUATION OF DRY AIR ON NW WINDS. MOST OF NE WI SHOULD SEE MOSTLY CLEAR SKIES THRU THE NIGHT WITH TWO POSSIBLE EXCEPTIONS. WINDS JUST ABOVE THE SFC MAY VEER ENUF TO THE NORTH TO POSSIBLY BRING LK EFFECT CLOUDS INTO N-CNTRL WI AS WELL AS ALONG THE LK MI SHORELINE. EVEN WITH SOME LK CLOUDS AROUND...IT WL STILL BE A COOL NGT OVER NE WI WITH MIN TEMPS SETTLING INTO THE MID 20S N-CNTRL... MID TO UPR 20S CNTRL...TO THE MID 30S NEAR LK MI. MDLS CONT TO SHOW AS THE HI PRES FINALLY REACHES THE GREAT LKS...IT IS FCST TO START WEAKENING DUE TO SHORTWAVE ENERGY MOVING THRU THE DEVELOPING CNTRL CONUS LONGWAVE TROF. STILL EXPECT TO SEE A MIX OF SUN AND CLOUDS ON SAT WITH TEMPS CONTINUING TO RUN 5 TO 10 DEGS BLO NORMAL. BY THE TIME WE GET TO SUNDAY...THIS UPR TROF IS PROGGED TO HAVE REACHED THE GREAT LKS WITH A PREDOMINANT NW FLOW ALOFT OVER WI. TYPICALLY...THERE WOULD BE AN EMBEDDED SHORTWAVE SOMEWHERE WITHIN THIS NW FLOW...BUT THE MDLS HINT AT A WEAK SHORTWAVE PASSING WELL TO OUR SOUTH. DO EXPECT MORE IN THE WAY OF CLOUDS ON SUNDAY...BUT WITHOUT A SIGNIFICANT TRIGGER NEARBY...HAVE KEPT SUNDAY DRY WITH TEMPS COMPERABLE TO SAT. ANOTHER AREA OF HI PRES IS FCST TO BUILD SWD FROM WRN ONTARIO INTO THE WRN GREAT LKS SUNDAY NGT INTO MON. DEPENDING ON WHERE THE RDG SETS UP...WL NEED TO WATCH LK EFFECT ALONG LK MI AS WINDS COULD TURN N-NE. IF THIS LK EFFECT DOES NOT OCCUR...DO NOT SEE ANY OTHER FEATURE THAT COULD TRIGGER ANY PCPN AS THE NEXT PRONOUNCED SHORTWAVE TROF TO STILL BE SITUATED OVER THE NRN PLAINS. PLENTY OF QUESTIONS REMAIN BEYOND NEXT MON WITH REGARDS TO THE MDLS GETTING A HANDLE ON THE REMAINS OF TROPICAL STORM 'SANDY'. IF THIS SYSTEM GETS PULLED TOWARD NEW ENGLAND...IT WL SLOW THE PROGRESS OF OTHER WEATHER SYSTEMS ACROSS THE CONUS INCLUDING THE SHORTWAVE/ACCOMPANIED CDFNT HEADED TOWARD WI MON NGT/TUE. FOR NOW...HAVE FOLLOWED A CONSENSUS SOLUTION WHICH WOULD BRING A SLGT CHC OF SHWRS INTO THE FCST AREA ALTHO CONFIDENCE IS LOW. MARINE...GLERL SURFACE WATER TEMPERATURE ANALYSES AND MODIS STLT PASSES FM A COUPLE DAYS AGO INDICATED THAT COLDER WATER HAD UPWELLED JUST OFF THE KEWAUNEE/MANITOWOC COUNTY SHORELINE AREAS. WITH A SLY FLOW OF AIR WITH SFC DWPTS AOA 60F CONTG INTO THU... WOULD EXPECT DENSE FOG OVER THE LAKE AND PORTIONS OF THE BAY...AT LEAST AT TIMES. SO WL RUN THE MARINE FG ADVISORY UNTIL THE SCHEDULED FROPA THU AFTN. SLY WINDS WL INCR TNGT. WAVES OVER THE LAKE SHOULD EASILY REACH SC.Y CRITERIA...AND WINDS MAY REACH AS WELL. WL HOLD OFF ON ADDING THAT HEADLINE NOW TO KEEP FOCUS ON THE MORE IMMEDIATE THREAT OF THE DENSE FOG...BUT WL PROBABLY EVENTUALLY NEED TO POST SC.Y. && .AVIATION...FOR THE 12Z TAF ISSUANCE. VSYBS NOT QUITE AS UNIFORMLY LOW AS EXPECTED...BUT STILL PRETTY MUCH IFR AND BLO ACRS THE AREA. WL PROBABLY GET FOG TO THICKEN SOME ARND DAYBREAK. CONDITONS SHOULD IMPROVE FM S-N DURING THE MORNING...THOUGH IT WL BE A SLOW PROCESS. && .GRB WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR WIZ005- 010>013-018>021-030-031-035>039-045-048-049-073-074. DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR WIZ022-040-050. && $$ ______________________________________________________________________ --- Site: KGRR --- KGRR - Reference: ['16z poes sounding near rqb shows moisture almost up to the 700 mb '] 797 FXUS63 KGRR 071934 AFDGRR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 240 PM EST SAT JAN 7 2012 LATEST UPDATE...ALL BUT AVIATION... .SYNOPSIS...(240 PM EST SAT JAN 7 2012) LOW PRESSURE OVER SOUTHERN QUEBEC WILL CONTINUE TO TRACK EASTWARD AWAY FROM THE GREAT LAKES REGION. MEANWHILE A LARGE AREA OF HIGH PRESSURE ACROSS THE CANADIAN PRAIRIES AND THE UPPER PLAINS STATES WILL BUILD INTO MICHIGAN. THIS FAIR WEATHER SYSTEM WILL ACT TO KEEP THE TEMPERATURES ABOVE NORMAL INTO EARLY NEXT WEEK. A WEAK COLD FRONT WILL SLIP THROUGH THE AREA ON MONDAY...BUT IT WILL BE FOLLOWED BY ANOTHER HIGH PRESSURE SYSTEM. && .SHORT TERM...(240 PM EST SAT JAN 7 2012) (TONIGHT THROUGH MONDAY NIGHT) HIGH PRESSURE WILL BE BUILDING INTO LOWER MI THROUGH SUNDAY. THIS SYSTEM WILL KEEP THE WEATHER RELATIVELY DRY. LOWER CLOUDS COVERING SOUTHWEST LOWER MI WILL GRADUALLY DIMINISH AS WE LOSE THE DAYTIME HEATING. THERE STILL COULD BE A FEW FLURRIES MAINLY UP AROUND TUSTIN AS THE DGZ WAS CLIPPING THE TOPS OF THE LOWER CLOUDS. LATEST IR IMAGERY SHOWS CLOUD TOP TEMPS OF AROUND -15 DEG C NORTH OF RQB. 16Z POES SOUNDING NEAR RQB SHOWS MOISTURE ALMOST UP TO THE 700 MB LEVEL. WHILE IT IS SHOWN THAT WE LOSE THE LOWER CLOUDS...HIGHER CLOUDS UP AROUND 300 MB MOVE OVERNIGHT. THEN FOR SUNDAY WEAK WARM AIR ADVECTION DEVELOPS. THIS SHOULD LIMIT THE RISK FOR ANY LOWER CLOUD FORMATION ACROSS AT LEAST SOUTHERN LOWER MI. WITH LIGHT WINDS AND SOME SUN ALONG WITH 925 MB TEMPS ONLY -4 DEG C...HIGH TEMPERATURES WILL CLIMB BACK TO ABOVE NORMAL LEVELS...GENERALLY IN THE MID TO UPPER 30S. A WEAKENING COLD FRONT PUSHES EASTWARD THROUGH LOWER MI ON MONDAY. THIS FEATURE SHOULD NOT LEAD TO ANY PRECIPITATION AS THERE IS ROUGHLY 5K TO 10K FT OF DRY AIR BELOW THE CLOUD BASES UP AROUND 10K FT. && .LONG TERM...(240 PM EST SAT JAN 7 2012) (TUESDAY THROUGH SATURDAY) MAIN WX STORY IN THE LONG TERM CONTINUES TO BE THE RETURN OF MUCH COLDER AIR TO LWR MI AND POTENTIAL FOR SIGNIFICANT LAKE EFFECT SNOW LATE IN THE WEEK. H8 TEMPS WILL BE DOWN TO -14 TO -16 C BY THURSDAY EVENING... IN A WEST TO WNW FLOW PATTERN FAVORABLE FOR POTENTIALLY SIGNIFICANT LAKE EFFECT SNOW. THE FCST IS BECOMING A LITTLE MORE UNCERTAIN BEGINNING FRIDAY. 00Z ECMWF KEPT COLD AIR LOCKED IN THROUGH FRIDAY... WHEREAS 12Z GFS GUIDANCE SHOWS A SFC RIDGE BUILDING IN WITH H8 TEMPS ALREADY BACK UP TO -10 TO -12C BY FRIDAY EVENING. THIS HAS IMPLICATIONS ON WHETHER LAKE EFFECT SNOW WILL CONTINUE TO GO RATHER STRONG THROUGH THE DAY FRIDAY OR WHETHER SNOW SHOWERS MAY ALREADY BEGIN TO TAPER OFF LATE FRIDAY AS GFS GUIDANCE WOULD SUGGEST. AT THIS TIME WE WILL KEEP SNOW SHOWERS IN THE FCST THURSDAY THROUGH FRIDAY... WITH HIGHEST POPS MAINLY WEST OF US-131. REGARDING THE WEATHER TUESDAY AND WEDNESDAY... UNSEASONABLY MILD/DRY DRY WX TO CONTINUE TUESDAY. THE OVERALL MEDIUM RANGE GUIDANCE CONSENSUS CONTINUES TO SUGGEST THAT LOW PRESSURE OVER THE TN VALLEY REGION WEDNESDAY WILL TRACK NE TO THE MID ATLANTIC REGION WEDNESDAY NIGHT... KEEPING SYNOPTIC PCPN SE OF LWR MI. HOWEVER THE SAME FCST CONCERNS ELUDED TO BY THE PREVIOUS SHIFT ARE STILL THERE FOR MIDWEEK... THAT IF THE SOUTHERN STREAM SYSTEM WERE TO TRACK FURTHER NORTH AND IF THE NORTHERN STREAM WAVE IS FASTER AND MERGES WITH THE SOUTHERN STREAM... THAT THIS WOULD YIELD A FURTHER NNW TRACK OF THE SFC LOW. THE MOST LIKELY OUTCOME FAVORS A TRACK FAR ENOUGH SE THAT SYNOPTIC PCPN WOULD MISS LWR MI WEDNESDAY... BUT IT IS NOTED THAT 12Z GFS GUIDANCE DOES CLIP OUR SE FCST AREA WITH SOME LIGHT PCPN WEDNESDAY WHICH WOULD PROBABLY BE IN THE FORM OF RAIN. && .AVIATION...(1240 PM EST SAT JAN 7 2012) MVFR TO NEAR MVFR CONDITIONS ANTICIPATED THIS AFTERNOON WITH CIGS OF 2500-3500 FT AGL. NW SFC WINDS WILL GUST TO NEAR 20 KTS AT TIMES THROUGH LATE AFTERNOON. SHOULD START TO SEE SOME GRADUAL CLEARING OVERNIGHT AS SFC RIDGING BUILDS IN... RESULTING IN MAINLY VFR CONDITIONS OVERNIGHT THRU 18Z SUN. && .MARINE...(240 PM EST SAT JAN 7 2012) GUSTY NORTHWEST WINDS AND COLD AIR ADVECTION WARRANT THE SMALL CRAFT ADVISORY. AS WE GO THROUGH THE OVERNIGHT PERIOD WINDS AND WAVES WILL BE DIMINISHING. THE PRESSURE GRADIENT REMAINS LOW THROUGH SUNDAY. HOWEVER ON MONDAY A WESTERLY WIND WILL INCREASE AND HEADLINES WILL LIKELY BE NEEDED. && .HYDROLOGY...(240 PM EST SAT JAN 7 2012) BELOW NORMAL PRECIPITATION AMOUNTS THROUGH THE PERIOD COMBINED WITH ABOVE NORMAL TEMPERATURES WILL MEAN LITTLE OR NO IMPACTS ON THE AREA RIVERS THROUGH THE PERIOD. THE WARMER THAN NORMAL TEMPERATURES WILL LESSEN THE RISK FOR ICE RELATED ISSUES. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...SMALL CRAFT ADVISORY ENTIRE NEARSHORE INTO TONIGHT. && $$ SYNOPSIS: MJS SHORT TERM: MJS LONG TERM: LAURENS AVIATION: LAURENS MARINE: MJS HYDROLOGY: MJS ______________________________________________________________________ --- Site: KGSP --- KGSP - Reference: ['recent goes...and one modis...visible images indicated a '] 661 FXUS62 KGSP 221949 AFDGSP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 249 PM EST SAT DEC 22 2012 .SYNOPSIS... DRY HIGH PRESSURE WILL DRIFT OFFSHORE LATE SUNDAY. A SURFACE LOW WILL MOVE WEST OF THE MOUNTAINS ON MONDAY. A STRONGER LOW WILL FOLLOW A SIMILAR TRACK ON TUESDAY. HIGH PRESSURE FROM CANADA WILL SETTLE IN ON FRIDAY BRINGING SLIGHTLY COOLER TEMPERATURES. && .NEAR TERM /THROUGH SUNDAY/... AT 2 PM...TEMPERATURES EAST OF THE MTNS HAVE WARMED A LITTLE MORE THAN EXPECTED...WITH VALUES COMMON IN THE 50S EAST OF THE MTNS. DEWPOINTS REMAIN IN THE SINGLE DIGITS TO TEENS...RESULTING IN RH VALUES IN THE TEENS TO L20S. I WILL KEEP A FIRE DANGER STATEMENT IN EFFECT FOR THE NC PIEDMONT...FOOTHILLS...AND EAST FACING SLOPES UNTIL 6 PM. RECENT GOES...AND ONE MODIS...VISIBLE IMAGES INDICATED A THIN SNOWPACK ACROSS THE WESTERN UPSLOPE AREAS OF THE NC MTNS. AREA WEB CAMS THAT INSOLATION HAS MELTED THE SNOW ON ROADS...PARKING LOTS...AND SIDEWALKS. CLEAR SKY COVER...DECREASING WINDS...AND A DRY AIR MASS SHOULD RESULT IN STEADY COOLING AFTER SUNSET. HOWEVER...H85 TEMPS RISE SLIGHTLY OVERNIGHT...SUPPORTING A WEAK INVERSE LAPSE RATES. BY MORNING...TEMPERATURES MAY RANGE FROM THE L20S WITHIN THE MTNS VALLEYS TO UPPER 20S ACROSS THE RIDGES...FOOTHILLS...AND PIEDMONT. THE FREEZING TEMPERATURES SHOULD RESULT IN PATCHES OF BLACK ICE WHERE MELT WATER REMAINS ON THE ROAD. I WILL ISSUE A SPS TO HIGHLIGHT THE SLICK CONDITIONS FOR THE AREAS WITH SNOW COVER. ON SUNDAY...WEAK LOW PRESSURE BEGINS TO FORM OVER THE ARKLATX REGION...SUPPORTING RETURN FLOW ACROSS THE SOUTHERN APPALACHIANS. MILD LLVL THICKNESSES AND MORNING INSOLATION SHOULD RESULT IN STEADILY WARMING TEMPERATURES AFTER SUNRISE. A BLEND OF MOS INDICATES THAT HIGH TEMPERATURES ARE FORECAST TO RANGE FROM THE LOW TO MID 50S WITHIN THE MTN VALLEYS TO U50S EAST. DEWPOINTS MAY RISE THROUGH THE DAY ON SW WINDS...BUT RH VALUES MAY REMAIN AROUND CRITICAL VALUES DURING THE HEAT OF THE AFTERNOON. OTHERWISE...THE FORECAST WILL FEATURE INCREASING HIGH CLOUDS ORIGINATING FROM THE ARKLATX LOW. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... AS OF 210 PM SATURDAY...A SHORT WAVE WILL CROSS THE REGION LATE IN THE DAY ON MONDAY. LOW PRESSURE ASSOCIATED WITH THE WAVE WILL LIFT WELL WEST OF THE MOUNTAINS...BUT THE REGION WILL BE UNDER STRONG LLVL WARM ADVECTION. THE ECMWF...CANADIAN AND UKMET ALL HAVE WIDESPREAD QUARTER TO HALF INCH RAIN AMOUNTS OVER THE FORECAST AREA CHRISTMAS EVE. THE NAM IS A LITTLE DRIER...THOUGH THE SREF ALSO HAS CATEGORICAL POPS SOUTH OF I-40. I/VE INCREASED POPS TO LIKELY ACROSS THE FORECAST AREA DURING THE DAY ON MONDAY...WITH AN AREA OF CATEGORICAL POPS ACROSS THE SRN ESCARPMENT OF THE BLUE RIDGE. THIS IS AN INCREASE FROM WHAT WE HAD BEFORE...BUT BASED ON CURRENT TRENDS I/D IMAGINE IT/S STILL A LITTLE TOO LOW. THERE MAY BE SOME COOL AND DRY AIR TRAPPED IN THE NC MTN VALLEYS AT THE START OF THE PCPN EVENT MONDAY MORNING...BUT WITH WARM H8 TEMPS AND SKIES CLOUDING UP EARLY SUNDAY EVENING...I DON/T SEE WET-BULBS BEING LOW ENOUGH FOR ANYTHING OTHER THAN RAIN ON MONDAY. THE MAV MOS IS COOLER ON MONDAY OWING TO THE HEAVIER PCPN IN THAT MODEL...AND THAT/S WHAT I USED IN THE GRIDS...ALBEIT WITH A FEW TWEAKS. THE SFC FRONT IS LIKELY TO HANG UP OVER THE FOOTHILLS AND MOUNTAINS MONDAY NIGHT. I/M NOT SURE HOW MUCH CLEARING WE/LL ACTUALLY SEE...ESPECIALLY DOWN ACROSS UPSTATE SC AND NE GA. I DID GO WITH A PERIOD OF PARTIAL CLEARING LATE MONDAY AND MONDAY NIGHT...BUT CONFIDENCE IS CLEARING IS NOT HIGH. ON TUESDAY A STRONGER SHORT WAVE WILL LIFT ACROSS THE LOWER MS RIVER VALLEY. THE NAM LOOKS TOO WEAK WITH THIS FEATURE AND I/VE SIDED WITH THE GFS/ECWMF WHICH ARE ABOUT 10 MB DEEPER WITH THE SFC LOW THAN THE NAM. PARTIAL THICKNESSES ARE MUCH TOO WARM FOR ANYTHING OTHER THAN RAIN. THERE IS SOME MID-LEVEL FRONTOGENESIS THAT CROSSES THE FA WELL AHEAD OF THE WAVE TUE AFTN. THIS IS CAUSING QUITE A SPREAD IN THE ONSET TIME OF PCPN IN THE MODELS. I/VE GONE A LITTLE SLOWER THAN SOME OF THE NEIGHBORS...BUT THERE IS STILL QUITE A BIT OF QUESTION AS TO WHETHER WE CAN EEK OUT A DRY CHRISTMAS MORNING WITH THIS PATTERN. EVEN WITH A MILD AIRMASS...THE CLOUDY SKIES WILL HOLD MAX TEMPS AROUND NORMAL LEVEL FOR THE DAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 110 PM SATURDAY...THE GLOBAL MODELS REMAIN IN GOOD AGREEMENT IN THE EVOLUTION OF A MILLER B SCENARIO ACROSS THE SOUTHEAST AND MID-ATLANTIC TUE NIGHT AND WEDNESDAY...WITH WIDESPREAD RAIN EXPECTED TO OVERSPREAD THE AREA BEGINNING CHRISTMAS EVENING. WITH THE PRIMARY SURFACE LOW TRACKING WEST OF THE APPALACHIANS...AND SYNOPTIC SURFACE HIGH IN AN UNFAVORABLE LOCATION FOR CLASSICAL COLD AIR DAMMING... WINTRY WEATHER DOES NOT APPEAR TO BE A MAJOR CONCERN. HOWEVER...THE LATEST RUNS OF THE ECMWF ARE SLIGHTLY MORE AGGRESSIVE WITH LOWERING THICKNESS VALUES IN RESPONSE TO IN SITU CAD DEVELOPMENT TUE NIGHT. IT IS NOT OUT OF THE QUESTION THAT TEMPS COULD DROP TO/BELOW FREEZING ALONG THE EASTERN ESCARPMENT AFTER PRECIP ONSET...AND BECOME LOCKED THERE FOR A FEW HOURS...AS IS SOMETIMES THE CASE WITH IN SITU EVENTS. A MENTION OF -FZRA WILL BE CARRIED ACROSS A VERY SMALL PORTION OF THE CWFA WED MORNING (MAINLY THE NRN MTNS AND FOOTHILLS). PRECIP IS EXPECTED TO END ACROSS THE AREA BY WED EVENING...THE ONLY EXCEPTION BEING ACROSS THE TENN BORDER COUNTIES...WHERE SCT/NUMEROUS ACCUMULATING NW FLOW SNOW SHOWERS SHOULD PERSIST THROUGH WED NIGHT INTO EARLY THURSDAY. A TRANSITION TO A MORE PHASED/HIGH AMPLIFIED FLOW IS EXPECTED BY THE END OF THE PERIOD...WITH A MAJOR/PROGRESSIVE LONG WAVE TROUGH EXPECTED TO TAKE SHAPE ACROSS THE CENTRAL CONUS BY THE END OF THE WEEK. THE GLOBAL MODELS SUGGEST THE ATTENDANT FRONTAL SYSTEM WILL BEGIN AFFECTING THE EASTERN STATES BY NEXT WEEKEND...AND SMALL POPS HAVE BEEN INCLUDED ACROSS OUR AREA BEGINNING EARLY SATURDAY MORNING. A GUIDANCE CONSENSUS SUGGESTS THERMAL PROFILES WILL ONCE AGAIN BE TOO WARM TO SUPPORT MUCH IN THE WAY OF WINTRY PRECIP OVER OUR AREA. HOWEVER...IF LIGHT PRECIP BEGINS AS EARLY AS SUGGESTED BY THE LATEST GUIDANCE...ENOUGH COLD AIR MAY REMAIN IN PLACE ACROSS PORTIONS OF THE HIGH TERRAIN TO SUPPORT A BRIEF PERIOD OF FREEZING RAIN. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... AT KCLT AND ELSEWHERE...NO CEILING OR VISIBILITY RESTRICTIONS THROUGH THE 18Z TAFS. THE MAIN CONCERN THROUGH THE FORECAST PERIOD WILL BE WIND DIRECTION AND SPEEDS. THE LATEST SFC ANALYSIS INDICATES THAT A LEE TROF WAS LOCATED OVER THE PIEDMONT OF THE CAROLINAS. THE TROF WILL LIKELY SUPPORT WSW WINDS EAST OF THE MTNS...WITH NNW WINDS AT KAVL AND KHKY. KHKY SHOULD BACK TO WSW LATER THIS AFTERNOON. SPEEDS EAST OF THE MTNS SHOULD FAVOR VALUES BETWEEN 5 TO 10 KTS. KAVL MAY REMAIN GUSTY UNTIL WINDS DECOUPLE TOWARD SUNSET. OVERNIGHT...A BROAD PRESSURE FIELD IS EXPECTED WITHIN THE LEE TROF...WINDS WILL BECOME AND REMAIN LIGHT TO VARIABLE TO CALM THIS EVENING AND OVERNIGHT. LITTLE CHANGE IN THE PATTERN EXPECTED SUNDAY...SPEEDS WILL FAVOR VALUES NEAR 5 KTS. A FEW HIGH CLOUDS MAY ARRIVE ACROSS THE WESTERN CAROLINAS BY LATE SUNDAY MORNING. OUTLOOK...AN ACTIVE PATTERN ON TAP FOR THE UPCOMING WEEK. THE NEXT SYSTEM IS EXPECTED TO BRING A QUICK SHOT OF CLOUDS/PRECIP ON MONDAY. THEN ANOTHER...STRONGER...SYSTEM IS EXPECTED TO AFFECT THE AREA TUESDAY NIGHT THRU WEDNESDAY. AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)... WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM && .FIRE WEATHER... OWING TO THE LACK OF WIND ON SUNDAY WE ARE NOT PLANNING TO ISSUE A FIRE DANGER STATEMENT FOR ANY PARTS OF THE WESTERN CAROLINAS OR NORTHEAST GEORGIA. AND IN THE CASE OF NE GA...WHERE A FIRE DANGER STATEMENT CAN BE ISSUED JUST BASED ON MINIMUM RH AND FUELS...THE RH VALUES ARE NOT PREDICTED TO FALL TO CRITICAL LEVELS. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...PAT NEAR TERM...NED SHORT TERM...MCAVOY LONG TERM...JDL AVIATION...NED FIRE WEATHER...MCAVOY ______________________________________________________________________ --- Site: KGYX --- --- Site: KHGX --- --- Site: KHNX --- --- Site: KHUN --- --- Site: KICT --- --- Site: KILM --- --- Site: KILN --- --- Site: KILX --- --- Site: KIND --- --- Site: KIWX --- --- Site: KJAN --- --- Site: KJAX --- --- Site: KJKL --- --- Site: KKEY --- KKEY - Reference: ['zones...patchy fog. a noaa-18 sst analysis depicts believable water'] 827 FXUS62 KKEY 121007 AFDKEY AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS NATIONAL WEATHER SERVICE KEY WEST FL 507 AM EST WED DEC 12 2012 .DISCUSSION...THE SOUTHERN STREAM OF A SPLIT FLOW UPPER-LEVEL JET EXTENDS FROM THE EASTERN PACIFIC...ACROSS CENTRAL MEXICO...AND ACCELERATES NORTHEASTWARD THROUGH THE NORTH CENTRAL GULF COAST. ABUTTED AGAINST THIS UPPER LEVEL PATTERN IS A DEEP ATLANTIC RIDGE...ROOTED IN THE CENTRAL NORTH ATLANTIC. FOR THE PAST SEVERAL DAYS...A PERSISTENT CONFLUENCE OF WARM AND MOIST AIR OF THE LOW LEVELS WITH MID-LATITUDE WEST SOUTHWESTERLIES HAS SET-UP RESIDENCE IN THE SOUTHEAST GULF OF MEXICO. ALONG THIS BOUNDARY...SEVERAL SYNOPTIC PERTURBATIONS HAVE SPARKED LARGE MCS COMPLEXES WHICH HAVE STREAMED INTO THE SOUTHWESTERN FLORIDA PENINSULA. THE FLORIDA KEYS HAVE REMAINED ON THE MUGGY SIDE OF THIS ACTIVITY...FREE FROM RAIN...WITH PERSPIRATION THE ONLY PRECIPITATION FALLING. .CURRENTLY...DEWPOINTS ARE IN THE LOW TO MID 70S THROUGHOUT THE KEYS...AND TEMPERATURES ARE REMARKABLY ALL NEAR 78F. SOUTHEASTERLY WINDS ARE 5 TO 10 MPH ALONG THE ISLANDS...AND JUST ABOVE 10 KNOTS AT THE C-MANS. A LARGE EXPANSE OF HEAVY RAIN SHOWERS WITH EMBEDDED THUNDERSTORMS CONTINUES OUTSIDE THE WESTERN CWA. .SHORT TERM (TODAY THROUGH FRIDAY)...A STRONG SHORTWAVE...CURRENTLY IN THE ARKLATEX...WILL SKIRT THE NORTHERN GULF COAST TODAY AND TONIGHT...FINALLY WEAKENING THE SOUTHWESTERN EDGE OF THE LOW LEVEL RIDGE AXIS. THE STALLED FRONTAL BOUNDARY IN NORTH CENTRAL FLORIDA AND THE PREFRONTAL TROUGH CLOSER TO HOME...WILL FINALLY BEGIN THEIR PUSH SOUTHEASTWARD. WINDS WILL WEAKEN PRIOR TO THE TROUGH PASSAGES...THEN ON THE BACKSIDE...THE NORTHEASTERLIES WILL REESTABLISH THEMSELVES AS HIGH PRESSURE BUILDS INTO THE SOUTHEAST UNITED STATES AND THE WESTERN ATLANTIC. WE HAVE DROPPED RAIN CHANCES TODAY TO ISOLATED/ SLIGHT CHANCE FOR THE MAJORITY OF THE CWA...AND KEPT SCATTERED/ CHANCE FOR TONIGHT AND TOMORROW. WE FEEL THE NORTHERLY SURGE AGAINST THE FORMIDABLE THETA-E GRADIENT WILL INTRODUCE AT LEAST A SCATTERED LINE OF SHOWERS STRADDLING THE 12Z TIME STEP. UNTIL THEN...TODAY...THE LOW LEVEL RIDGE AXIS WILL HOLD STRONG...LIMITING RAIN CHANCES. FOR TONIGHT...WE ADDED A WILD CARD TO THE SOUTHEASTERN GULF ZONES...PATCHY FOG. A NOAA-18 SST ANALYSIS DEPICTS BELIEVABLE WATER TEMPERATURES IN THE MID 60S NORTH OF THE MARQUESAS AND DRY TORTUGAS. GUIDANCE AGREES UPON LIGHT NORTHERLY WINDS WITH HIGH THETA-E ORIGINS...VERY NEAR THE COOLER SEA WATER TEMPERATURES. THUS...WE FEEL THERE IS A CHANCE FOR AN ADVECTIVE MARINE FOG IN ADVANCE OF THE STRONGER NORTHERLY WINDS. BY FRIDAY...TEMPERATURES WILL RETURN TO MORE NORMAL LEVELS...AND THE DEWPOINTS WILL TAKE ON MORE CONTINENTAL CHARACTERISTICS...DROPPING BACK INTO THE MID 60S. && .LONG TERM (FRIDAY NIGHT THROUGH TUESDAY)...CONDTIONS RETURN TO THEIR DECEMBER NORMALS THROUGH THE WEEKEND...NORTHEASTERLY WINDS...HIGHS IN THE UPPER 70S...AND LOWS NEAR 70. ON TUESDAY...THE SOUTHERLY WINDS BRIEFLY RETURN IN ADVANCE OF THE NEXT POTENTIAL AIR MASS CHANGE. GUIDANCE HAS HONED IN A MORE SIGNIFICANT COLD FRONT AROUND THE MIDDLE OF NEXT WEEK...UNTIL THERE IS MORE AGREEMENT...STATUS QUO WILL BE KEPT IN THE SENSIBLE WEATHER TRENDS. && .MARINE...A COLD FRONT DRAPED OVER CENTRAL FLORIDA WILL SLOWLY ADVANCE SOUTHWARD DOWN THE FLORIDA PENINSULA TODAY AND TONIGHT...THEN MOVING NEAR THE FLORIDA KEYS ON THURSDAY. HIGH PRESSURE WILL BUILD ACROSS THE MID ATLANTIC AND SOUTHEASTERN STATES THURSDAY THROUGH FRIDAY...THEN WEAKEN AND SLIDE OFFSHORE DURING THE UPCOMING WEEKEND. PATCHY FOG IS POSSIBLE IN THE VICINITY...AND NORTH OF...THE DRY TORTUGAS AND MARQUESAS TONIGHT. && .AVIATION...VFR CONDITIONS WILL LIKELY PREVAIL AT THE KEY WEST AND MARATHON TERMINALS THROUGH WEDNESDAY EVENING. THERE IS A LOW CHANCE FOR MVFR CIGS BASED AROUND 1500 FEET DURING THE PREDAWN TO MID MORNING HOURS...BUT THE PROBABILITIES ARE TOO LOW TO MENTION IN THE TAFS AT THIS POINT. ISOLATED SHOWERS WILL BE POSSIBLE ACROSS THE KEYS TODAY...BUT INDICATIONS ARE THAT THE MAIN ZONE OF ACTIVE CONVECTION WILL REMAIN BEYOND 30 MILES WEST OF KEY WEST...OVER THE SOUTHEASTERN GULF OF MEXICO. SURFACE WINDS WILL REMAIN FROM THE SOUTHEAST AT 7 TO 10 KNOTS. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...NONE. GM...NONE. && $$ PUBLIC/MARINE.........CLR AVIATION/NOWCASTS.....JACOBSON DATA COLLECTION.......ULRICH VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST ______________________________________________________________________ --- Site: KLBF --- --- Site: KLCH --- --- Site: KLIX --- --- Site: KLKN --- --- Site: KLMK --- --- Site: KLOT --- KLOT - Reference: ['also of note...on the modis and goes visible images today and this'] 413 FXUS63 KLOT 050227 AAA AFDLOT AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 927 PM CDT WED JUL 4 2012 .DISCUSSION... 925 PM CDT ONLY MINOR CHANGES MADE TO THE GOING FORECAST WITH CONDITIONS GENERALLY ON TRACK WITH THE FORECAST. THE HOT TEMPERATURES OF TODAY ARE SLOWLY FALLING ACROSS THE AREA WITH DEW POINTS INCHING UP A FEW DEGREES AS THE MIXING OF THE DAY SUBSIDED. HEAT INDEX READINGS IN CHICAGO REMAIN RIGHT AROUND 100 AT 9 PM...WITH MINIMUM VALUES ONLY EXPECTED TO BE IN THE MID 80S. LOWS IN THE LOWER 80S IN CHICAGO WITH LOW TO MID 70S IN OUTLYING AREAS ARE STILL FAVORED. IT IS POSSIBLE FOR SOME SHALLOW LIGHT FOG TRAPPED UNDERNEATH THE THERMAL INVERSION IN OUTLYING AREAS...AS 9 PM OBSERVATIONS AT RPJ OF 80 OVER 76 AND PNT OF 82 OVER 77 HINT AT. LOOKING AHEAD TO THURSDAY...A LAKE BREEZE REMAINS FAVORED IN LATEST GUIDANCE ASSESSMENT WITH WIND FLOW IN THE MIXED LAYER AROUND 5-8 KT LESS THAN TODAY. SIMILAR TO SE WI TODAY WHERE THE SYNOPTIC WINDS WERE SLIGHTLY LESS...THE LAKE BREEZE IS FAVORED TO INCH VERY SLOWLY INLAND AGAINST THE WEST SOUTHWEST WIND. MUCH OF THE LAKE COUNTIES STILL WILL BE SEEING HEAT INDEX READINGS NEAR 110 DUE TO BOTH THE LIMITED INLAND IMPINGEMENT AND THE FACT THE WIND SHIFT MAY BE LATE ENOUGH AFTER THE HIGHS ARE REACHED /HIGH AT ORD TODAY WAS EARLY AT 133 PM/. CONVECTIVE CHANCES ALONG THE LAKE BREEZE ARE SMALL...BUT ARE NON-ZERO. THERE IS SLIGHT COOLING IN THE MID-LEVELS FORECAST FROM THIS EVES RAOB READINGS. FORECAST MLCIN IS NEAR ZERO IN NORTHEAST IL. THE 04.18 NAM HAD THE CENTRAL MN SHORT WAVE IMPULSE TONIGHT DRIFTING OVER THAT AREA DURING THE LATE AFTERNOON...WHILE THE MOST RECENT NAM HAS TRENDED SLIGHTLY FASTER. IF THAT SLIGHT IMPULSE CAN INTERACT OVER THE LAKE BREEZE CONVERGENCE...IT MAY NEGATE ANY CIN FOR WIDELY SCATTERED BUT PROBABLY STRONG THUNDERSTORM DEVELOPMENT. ALSO OF NOTE...ON THE MODIS AND GOES VISIBLE IMAGES TODAY AND THIS EVENING WAS QUITE A BIT OF SMOKE IN THE DAKOTAS...NE...MN...AND IA. NAM PARCEL TRAJECTORIES FROM 20000 FT AND HIGHER INDICATE THIS AREA SHOULD DRIFT OVER THE AREA THURSDAY...ALTHOUGH IT MAY BE MORE DISPERSED. THERE WERE NO INDICATIONS OF VISIBILITY REDUCTIONS IN THOSE UPSTREAM AREAS TODAY AND THIS EVE...BUT IF THAT WERE TO SETTLE CLOSER TO THE TOP OF THE MIXED LAYER THURSDAY...SLIGHTLY MORE HAZE AND POTENTIALLY WORSE AIR QUALITY COULD DEVELOP. MTF && .PREV DISCUSSION... 445 PM CDT FORECAST FOCUS SQUARELY ON CONTINUATION OF INTENSE HEAT THROUGH FRIDAY. AN EXCESSIVE HEAT WARNING IS IN EFFECT FOR THE ENTIRE FORECAST AREA THROUGH 10 PM CDT FRIDAY. AIR TEMPERATURES CLIMBED TO 95 TO 102 ACROSS THE FA THIS AFTERNOON WITH HEAT INDEX NUMBERS UP TO 103 TO 108. NORTHEASTWARD EXTENSION OF THE 850KPA THERMAL RIDGE THAT STRETCHES ACROSS THE MID MO VALLEY TO THE UPPER MIDWEST TODAY IS TO BE SUPPRESSED A BIT TO THE S ACROSS SOUTHERN WI AND NORTHERN IL FOR THU AND FRI AS THE UPPER RIDGE OVER THE UPPER MIDWEST AND WESTERN ONTARIO GETS FLATTENED BY THE UPPER LOW TRACKING E OVER THE CANADIAN PRAIRIE. EXPECT MAX TEMPS ON THU THAT ARE A DEG OR TWO ABOVE TODAY/S...AND THEN FOR FRI AN ADDITIONAL DEG HIGHER OVER THU AT MOST LOCATIONS. WHILE A WEAK LAKE BREEZE IS EXPECTED TO DEVELOP TOMORROW AFTERNOON IT IS NOT EXPECTED TO MOVE MORE THAN MARGINALLY INLAND UNTIL LATE IN THE AFTERNOON AND EARLY EVENING SO ANY RELIEF WILL BE VERY LIMITED AND SHORT LIVED AS LIGHT SW LOW LEVEL FLOW PUSHES THE HOT AIR RIGHT BACK OUT OVER THE SHORE LINE BY LATER THU EVENING. TIMING OF COOL FRONT AND LAKE BREEZE DURING FRI COMPLICATES THINGS A BIT BUT FEEL THAT THE ACTUAL FRONT WILL REACH NORTHERN IL UNTIL VERY LATE FRI OR MORE LIKELY FRI NIGHT. WEAK W TO SW LOW LEVEL FLOW DURING FRI WILL LIKELY ALLOW A LAKE BREEZE TO PUSH INLAND BUT NOT ANTICIPATED UNTIL DURING THE LATER AFTERNOON-EARLY EVENING SO FRI WILL BE ANOTHER VERY HOT DAY ACROSS THE VAST MAJORITY OF THE FA WITH THE FAR NE CORNER OF IL LIKELY THE ONLY PART OF THE FA TO GET ANY REAL RELIEF UNTIL THE ACTUAL COOL FRONT DROPS ACROSS THE AREA. WITH MAX TEMPERATURES GENERALLY IN THE 100 TO 105 RANGE THU AND FRI THE LOWERING OF SURFACE DEW POINTS BACK UPPER 60S AND LOWER 70S PER GUIDANCE WILL KEEP HI NUMBERS UP IN THE 105-115 ACROSS MUCH OF THE AREA THU AND FRI AFTERNOONS. WITH OVERNIGHT HEAT INDEX NUMBERS ONLY FALLING TO AROUND 75 TONIGHT AND THU NIGHT EXCESSIVE HEAT WARNING CRITERIA FOR ALL OTHER COUNTIES SURROUNDING COOK WHICH HAS IT/S OWN SET FOR THE CITY WILL BE REACHED SO ADVISORY EXPANDED ACROSS THE ENTIRE AREA. HEAT AND HUMIDITY RESULT IN LARGE VALUES OF POTENTIAL INSTABILITY BUT LOW LEVEL FOCUS AND MID-UPPER DISTURBANCES LACKING THUS ONLY SLIGHT CHANCES OF ISOLATED TS IF ALL INGREDIENTS COME TOGETHER AT THE RIGHT TIME AT A PARTICULAR SPOT. THUS...POP NUMBERS TOO LOW FOR ANY MENTION OF EVEN SLIGHT CHANCE UNTIL FRI NIGHT WITH THE COOL FRONT MOVING INTO NORTHERN IL. MODELS NOT BULLISH WITH PUSHING THIS BOUNDARY FURTHER S SAT OR SUN SO WILL HAVE SLIGHT CHANCE TO LOW END CHANCE POPS GOING ALL OR PARTS OF THE FA FOR SAT THROUGH MON UNTIL BOUNDARY FINALLY GETS SHOVED ACROSS CENTRAL TO SOUTHERN IL TAKING LOW LEVEL MOISTURE POOLED ON EITHER SIDE OF IT OUT OF THE LOCAL FA. TRS && .CLIMATE... 925 PM CDT RECORDS... CHICAGO THU JUL 5 MAX 102 1911 MIN 82 1911 FRI JUL 6 MAX 99 1988 MIN 80 1977 ROCKFORD THU JUL 5 MAX 100 1911 MIN 77 1911 FRI JUL 6 MAX 102 1936 MIN 73 1948 THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 ON JULY 24 1934... AND FOR ROCKFORD IS 112 ON JULY 14 1936. FOR CHICAGO THE MOST CONSECUTIVE 100 DEGREE OR HIGHER DAYS IS THREE...JULY 3RD THROUGH 5TH OF 1911...AND ALSO AUGUST 4TH THROUGH 6TH OF 1947. FOR ROCKFORD THE MOST CONSECUTIVE 100 DEGREE OR HIGHER DAYS IS NINE...JULY 6TH THROUGH 14TH OF 1936. IZZI/TRS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * LAKE BREEZE POTENTIAL THURSDAY AFTERNOON/EVENING. BMD //DISCUSSION...UPDATED 00Z... NO SIGNIFICANT CONCERNS FOR THE REST OF THE EVENING AND OVERNIGHT HOURS. EXPECT THE AREA TO CONTINUE TO SIT BETWEEN AREA OF HIGH PRESSURE TO THE SOUTHEAST WITH SLOW MOVING AREA OF LOW PRESSURE OVER THE PLAINS. THIS LEAVES NORTHERN ILLINOIS AND NORTHWEST INDIANA UNDER WESTERLY FLOW. GRADIENT SHOULD BE A LITTLE WEAKER THURSDAY LEADING TO SOMEWHAT LIGHTER WIND SPEEDS. THIS SHOULD ALLOW A LAKE BREEZE TO DEVELOP...THOUGH THERE IS UNCERTAINTY AS TO HOW FAR INLAND IT WILL PUSH GIVEN THE OPPOSING WINDS. SHOULD IT MAKE IT ACROSS THE CHICAGO TERMINALS...WINDS WOULD SWITCH AROUND TO AN EASTERLY DIRECTION. ALSO WILL HAVE TO MONITOR CONVECTIVE CHANCES ALONG THE LAKE BREEZE. THERE SHOULD BE DECENT CONVERGENCE ALONG THE BOUNDARY AND SOUNDINGS INDICATE UNCAPPED ATMOSPHERE POINTING TO THE POTENTIAL FOR DEVELOPMENT ALONG THE BOUNDARY AND THEN MOVING SOUTHEAST. BMD //ORD AND MDW CONFIDENCE...UPDATED 00Z... * LOW CONFIDENCE IN LAKE BREEZE REACHING TERMINALS THURSDAY AFTERNOON/EVENING. BMD //OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z... FRIDAY...VFR. SATURDAY AND SUNDAY...VFR. CHANCE TSRA SATURDAY NIGHT INTO SUNDAY. MONDAY AND TUESDAY...VFR. BMD && .MARINE... 250 PM CDT A WEAK COLD FRONT HAS BECOME NEARLY STATIONARY OVER CENTRAL LAKE MICHIGAN THIS AFTERNOON...BUT WILL LIFT BACK NORTH TONIGHT AS LOW PRESSURE OVER THE EASTERN DAKOTAS AND CANADIAN PRAIRIES LIFTS TOWARD HUDSON BAY. THE LOW WILL CONTINUE EAST ACROSS HUDSON BAY THURSDAY AND THURSDAY NIGHT...WITH A COLD FRONT TRAILING ACROSS THE WESTERN LAKES REGION AND SLIDING SOUTH DOWN LAKE MICHIGAN AND SETTLING ACROSS THE SOUTH END BY EARLY FRIDAY. THE FRONT WILL SLOW BRIEFLY FRIDAY NIGHT AS A WEAK SURFACE WAVE RIPPLES EAST ALONG THE FRONT... WITH NORTHERLY FLOW THEN STRENGTHENING SATURDAY AS HIGH PRESSURE BUILDS ACROSS THE UPPER MIDWEST AND NORTHERN GREAT LAKES. WINDS WILL GENERALLY BE ON THE LIGHT SIDE OUTSIDE OF ANY THUNDERSTORM GUSTS UNTIL SATURDAY...WHEN THE TIGHTENING NORTHERLY GRADIENT AND PUSH OF SOMEWHAT COOLER AIR RESULTS IN NORTH-NORTHEAST WINDS INCREASING INTO THE 15-20 KT RANGE PERHAPS WITH A FEW GUSTS IN THE 20-25 KT RANGE SATURDAY INTO SATURDAY NIGHT. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...EXCESSIVE HEAT WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008- ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021- ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 10 PM FRIDAY. IN...EXCESSIVE HEAT WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 10 PM FRIDAY. LM...NONE. && $$ ______________________________________________________________________ --- Site: KLOX --- --- Site: KLSX --- --- Site: KLUB --- --- Site: KLWX --- --- Site: KLZK --- --- Site: KMAF --- --- Site: KMEG --- --- Site: KMFL --- --- Site: KMFR --- --- Site: KMHX --- --- Site: KMKX --- KMKX - Reference: ['towards the open waters. modis imagery shows lake surface temp'] 379 FXUS63 KMKX 092358 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 558 PM CST MON JAN 9 2012 .UPDATE...NO CHANGE AT THIS TIME. && .MARINE...EXTENDED SMALL CRAFT ADVY UNTIL 02Z. CHII2 GUSTING TO 37KTS WHICH LIES AT THE EDGE OF THE NEARSHORE ZONES. ALTHOUGH THE ANEMOMETER IS AROUND 60FT OFF THE LAKE SURFACE...THINK SOME STRONGER GUSTS TO 25 KNOTS STILL MAY OCCUR FOR A FEW MORE HOURS TOWARDS THE OPEN WATERS. MODIS IMAGERY SHOWS LAKE SURFACE TEMP AROUND 5C 3-5 MILES FROM SHORE. LINGERING STEEP LAPSE RATES IN THE LOW LEVELS WOULD CONTRIBUTE TO GUSTS TO 25 KNOTS. && .PREV DISCUSSION... /ISSUED 334 PM CST MON JAN 9 2012/ SHORT TERM... TONIGHT AND TUESDAY...FORECAST CONFIDENCE MEDIUM TO HIGH TIGHT PRESSURE GRADIENT WILL WEAKEN THIS EVENING...AS LOW PASSING WELL NORTH OF THE REGION MOVES AWAY. THUS...THE GUSTY SOUTHWEST WINDS SHOULD SUBSIDE BY SUNSET...WITH WINDS EVENTUALLY DECOUPLING LATER TONIGHT AS HIGH PRESSURE TRACKS TO THE SOUTH OF THE AREA. MOSTLY CLEAR SKIES ARE EXPECTED...WITH A FEW MID TO HIGH CLOUDS POSSIBLY MOVING THROUGH THE NORTHERN COUNTIES LATER TONIGHT INTO TUESDAY. OUTSIDE CHANCE OF LIGHT FOG IN LOW LYING AREAS WITH MOSTLY CLEAR SKIES AND WEAKENING WINDS...BUT LEFT OUT OF FORECAST DUE TO LOW CONFIDENCE WITH DRY AIRMASS OVERHEAD. WARM AIR ADVECTION WEAKENS SOMEWHAT TONIGHT INTO TUESDAY. SOME RADIATIONAL COOLING IS EXPECTED ACROSS THE AREA LATER TONIGHT WITH THE LIGHT WINDS AND MOSTLY CLEAR SKIES. LOWS IN THE MID 20S INLAND WITH UPPER 20S NEAR THE LAKE SEEM REASONABLE...THOUGH IT COULD BE A BIT COOLER IN LOW LYING AREAS. NEAR RECORD HIGHS IN THE LOWER 50S ARE FORECAST FOR TUESDAY...WITH WARM ADVECTION BOOSTING 925MB TEMPERATURES TO 4 TO 6 DEGREES CELSIUS ALONG WITH MO SUNNY SKIES. TUESDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE MEDIUM A LARGE POLAR TROUGH WILL DIG SEWD INTO THE NRN PLAINS TUE NT AND WED WHILE THE ASSOCIATED AREA OF LOW PRESSURE MOVES SEWD FROM MANITOBA CANADA TO LAKE SUPERIOR. THE COLD FRONT WILL NOT ARRIVE UNTIL AFTERNOON AND MOVE FROM NW TO SE ACROSS THE AREA. SINCE IT WILL BE AN ANAFRONT...SOME SUNSHINE SHOULD HELP PROVIDE ANOTHER MILD DAY FOR WED...LOWER 50S ARE FORECAST IN SE WI. BRISK NWLY WINDS AND STRONG COLD ADVECTION TO PREVAIL WED NT INTO THU. A WEAK NARROW BAND OF 850-700 MB FRONTOGENESIS WILL OCCUR AFTER FROPA AND AHEAD OF THE LARGE POLAR TROUGH. THIS WILL BRING A CHANCE OF LGT SNOW...MAINLY WED NT WITH BEST CHANCES IN ERN WI. ANY SNOW ACCUMULATIONS WOULD REMAIN UNDER AN INCH. TEMPS WILL RETURN TO MORE SEASONAL NORMALS FOR THU. LONG TERM... FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE LOW TO MEDIUM THE LARGE POLAR TROUGH OVER THE GREAT LAKES WILL MOVE NEWD ON FRI WITH DECREASING NW WINDS. THE MODELS DIFFER ON THE PLACEMENT AND STRENGTH OF A POTENTIAL ALBERTA CLIPPER FOR SAT...BUT IT WOULD LIKELY BE VERY WEAK WITH A SLIGHT CHANCE OF LGT SNOW CURRENTLY ONLY FORECAST OVER EAST CENTRAL WI. FOR SUNDAY AND MONDAY THE JET STREAM WILL RETURN TO MORE ZONAL FLOW WITH MODERATING TEMPERATURES. AVIATION/00Z TAFS/... VFR CONDITIONS EXPECTED THROUGH TUESDAY. GUSTY SOUTHWEST WINDS WILL LINGER UNTIL SUNSET ACROSS TAF SITES...WITH GUSTS UP TO 30 KNOTS POSSIBLE. WINDS WILL THEN GRADUALLY SUBSIDE TONIGHT...AS HIGH PRESSURE SLIDES SOUTH OF THE AREA. MOSTLY CLEAR SKIES ARE EXPECTED TONIGHT...WITH A FEW MID TO HIGH CLOUDS GRAZING THE TAF SITES LATE TONIGHT INTO TUESDAY. LIGHT AND VARIABLE WINDS WILL BECOME SOUTHWEST ON TUESDAY...WITH A FEW GUSTS TO 15 KNOTS OR SO POSSIBLE IN THE AFTERNOON. OUTSIDE CHANCE OF VFR TO BORDERLINE MVFR FOG AT MADISON AND KENOSHA LATE TONIGHT AND EARLY TUESDAY...BUT LEFT OUT OF TAFS DUE TO LOW CONFIDENCE WITHIN DRY AIRMASS. MARINE... SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 00Z TUESDAY ACROSS THE NEARSHORE WATERS. TIGHT PRESSURE GRADIENT AND GOOD LOW LEVEL MIXING OF WINDS SHOULD CONTINUE TO BRING FREQUENT SOUTHWEST WIND GUSTS TO AROUND 30 KNOTS. HIGHEST WAVES WOULD BE TOWARD THE OPEN WATERS GIVEN THE OFFSHORE FLOW. CONSIDERED EXTENDING THE SMALL CRAFT ADVISORY INTO THIS EVENING...BUT WIND GUSTS SHOULD BE BORDERLINE AT BEST...SO LEFT THE EXPIRATION TIME AT 00Z TUESDAY. SMALL CRAFT ADVISORY LEVEL WINDS ARE EXPECTED WEDNESDAY NIGHT THROUGH THURSDAY NIGHT ACROSS THE NEARSHORE WATERS. A STRONG COLD FRONT WILL MOVE THROUGH THE AREA LATE ON WEDNESDAY. BRISK NORTHWEST WINDS BEHIND THE FRONT WILL ENSUE WEDNESDAY NIGHT...LINGERING THROUGH THURSDAY NIGHT...WITHIN A TIGHT PRESSURE GRADIENT. GUSTS UP TO 30 KNOTS ARE POSSIBLE AT TIMES. HIGH WAVES ARE EXPECTED TOWARD THE OPEN WATERS WITH THE OFFSHORE FLOW. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 8 PM CST THIS EVENING FOR LMZ643>646. && $$ MBK ______________________________________________________________________ KMKX - Reference: ['modis images from today show lake sfc temps still around 5-6c'] 648 FXUS63 KMKX 110335 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 935 PM CST TUE JAN 10 2012 .UPDATE...WL NEED TO LOWER OVERNIGHT MINIMUMS MOST LOCATIONS AS CLEAR SKIES AND LIGHT WINDS HAVE ALLOWED TEMPS TO PLUMMET EARLY THIS EVENING. MOST AREAS SHOULD EXPERIENCE MORE FROST THAN FOG BUT WL ADD FOG MENTION INTO WI RVR VALLEY. 00Z NAM CONTINUES SLIGHT SWD TREND OF STRENGTHENING LOW PRESSURE OVER SRN LOWER MI THU AFTN AND NIGHT. THIS SCENARIO RESULTS IN A TIGHTER PRESSURE GRADIENT AND GUSTIER WINDS OVER SRN WI DURING THIS PD. HEADLINES LIKELY TO BE ISSUED EARLY WED. && .AVIATION/06Z TAFS/...PATCHY LIGHT FOG MAY DEVELOP EARLY THIS MORNING FOR SEVERAL HOURS AS TEMPS FALL TO NEAR OR BELOW THE SFC DEWPT. OTRW...EXPC VFR CONDITIONS FOR MOST OF THE FORECAST PERIOD. WL NEED TO BRING LOWER CIGS/VSBYS ASSOCD WITH -SN INTO KMSN AFT 06Z/12...AND INTO KMKE AFT 14Z/12 AS LOW PRESSURE STRENGTHENS OVER THE CENTRAL GTLAKES. && .MARINE...00Z NAM CONTINUES TREND OF INTENSIFYING SFC LOW PRESSURE FARTHER SOUTH OF LOWER MI THU AFTN AND THU NIGHT RESULTING IN TIGHT PRESSURE GRADIENT OVER LAKE MI INTO FRI. BUMPED UP WIND SPEEDS TO 20 TO 30 KNOTS DURING THIS PERIOD. SOME WIND GUSTS MAY REACH GALE WARNING LEVELS THU NIGHT INTO EARLY FRI DUE TO STEEP LOW LEVEL LAPSE RATES IN THE LOW LEVELS OF THE ATMOSPHERE. MODIS IMAGES FROM TODAY SHOW LAKE SFC TEMPS STILL AROUND 5-6C FROM THE EDGE OF THE NEAR SHORE WATERS TO MID-LAKE. && .PREV DISCUSSION... /ISSUED 324 PM CST TUE JAN 10 2012/ SHORT TERM... TONIGHT AND WEDNESDAY...FORECAST CONFIDENCE HIGH. QUIET WEATHER THROUGH WEDNESDAY AS WE AWAIT THE ARRIVAL OF A LOW PRESSURE SYSTEM BRINGING WIDESPREAD SNOW TO THE AREA LATE WEDNESDAY NIGHT THROUGH FRIDAY. EXPECTING CLEAR SKIES TONIGHT THROUGH AT LEAST WED MORNING BEFORE SOME MID AND HIGH CLOUDS WITH THE LOW REACH SOUTHERN WI WED AFTERNOON. TRIED TO CUT BACK IN FCST CLOUDS FOR WEDNESDAY... SINCE SATELLITE SHOWS VERY FEW CLOUDS AHEAD OF THIS SYSTEM UPSTREAM. WITH THE CLEAR SKIES WILL COME A SHALLOW COLD LAYER NEAR THE SURFACE ONCE AGAIN TONIGHT WITH RADIATIVE COOLING. WENT WITH CLOSE TO GFS MOS GUIDANCE...ON THE COOLER SIDE OF GUIDANCE...SINCE THE PAST SEVERAL NIGHTS HAVE DECOUPLED AND HAD MIN TEMPS LOWER THAN EXPECTED. TEMPS WILL INCREASE QUICKLY AGAIN WED MORNING. THERE IS UNCERTAINTY BETWEEN THE MODELS ON TIMING OF THE WIND SHIFT AND SFC COLD FRONT COMING THROUGH THE AREA ON WED...WITH THE GFS QUICKEST...MAKING IT INTO OUR NW FORECAST AREA AROUND 18Z... AND THE ECMWF/REGIONAL CANADIAN REACHING THE NW FORECAST AREA AROUND 00Z. WENT WITH COMPROMISE. EITHER WAY...THE MUCH COLDER AIR WITH THE PRECIP WILL NOT ARRIVE UNTIL THE LEADING 500MB VORT MAX AND FRONTOGENESIS GETS IN HERE WED NIGHT. THEREFORE...MAX TEMPS SHOULD BE ONLY SOMEWHAT COOLER THAN THEY WERE TODAY...RANGING FROM MID 40S IN NORTHWEST FORECAST AREA TO AROUND 50 IN MILWAUKEE/KENOSHA. VERY LIGHT WINDS OVER THE REGION WITHIN THE COLL BETWEEN THE APPROACHING LOW AND THE OTHER SFC LOW TO THE SOUTHEAST DURING THE DAY ON WEDNESDAY. THE LIGHT WINDS WITH THE WARMER AIR TEMPS AND COOL LAKE MICHIGAN WATER TEMPS IN THE UPPER 30S...A LAKE BREEZE SHOULD DEVELOP WED AFTERNOON. IF THIS HAPPENS TOO QUICKLY...THE FCST MAX TEMPS ARE TOO HIGH. WEDNESDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM THE MODELS CONTINUE TO SHOW A MORE DYNAMIC AND SNOWY SYSTEM FOR LATE WED NT THROUGH THU NT. A LARGE DIGGING POLAR TROUGH WILL MOVE FROM THE NRN PLAINS TO A LINE EXTENDING FROM MN TO OK BY 12Z THU. THE POLAR TROUGH WILL THEN LIFT NEWD...BECOMING NEGATIVE TILT AND CLOSED OFF WITH THE UPPER LOW MOVING ACROSS IL/IN TO THE ERN GREAT LAKES BY 12Z FRI. THE ASSOCIATED CYCLOGENESIS WILL DEVELOP OVER THE GREAT LAKES WITH A CONSENSUS OF MODELS PLACING THE LOW OVER LAKE HURON BY 00Z FRI. COLD FROPA WILL OCCUR WED NT WITH 850-700 MB FRONTOGENESIS AND PVA TO FOLLOW LATE WED NT INTO THU NT. THERE ALSO WILL BE SOME ISENTROPIC LIFT ON THE LEADING EDGE OF THE SYSTEM BEFORE COLD ADVECTION INCREASES. OVERALL...OMEGA AND LIFT IS CATEGORIZED AS MODERATE. THIS IS A LARGE STORM SYSTEM AND A CONSENSUS OF QPF GIVES AROUND 0.30 INCHES IN THE FAR WRN CWA TO 0.40 INCHES IN THE EAST AND NORTH. 1000-500 MB THICKNESSES...COBB TECHNIQUE...AND ROEBBERS NEURAL NETWORK ALL GIVE LIGHT SNOW RATIOS EVEN WITH 15 KT SFC WINDS...AS TROPOSPHERIC TEMPS BECOME VERY COLD. THIS YIELDS 5-6 INCHES OF SNOW OVER A 30 HOUR PERIOD. THERE WILL BE ENOUGH WIND FOR DRIFTING SNOW AND POSSIBLY SOME BLOWING SNOW BUT WIND GUSTS ARE TOO LOW FOR WIDESPREAD BLOWING SNOW AND GREATLY REDUCED VISIBILITIES. A WINTER WX ADVISORY WILL LIKELY BE NEEDED OVER THE ENTIRE CWA FOR THIS SNOW EVENT. A WORST CASE SCENARIO IS IF THE NAM IS CORRECT IN PLACING THE CYCLOGENESIS OVER LAKE MICHIGAN OR IN WRN LOWER MI. WINDS WOULD THEN GUST TO NEARLY 30 KTS OR MORE AND WINTER STORM WARNINGS MAY NEED TO BE CONSIDERED. THIS HOWEVER IS AN OUTLIER FOR NOW. THE LOW AND ASSOCIATED UPPER TROUGH WILL MOVE AWAY FOR FRI WITH VERY LGT SNOW POSSIBLY LINGERING IN THE EAST. HIGH TEMPS TO ONLY REACH THE TEENS AFTER MORNING LOWS IN THE SINGLE DIGITS. LONG TERM... SATURDAY THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM A WEAK ALBERTA CLIPPER IN NWLY FLOW ALOFT IS NOW PROJECTED TO TRACK SEWD ALONG THE MS RIVER VALLEY FOR SAT. THE LOCATION OF THIS FEATURE WILL LIKELY CONTINUE TO CHANGE BUT IT CURRENTLY IS TOO WEAK TO FORECAST SNOW. HIGH PRESSURE WILL THEN SETTLE OVER THE REGION FOR SAT NT INTO SUN AM. A STRONG AREA OF LOW PRESSURE WILL THEN MOVE EWD ACROSS SRN CANADA THROUGH EARLY NEXT WEEK WITH THE UPPER FLOW BECOMING MORE ZONAL. SLY FLOW AND WARM ADVECTION WILL THEN ENSUE SUN AFTERNOON INTO MON WITH A RETURN OF NORMAL TO ABOVE NORMAL TEMPS. THERE WILL BE SMALL CHANCES FOR LGT SNOW MON NT AS A SHORTWAVE TROUGH TRACKS ALONG THE OHIO RIVER VALLEY. OTHERWISE THE CANADIAN COLD FRONT WILL ARRIVE FOR TUE WITH A RETURN OF COLD TEMPS. AVIATION/00Z TAFS/...VFR THROUGH THE PERIOD. JUST SOME HIGH CLOUDS EXPECTED. A LAKE BREEZE IS POSSIBLE WED AFTERNOON AT MKE AND MAYBE EVEN ENW. MID AND HIGH CLOUDS WILL SPREAD ACROSS SOUTHEAST WI BEGINNING WED EVENING AS LOW PRESSURE APPROACHES FROM MANITOBA. WIDESPREAD SNOW IS EXPECTED OVER A LONG PERIOD OF TIME FROM LATE WEDNESDAY NIGHT THROUGH FRIDAY MORNING. SEE THE TOP NEWS OF THE DAY STORY ON OUR WEBSITE FOR A BREAK-DOWN IN SNOW AMOUNTS AND TIMING. MARINE... LOW PRESSURE WILL MOVE INTO THE GREAT LAKES REGION ON WEDNESDAY... THEN INTENSIFY ON THURSDAY RESULTING IN INCREASING NORTHWEST WINDS. WINDS AND WAVES ARE EXPECTED TO REACH SMALL CRAFT ADVISORY LEVELS THURSDAY AFTERNOON THROUGH FRIDAY. THERE MAY BE A FEW GALE FORCE GUSTS WITH THIS SYSTEM. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...MBK ______________________________________________________________________ KMKX - Reference: ['warm front. recent modis imagery shows the lake sfc temperature'] 685 FXUS63 KMKX 300335 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 935 PM CST SUN JAN 29 2012 .UPDATE...LIGHT SNOW FROM BURST OF WARM AIR ADVECTION AHEAD OF SURFACE WARM FRONT BEGINNING TO SPREAD INTO PARTS OF WESTERN MN. STRENGTH OF FORCING OVERWHELMING DRY LOW LEVELS IN THE NORTHERN PLAINS. STRONGEST WARM AIR ADVECTION SWEEPS ACROSS SOUTHERN WISCONSIN BETWEEN 09Z AND 15Z. IMPRESSIVE LAYER Q-VECTOR CONVERGENCE AND FN VECTOR RESPONSE TO FWF IN THE LOW LEVELS SWEEPS THROUGH SRN WI WITH THE WAA. AT THIS TIME...THINKING STRONGEST FORCING ACROSS NRN/CENTRAL WI WL BE ABLE TO SATURATE LOW LEVELS ENOUGH TO RESULT IN LIGHT SNOWFALL...UP TO AN INCH. CENTRAL AREAS FROM MADISON TO MILWAUKEE WILL PROBABLY SEE A PERIOD OF -SN BUT SATURATION IN THE LOW LEVELS REMAINS MUCH LESS...HENCE WL CONTINUE CHANCE WORDING FOR THESE AREAS. LIGHT SNOW THREAT PUSHES RAPIDLY NORTHEAST WITH WAA BY 18Z. STILL A POTENTIAL FOR A BRIEF PD OF -ZL AS THE WARM AIR CONTINUES TO SURGE INTO SRN WI MONDAY MRNG. && .AVIATION/06Z TAFS/...THICKENING CLOUDS WL OCCUR THE REST OF THE NIGHT WITH CIGS LOWERING TO AROUND 5-6K FT. BRIEF BURST OF STRONG WARM AIR ADVECTION WILL SWEEP THROUGH SOUTHERN WISCONSIN LATE TNGT AND MONDAY MRNG. POSSIBLE A BRIEF PERIOD OF -SN OR -ZL COULD AFFECT TAF SITES WITH CIGS BRIEFLY LOWERING TO MVFR FOR AN HOUR OR TWO BETWEEN 12Z AND 17Z MONDAY. LOW LEVELS REMAIN DRY SO NOT EXPECTING ANY PERSISTENT LOW CLOUDS OR FOG. && .MARINE...A BRIEF PERIOD OF GUSTY WINDS IS EXPECTED MONDAY MORNING AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF AN APPROACHING WARM FRONT. RECENT MODIS IMAGERY SHOWS THE LAKE SFC TEMPERATURE AROUND 2C. FORECAST SOUNDINGS OVER THE NEARSHORE WATERS MONDAY MORNING SHOW A STRONG INVERSION AROUND 2K FEET...HOWEVER WINDS BELOW THE INVERSION STRENGTH TO AROUND 25 KTS FROM THE SOUTHEAST. DUE TO BRIEF NATURE OF STRONGER WINDS...WL HOLD OFF ON ISSUING SMALL CRAFT ADVY AT THIS TIME...AND LET MIDNIGHT SHIFT TAKE ONE MORE LOOK AT TIMING. THE WINDS WILL SETTLE DOWN AS THE WARM FRONT MOVES ACROSS WESTERN LAKE MI LATE MONDAY MORNING AND EARLY AFTERNOON. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...MBK ______________________________________________________________________ KMKX - Reference: ['rates. new modis imagery shows lake mi sea sfc temp around 3.5c. '] 319 FXUS63 KMKX 082124 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 320 PM CST WED FEB 8 2012 .VERY SHORT TERM...TONIGHT AND THURSDAY. HIGH PRESSURE OVER THE MIDWEST WILL DRIFT SOUTHEAST TONIGHT AND THURSDAY. A SHORTWAVE DROPPING SOUTHEAST FROM THE DAKOTAS WILL STAY WELL TO THE SOUTH OF WISCONSIN OVERNIGHT AND WILL HAVE NO IMPACT ON OUR WEATHER OR CLOUDS. DRY AIR IN THE REGION WILL ALLOW FOR CLEAR SKIES TONIGHT AND SUNNY SKIES ON THURSDAY. HIGH CLOUDS MAY SEEP INTO SOUTHERN WI LATER THURSDAY AFTERNOON AS A COLD FRONT APPROACHES FROM THE NORTH. WINDS WILL GENERALLY BY OUT OF THE WEST TONIGHT AND SOUTHWEST ON THURSDAY. AN INCREASING PRESSURE GRADIENT BETWEEN A SFC LOW OVER SOUTHERN ONTARIO AND HIGH PRESSURE OVER KENTUCKY WILL BRING INCREASING WINDS TO SOUTHERN WI BY LATE THU MORNING. A FEW GUSTS TO 20 KNOTS/23 MPH WILL BE POSSIBLE BY THU AFTERNOON. DESPITE WEAK WARM AIR ADVECTION WE COULD STILL RADIATE OUT FAIRLY WELL TONIGHT. TRENDED TOWARD COLDER SIDE OF GUIDANCE. SUNSHINE AND CONTINUED WEAK WARM AIR ADVECTION WILL BRING MAX TEMPS A LITTLE WARMER THAN TODAY...IN THE MID 30S TO AROUND 37 NEAR THE LAKESHORE. THOUGH TEMPS MAY FEEL A LITTLE COOLER DUE TO THE WIND. .SHORT TERM...THURSDAY NIGHT THROUGH SATURDAY. SHORT TERM GUIDANCE IN GOOD AGREEMENT ON CARRYING VIGOROUS CDFNT NOW ADVANCING INTO SRN CANADA...FM 06Z-13Z FRIDAY. IN THE WAKE OF THE FRONT...LINGERING LOW TO MID LEVEL MOISTURE WILL INTERACT WITH PASSING MID-LEVEL SHORT WAVE TO PRODUCE A PERIOD OF SCT -SHSN OVER SRN WI INTO THE EARLY AFTN BFR DIMINISHING. SYNOPTIC SCALE FORCING WL BE TEMPERED SOMEWHAT BY STRONG DOWNWARD OMEGA ASSOCD WITH COLD AIR ADVECTION. HENCE WL KEEP SNOW AMOUNTS LIGHT...LESS THAN ONE HALF INCH MOST LOCATIONS. HOWEVER...LATEST RUNS OF THE WRF-NAM ALONG WITH THE 12Z ECMWF SHOW A PERIOD OF LAKE EFFECT ENHANCED FORCING OVER THE NEARSHORE AREAS FRIDAY MRNG...DIMINISHING IN THE AFTN. LAKE SNOW PARAMETER REACHS 1-2 UNITS ON FRIDAY INDICATING MDT POTENTIAL FOR HIGH SNOWFALL RATES. NEW MODIS IMAGERY SHOWS LAKE MI SEA SFC TEMP AROUND 3.5C. THIS RESULTS IN THE DELTA-T INCREASING TO AROUND 17 DEGREES ON FRIDAY AS 85H TEMPS PLUMMET TO BTWN 10 AND 18C BLO ZERO. 850-700H RH INITIALLY AROUND 90 PERCENT DECREASES TO 50 PERCENT DURING THE AFTN WITH THE INVERSION HEIGHT ABV 6K FT. LAKE INDUCED CAPE OVER 200 J/KG. HWVR SEVERAL NEGATIVES FOR PRODUCING AN ENHANCED SNOW BAND INCLUDED BEST FETCH REMAINING 010-020 DEGREES AND FLUCTUATING WIND DIRECTION IN THE 1000-850H LEVEL. WINDS TURN TO 010-020 DEGREES BY 15Z FRIDAY...BUT THEN BACK TO 360 DEGREES BY THE EARLY AFTN. HENCE THIS FETCH WOULD FAVOR THE AREA FROM MILWAUKEE COUNTY SOUTH TO THE IL BORDER FOR A PERIOD OF -SHSN ENHANCED BY SYNOPTIC SCALE FORCING FROM SHORT WAVE. GFS MEANWHILE NOT AS AGGRESSIVE WITH LAKE EFFECT THREAT WITH WINDS REMAINING MORE NLY FRI AND FRI NGT. FEEL CONFIDENT THAT BTWN LAKE EFFECT AND SYNOPTIC SCALE FORCING...SCATTERED SNOW SHOWERS CAN BE EXPCD FOR A TIME ON FRIDAY. FOR NOW WL KEEP SNOW AMOUNTS UP TO AN INCH BY THE LAKE DUE TO UNCERTAINTY. WL KEEP A SMALL CHANCE CLOSE TO THE LAKE INTO FRI NGT DUE TO THE LINGERING N WINDS...BUT REMOVE THE THREAT ON SAT AS WINDS BACK TO THE WEST. COLD AIR REMAINS ANCHORED OVER SRN WI ON SATURDAY...BUT LACK OF SNOW COVER AND SUNSHINE SHOULD ALLOW TEMPS TO REBOUND 10 TO 15 DEGREES ON SAT. .LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. APPEARS A TRANSITION TOWARD MORE UNSETTLED CONDITIONS WL TAKE PLACE LATER IN THE EXTENDED PERIOD. AT FIRST...QUIET AND COLD CONDITIONS WILL LINGER OVER SRN WI THROUGH THE LATER HALF OF THE WEEKEND AS A LARGE AREA OF HIGH PRESSURE PASSES ACROSS THE CENTRAL CONUS. TEMPS WL REMAIN CLOSE TO SEASONAL NORMAL ON SUNDAY. LARGE RIDGE WL CONTINUE TO THE EAST SUNDAY NIGHT INTO MONDAY AS PIECES OF SHORT WAVE ENERGY EJECTED FROM NRN PACIFIC LONG WAVE TROUGH ADVANCE ACROSS WRN CONUS. EXTENDED GUIDANCE SHOWING REASONABLE AGREEMENT AND CONTINUITY IN BRINGING MID-LEVEL SHORT WAVE ACROSS UPPER MIDWEST AND WRN GTLAKES MON NGT. STRENGTHENING LOW LEVEL WINDS AHEAD OF THIS FEATURE ARE EXPECTED TO INCREASE PWAT VALUES TO OVER 0.5 INCH. FOR NOW WL BUMP UP POPS TO BETTER CHANCE VALUES FOR -SN WITH POTENTIAL FOR AN INCH OR TWO OF NEW SNOW. ABOVE SHORT WAVE WL CONTINUE TO THE EAST OF WI BY TUESDAY...LIKELY RESULTING IN A BREAK IN THE PRECIPITATION. WHILE MEDIUM RANGE ENSEMBLES SHOW SOME AGREEMENT WITH MONDAY NIGHT SHORT WAVE...THEY RAPIDLY DIVERGE BY MID-WEEK AS EXTENDED GUIDANCE IS HAVING DIFFICULTY WITH TRACK AND TIMING OF NEXT STRONGER SYNOPTIC SYSTEM TO ADVANCE INTO THE SRN PLAINS TUE AND WED. MILDER AIR WL SETTLE OVER SRN WI BY MID-WEEK...SO THERE WOULD BE A THREAT OF MIXED PRECIP OVER PARTS OF THE AREA BY THE TIME PRECIP CHANCES RETURN ON WED. && .AVIATION /00Z TAFS/... VFR CONDITIONS EXPECTED ACROSS THE FORECAST AREA. HIGH PRESSURE OVER THE MIDWEST WILL DRIFT SOUTHEAST TONIGHT AND THURSDAY. WEST TO SOUTHWEST WINDS WILL INCREASE ON THU WITH AN INCREASING PRESSURE GRADIENT BETWEEN LOW PRESSURE OVER ONTARIO AND HIGH PRESSURE OVER KENTUCKY. CLOUDS WILL INCREASE THURSDAY LATE AFTERNOON INTO THURSDAY NIGHT AS AN ARCTIC FRONT DROPS SOUTH ACROSS WI. LIGHT SNOW SHOWERS WILL BE POSSIBLE WITH THE FRONT LATE THU NIGHT INTO FRIDAY. && .MARINE... INCREASING SOUTHWEST WINDS ON THURSDAY AND THURSDAY NIGHT WILL APPROACH SMALL CRAFT ADVISORY CONDITIONS. SMALL CRAFT ADVISORIES ARE EXPECTED FRIDAY INTO FRIDAY NIGHT BEHIND A STRONG COLD FRONT. THE GUSTY NORTH WINDS WOULD CREATE HIGH WAVES FRIDAY...LASTING INTO SATURDAY. && .CONFIDENCE... TONIGHT AND THURSDAY...HIGH. THURSDAY NIGHT AND FRIDAY...MEDIUM. FRIDAY NIGHT THROUGH SUNDAY NIGHT...MEDIUM TO HIGH. MONDAY THROUGH TUESDAY...MEDIUM. WEDNESDAY...LOW. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ SHORT TERM/LONG TERM...MBK VERY SHORT TERM/AVIATION/MARINE...MRC ______________________________________________________________________ KMKX - Reference: ['waters through early this morning. latest modis imagery shows '] 536 FXUS63 KMKX 180907 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 307 AM CST SAT FEB 18 2012 .TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM TO HIGH FLURRIES ASSOCD WITH INITIAL SURGE OF COLD AIR ADVECTION AND LOW LEVEL CONVERGENCE ALONG SFC FRONT SHOULD END EARLY THIS MORNING AS WEAK FORCING SLIDES OFF TO THE EAST. HEAVIER SNOW SHOWERS ASSOCIATED WITH UPPER LEVEL WAVE HAVE PUSHED TO THE EAST OF KSBM CWA AS WELL. APPEARS NAM OVERDOING LOW LEVEL MOISTURE ONCE AGAIN AS MOSTLY MID-LEVEL CLOUDS UPSTREAM. WITH STRONG SUBSIDENCE ASSOCIATED WITH APPROACHING RIDGING AND SHORT WAVE PUSHING OFF TO THE EAST...WL CONTINUE TREND OF DECREASING CLOUDS DURING THE MORNING WITH FEW-SCT CU THIS AFTN MOST AREAS DUE TO SUBSIDENCE. SUNSHINE AND A LACK OF SNOW COVER SHOULD HELP TEMPS REBOUND INTO THE MID 30S MOST AREAS DESPITE NORTHWEST LOW LEVEL WINDS AND THERMAL TROUGH LINGERING OVER THE EAST. LIGHT BOUNDARY LAYER WINDS AND CLEAR SKIES WILL ALLOW TEMPS TO FALL INTO THE MID TEENS TO LOWER 20S MOST AREAS. AS THE LOW LEVEL RIDGE AXIS SETS UP TO THE NORTH TONIGHT...LIGHT ONSHORE FLOW MAY HAVE JUST ENOUGH LOW LEVEL MOISTURE TO CAUSE SOME LAKE CLOUDS TO PUSH ASHORE FROM KMKE SOUTH TO KENW AFT MIDNIGHT TNGT. NOT ENOUGH MOISTURE AND CONVERGENCE TO EXPC FLURRIES AT THIS POINT. .SUNDAY...FORECAST CONFIDENCE...HIGH WITH NORTHEAST LOW LEVEL FLOW EXPECTED SUNDAY...MAY SEE LAKE CLOUDS IN THE SOUTHEAST...PARTICULARLY IN THE MORNING. OTHERWISE...HIGH PRESSURE WILL BRING QUIET WEATHER TO SOUTHERN WISCONSIN. HIGH TEMPS SHOULD REMAIN A BIT ABOVE NORMAL...WITH MID 30S ANTICIPATED. .MONDAY AND TUESDAY...FORECAST CONFIDENCE...LOW TO MEDIUM HIGH PRESSURE TO SLIDE EAST MONDAY AHEAD OF APPROACHING LOW PRESSURE...WITH CLOUDS INCREASING FROM THE WEST. INCREASED POPS JUST A BIT MORE FOR MONDAY NIGHT AND TUESDAY...WITH ENOUGH OVERLAP IN MODEL TIMING OF THE LOW. OVERALL THOUGH...MODELS HAVE NOT COME INTO BETTER AGREEMENT WITH THIS SYSTEM...WITH VARYING TIMING AND TRACKS OF THE LOW. THUS NOT ENOUGH CONFIDENCE TO INCREASE POPS THAT MUCH FOR NOW. ENOUGH OF A WARM LAYER IN THE NAM SOUNDINGS AND SOMEWHAT IN GFS SOUNDINGS TO GO WITH A SLIGHT CHANCE FOR SLEET TO GO WITH SNOW FOR MONDAY NIGHT...FOLLOWED BY RAIN/SNOW CHANCES TUESDAY. WITH SUNSHINE EXPECTED FOR AT LEAST THE MORNING MONDAY...AND SOUTHERLY WINDS AHEAD OF THE LOW THROUGH MONDAY NIGHT OR TUESDAY MORNING...WILL LIKELY SEE EVEN MILDER TEMPS FOR THE BEGINNING OF THE WORK WEEK. SHOULD SEE HIGHS IN THE UPPER 30S TO AROUND 40. .WEDNESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...LOW TO MEDIUM A PAIR OF SYSTEMS ARE PROGGED TO MOVE THROUGH THE GREAT LAKES WEDNESDAY THROUGH FRIDAY. SIZABLE DIFFERENCES BETWEEN THE GFS AND ECMWF TO JUST GO WITH A SLIGHT CHANCE OF RAIN/SNOW WED/THU AND SNOW FRI. ABOVE NORMAL TEMPS EXPECTED TO CONTINUE THROUGH THE LATTER HALF OF THE WORK WEEK. && .AVIATION/12Z TAFS/...SPOTTY MVFR CIGS ASSOCD WITH FLURRIES AND LOW LEVEL COLD AIR ADVECTION BEHIND CDFNT EARLY THIS MORNING SHOULD RAPIDLY THIN AND PUSH TO THE EAST LEAVING VFR FOR MOST OF THE TAF PD. SOME CU MAY DEVELOP LATER THIS MRNG AND AFTN...BUT COUNTING ON STRONG SUBSIDENCE TO KEEP CU MVFR AND SCT-BKN. HENCE WL BE MORE OPTIMISTIC WRT SKY CONDITIONS WITH 12Z ISSUANCE. MVFR LAKE CLOUDS MAY AFFECT ERN TAF SITES AFT MID TNGT. && .MARINE...COLD FRONT WILL EXIT SOUTHERN LAKE MICHIGAN EARLY THIS MRNG. WEST WINDS 5 TO 10 KTS AHEAD OF THE FRONT TURNED TO THE NORTH UPON FROPA AND INCREASED TO 10 TO 20KTS. LOW LEVEL COLD AIR ADVECTION BEHIND FRONT WILL RESULT IN GUSTY WINDS OVER THE NEARSHORE WATERS THROUGH EARLY THIS MORNING. LATEST MODIS IMAGERY SHOWS MID-LAKE TEMPS AROUND 4C SO ESTIMATE NEARSHORE LAKE TEMPS AROUND 1-2C. ENOUGH STEEPNESS TO THE LOW LEVEL LAPSE RATES TO PRODUCE A FEW GUSTS TO 22-25 KNOTS THROUGH 15Z...BUT NOT EXPCD TO BE FREQUENT ENOUGH TO WARRANT SMALL CRAFT ADVY. NORTH WINDS WL BACK TO THE NORTHWEST TODAY AND DIMINISH AS HIGH PRESSURE RIDGE SETTLES INTO THE WRN GTLAKES FROM THE NRN PLAINS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...MBK SUNDAY THROUGH FRIDAY...DDV ______________________________________________________________________ KMKX - Reference: ['this evening...and continuing thru tonight. modis imagery shows '] 262 FXUS63 KMKX 200941 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 341 AM CST MON FEB 20 2012 .TODAY...FORECAST CONFIDENCE...HIGH A BIT MORE WIND IS EXPECTED TODAY AS THE PRESSURE GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH PRESSURE SYSTEM OVER LOWER MI AND THE LOW PRESSURE SYSTEM THAT WILL BE MOVING FROM THE HIGH PLAINS OF COLORADO THRU KS BY 00Z/TUE. QUITE A BIT OF CIRRUS AHEAD OF THE LOW SPREADING NORTH AND EAST IN THE INCREASING WARM AIR ADVECTION ALOFT. FORTUNATELY THE MID-LAYERS OF THE ATMOSPHERE WL REMAIN DRY ENOUGH TO ALLOW AT LEAST PARTIAL SUNSHINE FOR MUCH OF THE DAY...WHICH WILL ALLOW TEMPS TO ONCE AGAIN WARM TO ABV NORMAL BY MID-AFTN. SOUTHEAST WINDS AT THE LAKE WL KEEP LAKESHORE LOCATIONS A FEW DEGREES COOLER...AS LAKE SFC TEMPS MOSTLY 36 TO 39 DEGREES. .TONIGHT...FORECAST CONFIDENCE...MEDIUM SHORT TERM GUIDANCE IN GOOD AGREEMENT ON CARRYING NEGATIVELY-TILTED MID LEVEL TROUGH FROM THE CENTRAL PLAINS INTO FAR WRN WI AND ERN IA BY 12Z/TUE. PRECIPITABLE WATER VALUES INCREASE RAPIDLY AFTER 06Z TO AROUND 0.5 INCH DUE TO STRENGTHENING LOW LEVEL WINDS TO 40-50KTS AHEAD OF TROUGH. RAPID LOWERING OF CONDENSATION PRESSURE DEFICITS TO LESS THAN 10MB WITH 15 TO 25KT UPGLIDE ON 290 THETA SFC. DESPITE LAYER Q-VECTOR CONVERGENCE NOT BEING ALL THAT IMPRESSIVE...ALL GUIDANCE IN AGREEMENT ON CARRYING PERIOD OF ENHANCED SYNOPTIC SCALE FORCING ASSOCD WITH LEFT EXIT REGION OF 3H JET ACROSS SRN WI BTWN 06Z AND 15Z/TUE. THERMODYNAMIC COOLING TAKES PLACE AS AIR MASS MOISTENS WHICH WILL RESULT IN MOSTLY LIGHT SNOW ACROSS SRN WI. ALL TECHNIQUES INCLUDING ROEBBER AND COBB FAVOR AROUND A 12-13 TO 1 SLR. HEAVIEST QPF OVER 0.10 LIKELY TO BE IN THE SOUTHWEST SO SNOW AMOUNTS COULD REACH 2 INCHES IN THIS AREA BY 12Z. WL BUMP UP POPS MOST LOCATIONS. NOT SEEING MUCH FN VECTOR RESPONSE TO FWF SO WL KEEP QPF/SNOW AMOUNTS CLOSER TO GUIDANCE VALUES. .TUESDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH CURRENT MODELS IN PRETTY GOOD AGREEMENT WITH WIDESPREAD SNOW ACROSS SRN WI AT DAYBREAK TUESDAY. WENT WITH HIGH EARLY MORNING POPS...BUT TAPERED THEM OFF TO MAINLY CHANCE FOR THE LATTER HALF OF THE MORNING AS DRIER AIR FILTERS INTO THE MID LEVELS. MODELS SOUNDINGS SHOWING ENOUGH LIFT AND LOWER LEVEL SATURATION TO KEEP SOME LOW POPS GOING IN THE AFTERNOON...MAINLY EAST OF MADISON. BETWEEN THE DRIER AIR POSSIBLY CUTTING OFF ICE CRYSTAL DEVELOPMENT...WAA ALOFT...AND A MILD SW FLOW AT THE SFC...WENT WITH RAIN/SNOW MIX FOR THE AFTERNOON. THE BULK OF THE PRECIPITATION WILL BE SNOW THOUGH...OCCURRING DURING THE FIRST PART OF THE MORNING. THOUGH CLOUDS WILL LINGER THROUGH THE DAY...ABOVE MENTIONED TEMPERATURE SETUP SHOULD ALLOW HIGH TEMPS TO SNEAK BACK TO AROUND 40. NOT SURE HOW MUCH OF AN EFFECT NEW SNOW WILL HAVE ON TEMPS. WITH HIGHS TODAY EXPECTED TO REACH THE LOW 40S...LOWS TONIGHT IN THE LOW 30S...WILL NOT TAKE MUCH FOR THE SNOW TO MELT AFTER IT STOPS SNOWING. LIMITING FACTOR MAY BE LACK OF SUNSHINE...SO DID NOT GO WITH WARMEST GUIDANCE. .WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...LOW TO MEDIUM STILL A BIT OF A MESS MID WEEK WITH MODEL AGREEMENT AND GENERAL RUN TO RUN CONSISTENCY IN INDIVIDUAL MODELS. OVERALL PICTURE IS A PAIR OF SHORTWAVES WEDNESDAY AND THURSDAY...THE SECOND ONE STRONGER THAN THE FIRST. BIG ISSUES WITH WHERE MODELS DEVELOP THE SFC FEATURES AND ASSOCIATED PRECIP. HARD TO PIN DOWN A LOT OF THE DETAILS...BUT DOES LOOK LIKE CONTINUED MILD PATTERN...SO WENT WITH CHANCE OF RAIN/SNOW FOR NOW. .FRIDAY AND SATURDAY...FORECAST CONFIDENCE...MEDIUM MODELS IN DECENT AGREEMENT WITH A RETURN TO NEAR NORMAL TEMPERATURES FOR FRIDAY AND SATURDAY. WENT WITH CHANCE OF SNOW FRIDAY WITH UPPER TROUGH RIGHT OVERHEAD...THEN DRY SATURDAY. .SUNDAY...FORECAST CONFIDENCE...LOW ECMWF AND GFS DIVERGE FOR THE END OF THE WEEKEND. THE GFS BRINGS A SFC LOW THROUGH SUNDAY JUST SOUTH OF THE WI/IL BORDER...WHILE THE ECMWF HOLDS OFF ON THE LOW UNTIL MONDAY...PUSHING IT THROUGH NORTH OF THE FORECAST AREA. OBVIOUS SIGNIFICANT DIFFERENCES IN TEMPS AND PRECIP TYPES...SO JUST WENT WITH CHANCE OF RAIN/SNOW SUNDAY UNTIL THINGS BECOME MORE CLEAR. && .AVIATION/12Z TAFS/...VFR CONDITIONS WL CONTINUE INTO THIS EVENING BEFORE IFR/LIFR CIGS AND VSBYS OVERSPREAD SRN WI AFT 06Z TNGT. WINDS TNGT WL EXCEED 40KTS AT 2K FEET SO WL INTRODUCE LLWS REMARK. && .MARINE...TIGHTENING PRESSURE GRADIENT WILL DEVELOP OVER LAKE MICHIGAN TODAY AS HIGH PRESSURE OVER LWR MI PUSHES FARTHER TO THE EAST WHILE LOW PRESSURE STRENGTHENS OVER THE CENTRAL AND NORTHERN PLAINS. STEEP LOW LEVEL LAPSE RATES OVER THE NEARSHORE WATERS WITH SOUTH TO SOUTHEAST SFC WNDS WL ALLOW GUSTS TO 25 KTS TO DEVELOP BY THIS EVENING...AND CONTINUING THRU TONIGHT. MODIS IMAGERY SHOWS LAKE SFC TEMP 2-4C FROM THE NEARSHORE WATERS TO MID-LAKE. WL ALLOW SMALL CRAFT TO EXPIRE TUE MRNG...BUT MAY NEED TO BE REISSUED TUE AFTN INTO TUE NIGHT AS PRESSURE GRADIENT RETIGHTENS AND WINDS INCREASE BEHIND SURFACE LOW PRESSURE TROUGH. THIS TROUGH WILL BE MOVING ACROSS LAKE MI TUE MRNG RESULTING IN THE TEMPORARY LULL IN WIND SPEEDS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 9 AM CST TUESDAY FOR LMZ643>646. && $$ TODAY/TONIGHT AND AVIATION/MARINE...MBK TUESDAY THROUGH SUNDAY...DDV ______________________________________________________________________ KMKX - Reference: ['considerably cooler. latest modis images show lake mi lake sfc ', 'temps were between 37 and 40 degrees fahrenheit per modis imagery '] 852 FXUS63 KMKX 142041 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 340 PM CST WED MAR 14 2012 .VERY SHORT TERM...TONIGHT AND THURSDAY. CHALLENGING FORECAST WITH HIGH UNCERTAINTY IN A WEAK THUNDERSTORM CHANCE...FOG/STRATUS DEVELOPMENT...AND THURSDAY MAX TEMPERATURES. WARM AIR AND LOW LEVEL MOISTURE STREAMED INTO SOUTHERN WI THIS AFTERNOON AHEAD OF A LOW PRESSURE TROUGH CURRENTLY SITUATED FROM WESTERN LAKE SUPERIOR INTO WESTERN IOWA. THE STRATUS IN NORTHEAST IOWA AND FAR WESTERN WI STAYED OUT OF THE FORECAST AREA IN THE AFTERNOON...PROVING THAT WE WERE UNDER A WELL-MIXED ENVIRONMENT. CUMULUS CLOUDS DEVELOPED ACROSS SOUTHERN WI LATE THIS AFTERNOON AT THE TOP OF THE MIXED LAYER...AROUND 3500 TO 4000 FEET AGL. THE CU ARE VERY SHALLOW DUE TO THE CAP. MAINTAINED THE SLIGHT CHANCE FOR THUNDERSTORMS FROM MID EVENING THROUGH LATE TONIGHT BUT VERY LOW CONFIDENCE IN THIS OCCURRING. THE HRRR AND SPC 4 KM WRF NMM SHOW A FEW SHOWERS BREAKING OUT. GIVEN THE INSTABILITY WITH CAPE OVER 1000 J/KG...KEPT WITH THE TSTORM THINKING. HOWEVER THE CHANCE IS VERY LOW. THERE IS VERY LITTLE UPPER LEVEL FORCING AND NO UPPER LEVEL MOISTURE TO WORK WITH. THE NEXT CHALLENGE IS THE POSSIBILITY FOR FOG AND STRATUS TO DEVELOP LATE TONIGHT/THU MORNING. VERY LOW CONFIDENCE IN THIS SCENARIO...BUT IT IS HARD TO IGNORE THE PERSISTENT MOS GUIDANCE SUGGESTING DENSE FOG. GIVEN DEWPOINT TEMPS IN THE MID/UPPER 50S THIS AFTERNOON /CROSSOVER TEMPS/ AND FORECAST TEMPS TO COOL LATE TONIGHT AS THE TROUGH/WEAK PRESSURE GRADIENT COMES OVERHEAD...THERE IS POTENTIAL FOR FOG TO DEVELOP AND POSSIBLY BECOME DENSE. IT IS DIFFICULT TO PICTURE THIS SCENARIO SINCE THE ATMOSPHERE HAS BEEN SO DRY AND TEMPS ARE SO WARM TODAY THAT THEY MAY NOT DROP BELOW THE CROSSOVER TEMPS...ESPECIALLY IN THE SOUTHERN FORECAST AREA. THEREFORE...DID NOT ISSUE A DENSE FOG ADVISORY...BUT MENTIONED AREAS OF FOG WITH PATCHY DENSE FOG IN FORECAST LATE TONIGHT INTO THUR MORNING. A BACK DOOR COLD FRONT WILL ZIP DOWN LAKE MICHIGAN MID THU MORNING. THE CANADIAN MODEL IS QUICKER WITH THE WIND SHIFTING TO THE NORTHEAST THAN THE NAM. WINDS SHOULD INCREASE ALONG THE LAKESHORE WITH THE FRONT...THEN REMAIN SOMEWHAT ELEVATED AROUND 10 KNOTS THROUGH THE MID AFTERNOON WITH THE STRONGER PRESSURE GRADIENT. THIS COLD FRONT SCENARIO PAINTS A DREARY PICTURE FOR MILWAUKEE ON THURSDAY. CAN/T RULE OUT DRIZZLE WITH LOW CLOUDS...GUSTY NORTHEAST WINDS FOR A TIME AND COOL TEMPERATURES FROM THE LAKE. LAKE MICHIGAN TEMPS WERE BETWEEN 37 AND 40 DEGREES FAHRENHEIT PER MODIS IMAGERY YESTERDAY EVENING. UNCERTAIN HOW FAR INTO SOUTH CENTRAL WI THE FRONT WILL MAKE IT ON THU. THE CANADIAN BRINGS IT ALL THE WAY TO MSN AND THE NAM DOES NOT. TRIED TO BLEND THE TWO MODEL SOLUTIONS FOR TEMPS AND WINDS. .SHORT TERM...THURSDAY NIGHT THROUGH SATURDAY. WL CONTINUE TO LEAN MORE ON HIGHER RESOLUTION NAM SOLUTION FOR THIS PERIOD...WITH SURFACE FRONTAL BOUNDARY NUDGED FARTHER SOUTH DEEPER INTO NRN IL AT START OF PERIOD. WITH MOIST LIGHT LOW LEVEL NORTHEAST FLOW BELOW INVERSION EXPCD TO CONTINUE...WL CARRY FOG MENTION THRU THURSDAY NIGHT...AND CONFINE TO THE EAST...CLOSER TO COOL LAKE MI ON FRI. MAY BE UNDERDOING AMOUNT OF CLOUD COVER NORTH OF FRONTAL BOUNDARY DUE TO MOIST LOW LEVEL NORTHEAST FLOW BUT CONCERNED ABOUT DRY AIR ENTRAINMENT FROM THE NORTH THU NGT INTO FRI. DEWPTS FALL INTO THE TEENS AND 20S BEHIND THE FRONT IN THE NRN PLAINS. FOG SHOULD BEGIN TO BREAK UP AS BOUNDARY LAYER GETS BETTER MIXED FRIDAY MRNG. FRONTAL BOUNDARY BEGINS TO SHIFT NORTHWARD LATER FRIDAY AND FRIDAY NIGHT IN RESPONSE TO INCREASING LOW LEVEL SW FLOW. CAPPING DOES DECREASE FRI AFTN BUT LACK OF ANY TRIGGER PRECLUDES ADDING ANY POPS FOR NOW. BETTER CHANCE APPEARS FRI NIGHT AS MID LEVEL WARM AIR ADVECTION INCREASES ALONG WITH ELEVATED MOISTURE. COINCIDENTALLY... WEAK MID LEVEL SHORT WAVE CAUGHT IN SOUTHWEST FLOW MOVES THRU SRN WI. WEAK LAYER Q-VECTOR CONVERGENCE BRUSHES SRN WI AS WELL...SO ENUF EVIDENCE TO WARRENT ADDING SCHC POPS FRI NGT...CARRYING INTO SAT. BULK OF SAT SHOULD BE DRY HOWEVER AS WK FORCING WL HAVE SHIFTED TO THE NORTHEAST EARLY. SAT EXPCD TO BE WARMER MOST LOCATIONS WITH BETTER SLY SFC WINDS. .LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. NO SIGNIFICANT CHANGES PLANNED FOR THIS PERIOD. APPEARS AMPLIFYING UPSTREAM LONG-WAVE TROFFING WL CONTINUE TO BRING WARM SOUTHERLY FLOW AND RESULTING UNSEASONABLY WARM TEMPERATURES TO MOST OF SRN WI FOR THE BULK OF THIS PERIOD. RIGHT THROUGH 00Z/22...GFS 500H 5 DAY MEAN HEIGHTS REMAIN 100 TO 200 METERS ABV NORMAL ACRS SRN WI. HOWEVER...GFS DIVERGING FROM OTHER LONG RANGE GUIDANCE LATER IN THE EXTENDED PERIOD. ECMWF HAS BEEN TRENDING TOWARD MORE PROGRESSIVE PATTERN MID-WEEK WITH UPSTREAM PIECE OF ENERGY DIGGING INTO BACK SIDE OF LONG WAVE TROUGH ON TUESDAY. THIS RESULTS IN LONG WAVE TROUGH EDGING SLOWLY EWD THRU CENTRAL CONUS...WITH SFC FRONT MOVING THRU AREA LATE TUE NGT AND WED. MEANWHILE...LAST SEVERAL DETERMINISTIC RUNS OF THE GFS HAVE TRENDED TOWARD PERSISTENT BLOCKING HIGH OVER ERN CONUS CONTINUING THROUGH MID-WEEK...PREVENTING EWD PROGRESSION OF LONG WAVE TROUGH. AS A RESULT...GFS TRENDING TOWARD CUT-OFF UPPER LOW DEVELOPING OVER THE SRN PLAINS. THIS UPPER LOW WOULD EVENTUALLY GET NUDGED NORTHEAST INTO THE UPPER MIDWEST LATER IN THE WEEK BY UPSTREAM KICKER PUSHING TOWARD WEST COAST WED NGT AND THU. GFS ENSEMBLE MEMBERS FAVORING CUTOFF LOW...BUT SEVERAL MEMBERS LEAN TOWARD MORE PROGRESSIVE SOLUTION. HPC LEANING TOWARD ECMWF SOLUTION...BUT SLOWER EWD PROGRESSION...WHICH WOULD BE REASONABLE CONSIDERING BLOCKING RIDGE TO THE EAST. FOR NOW...CONFIDENCE WL BE LOWEST IN THE LATE PERIODS OF THE EXTENDED. TEMPERATURES EARLY NEXT WEEK WILL BE WILL BE FLIRTING WITH RECORD HIGHS INLAND...WHILE LAKE MICHIGAN KEEPS LAKESHORE TEMPERATURES CONSIDERABLY COOLER. LATEST MODIS IMAGES SHOW LAKE MI LAKE SFC TEMPERATURE REMAINING THE UPPER 30S TO LOW 40S. FOR MUCH OF THE EXTENDED PERIOD...UPPER LEVEL HEIGHT AND LOW LEVEL TEMPERATURE ANOMOLIES BETWEEN 3 AND 4 STANDARD DEVIATIONS. IN THE EARLIER PERIODS OF THE EXTENDED...WL CONTINUE LOW POPS FOR THUNDER SAT NGT INTO SUN AS PIECE OF MID-LEVEL ENERGY MOVES NORTHEAST ACROSS THE REGION. WARM MID-LEVEL AIR OVERSPREADS SRN WI AFTER THIS DISTURBANCE. CAPPING INVERSION PREVENTS ANY SIGNIFICANT PRPN THREAT EARLY NEXT WEEK...WITH LIMITED MOISTURE. && .AVIATION /00Z TAFS/... ALTHOUGH A SLIGHT CHANCE OF A THUNDERSTORM EXISTS THIS EVENING...DUE TO THE LACK OF FORCING WILL KEEP THE TAF FORECASTS DRY. A WEAK COLD FRONT WILL SAG SOUTH LATE TONIGHT...AND WITH THE INCREASED MOISTURE SOME FOG POTENTIAL WILL INCREASE ALONG WITH THE POSSIBILITY OF LIFR FOG OR IFR CEILINGS. VERY LOW CONFIDENCE IN FOG POTENTIAL...BUT IT SEEMS LIKE A GOOD ENOUGH CHANCE TO PUT INTO TAFS. WILL HOLD OFF MENTIONING DENSE FOG IN A TEMPO GROUP UNTIL BETTER CONFIDENCE DEVELOPS. A BACK DOOR COLD FRONT WILL ZIP DOWN LAKE MICHIGAN MID THU MORNING. WINDS WILL SHIFT TO THE NORTHEAST AND INCREASE ALONG THE LAKESHORE WITH THE FRONT...THEN REMAIN SOMEWHAT ELEVATED AROUND 10 KNOTS THROUGH THE MID AFTERNOON WITH THE STRONGER PRESSURE GRADIENT. THIS COLD FRONT SCENARIO PAINTS A DREARY PICTURE FOR MILWAUKEE ON THURSDAY. CAN/T RULE OUT DRIZZLE WITH LOW CLOUDS...GUSTY NORTHEAST WINDS FOR A TIME AND COOL TEMPERATURES FROM THE LAKE. && .MARINE... A WEAK COLD FRONT WILL SAG IN FROM THE NORTH LATE TONIGHT THEN A NORTHEAST FLOW AND LAKE COOLING EXPECTED ON THURSDAY. THERE IS POTENTIAL FOR DENSE FOG TO DEVELOP ACROSS LAKE MICHIGAN TONIGHT AS MOIST AIR WORKS ITS WAY INTO THE AREA. && .CONFIDENCE... TONIGHT AND THURSDAY...LOW. THURSDAY NIGHT AND FRIDAY...MEDIUM. FRIDAY NIGHT AND SATURDAY...LOW TO MEDIUM. SATURDAY NIGHT AND SUNDAY...LOW TO MEDIUM. MONDAY AND TUESDAY...MEDIUM. WEDNESDAY...LOW TO MEDIUM. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ SHORT TERM/LONG TERM...MBK VERY SHORT TERM/AVIATION/MARINE...MRC ______________________________________________________________________ KMKX - Reference: ['.marine...modis imagery from around 18z/20 shows lake sfc temp has'] 483 FXUS63 KMKX 210239 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 939 PM CDT TUE MAR 20 2012 .UPDATE...EXPECT UPSTREAM HIGH CLOUDS TO CONTINUE THINNING AS THEY PUSH EAST INTO BETTER RIDGING AND SUBSIDENCE. LOW LEVELS REMAIN DRY...AND WITH DECOUPLING OF BOUNDARY LAYER MIXING...TEMPERATURES WILL FALL INTO THE MID 50S TO MID 60S ACROSS SRN WI. WL LOWER TEMPS IN SOME NRN AND ERN LOCATIONS A FEW DEGREES. ALSO BUMPED UP WINDS ON TUESDAY AS DRY ADIABATIC LAPSE RATES THROUH 850H ARE EXPECTED TO ONCE AGAIN DEVELOP DURING THE LATE MRNG AND AFTN ALLOWING WIND GUSTS TO NEAR 30 KTS...DESPITE PATCHY HIGH CLOUDINESS. MORE RECORDS LIKELY TO TUMBLE ON WED. && .AVIATION/06Z TAFS/...EXPCD DRY VFR CONDITIONS TO CONTINUE FOR THIS TAF PD. LOW LEVEL MIXING WL RESULT IN GUSTY WINDS LATER WED MRNG AND AFTN ONCE AGAIN. && .MARINE...MODIS IMAGERY FROM AROUND 18Z/20 SHOWS LAKE SFC TEMP HAS WARMED INTO THE LOW TO MID 40S FROM THE NEAR SHORE WATERS OUT TO MID-LAKE. THE COMBINATION OF THESE WARMER TEMPERATURES AND DRIER AIR FLOWING FROM THE SOUTHEAST PREVENTING FOG FORMATION DESPITE SOUTHEAST WINDS. LOW LEVEL INVERSION EXPCD TO ONCE AGAIN PREVENT STRONGER WIND GUSTS FROM MIXING DOWN TO LAKE SURFACE ON WEDNESDAY. GUSTY WINDS WILL BE FOUND JUST INLAND FROM THE LAKE DUE TO MUCH STRONGER LOW LEVEL MIXING. && .FIRE WEATHER...STRONG AFTN BOUNDARY LAYER MIXING RESULTED IN DRY AIR MIXING TO THE SFC. DEWPTS TUMBLED INTO THE MIDDLE 40S DURING THE AFTN AT SOME LOCATIONS RESULTING IN RH VALUES BETWEEN 25 AND 30 PERCENT. ANOTHER DAY OF STRONG BOUNDARY LAYER MIXING IS ANTICIPATED ON WEDNESDAY. HOWEVER PERSISTENT SOUTH TO SOUTHEAST WINDS ARE EXPECTED TO USHER IN SLIGHTLY HIGHER DEWPTS FROM THE CENTRAL GTLAKES AND NRN OH VALLEY FOR WED. HENCE NOT EXPCNG AS LOW RH WED AFTN...BUT MAY DROP AS LOW AS 30 TO 35 PERCENT. ENERGY RELEASE COMPONENT FOR RAWS SITES EXPECTED TO REMAIN LESS THAN 40 ON WED SO CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TO BE APPROACHED...BUT NOT REACHED AT THIS TIME. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ MBK ______________________________________________________________________ KMKX - Reference: ['shore on sat. modis imagery from 18z friday shows lake sfc temps'] 200 FXUS63 KMKX 070235 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 935 PM CDT FRI APR 6 2012 .UPDATE...NEEDED TO LOWER OVERNIGHT TEMPS A COUPLE DEGREES IN SOME EASTERN SITES. WITH DRY DEWPOINTS LINGERING IN THE LOW TO MID 20S IN THOSE AREAS EXPECTED TO FALL INTO THE LOW TO MID 30S LATE TONIGHT...THINK FROST POTENTIAL IS SMALL AND WL BE CONFINED TO LOW AREAS. HENCE CHANGED AREAS OF FROST WORDING TO PATCHY. EXPECT ISOBARS TO BE ALIGNED 30 DEGREES OR LESS WITH THE LAKE MI SHORE ON SAT. MODIS IMAGERY FROM 18Z FRIDAY SHOWS LAKE SFC TEMPS REMAIN IN THE LOW TO MID 40S. HENCE EXPECTED THERMAL GRADIENT AND BAGGIER PRESSURE GRADIENT...AT LEAST IN THE MORNING...WL RESULT IN A MORE SOUTHEAST WIND COMPONENT FOR MUCH OF THE DAY ALONG THE LAKESHORE. HENCE WL NEED TO REEVALUATE WHETHER LAKESHORE MAX TEMPS FOR SAT NEED TO BE LOWERED SLIGHTLY WITH NEW FORECAST. OTRW NO CHANGES TO LATER PERIODS. && .AVIATION/06Z TAFS/...VFR CONDITIONS FOR MOST OF THE PERIOD. SCT -SHRA WILL AFFECT TAF SITES SAT AFTN...BUT CIGS WL REMAIN VFR. MAY BE A BRIEF PD OF SCT-BKN MVFR CLOUDS IMMEDIATELY BEHIND CDFNT LATE SUN AFTN AND/OR EVE. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ MBK ______________________________________________________________________ KMKX - Reference: ['next 24 hours. modis imagery from 17z/09 measured lake surface '] 377 FXUS63 KMKX 100831 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 331 AM CDT TUE APR 10 2012 .VERY SHORT TERM....TODAY AND TONIGHT. FORECAST CONFIDENCE...LOW TO MEDIUM. MOISTURE ACCOMPANYING WEAK FORCING FROM MID LEVEL SHORT WAVE OVER NORTHWEST WISCONSIN CAUSED MID CLOUDS TO EXPAND OVER SOUTHEAST WI OVERNIGHT. LATEST RUC CARRIES THIS WEAK WAVE ACROSS SRN WI EARLY THIS MORNING. WATER VAPOR IMAGERY SHOWS SECOND WEAK WAVE OVER FAR NORTH CENTRAL MN WHICH MOVES ON A SIMILAR TRACK ACROSS CENTRAL AND SRN WI LATER THIS MRNG AND AFTN. WATER VAPOR IMAGERY AND 11-3.9 MICRON IMAGERY SHOWING MID-LEVEL MOISTURE AND CLOUDS ACCOMPANYING BOTH OF THESE WAVES. WITH INCREASING CYCLONIC CURVATURE IN THE LOW TO MID LEVELS...AND LINGERING THERMAL TROF...EXPECTING MORE CLOUDS THAN SUN OVER ERN CWA...WITH MORE OF A BALANCE IN THE WEST. FOR NOW WL HOLD OFF ON M/CLDY WORDING AS EXPECTING SEVERAL PERIODS OF AT LEAST P/SUNNY CONDITIONS TODAY. WL DROP DODGE AND JEFFERSON COUNTIES FROM FREEZE WARNING EARLY THIS MRNG AS BKN-OVC SHOULD LINGER IN THESE AREAS PREVENTING TEMPS FROM DROPPING INTO THE UPPER 20S. WITH KBUU AND KJVL IN THE LOW 30S...WL CONTINUE FREEZE WARNING IN WALWORTH COUNTY AND POINTS WEST UNTIL 14Z. CLOUDS AND BREEZY NORTHWEST WINDS WL ONLY ALLOW DAYTIME TEMPS TO RISE INTO THE MID TO UPPER 40S TODAY. INCREASING SUBSIDENCE FROM PASSING LEFT ENTRANCE REGION OF UPPER JET SHOULD HELP TO BREAK UP THE CLOUDS OVER SOUTH CENTRAL WI BUT SCT-BKN CLOUDS MAY HANG ON IN THE EAST AS ANOTHER WEAK WAVE ROTATES AROUND UPPER LOW OVER ONTARIO CANADA. ALSO...LOW LEVEL FLOW TURNS TO THE NORTH TO NORTHEAST OVER THE LAKESHORE AREAS WITH THE DELTA-T AROUND 12C. HENCE WITH CLEARING IN THE WEST AND SLIGHTLY LIGHTER WINDS...TEMPS LIKELY TO FALL BACK INTO THE UPPER 20S TO LOW 30S. DUE TO UNCERTAINTY REGARDING CLOUDS AND TEMPS FALLING TO 28F OR LOWER LATER TONIGHT...HELD OFF ON ISSUING ANOTHER FREEZE WARNING FOR LATE TONIGHT AWAY FROM THE LAKE. ALSO...REMOVED FROST WORDING TONIGHT DUE TO TEMP/DEWPOINT DEPRESSIONS REMAINING HIGH. .SHORT TERM...WEDNESDAY THROUGH THURSDAY NIGHT. WEDNESDAY AND WEDNESDAY NIGHT...FORECAST CONFIDENCE HIGH. TEMPERATURES REMAIN THE FOCUS AS CURRENT RELATIVELY COLD TREND CONTINUES WITH WESTERN GREAT LAKES IN NORTHERLY FLOW BETWEEN EASTERN TROUGH AND PLAINS RIDGE. WINDS TURN MORE NORTHERLY FOR WEDNESDAY...BUT 925MB TEMPERATURES MODIFY A BIT UPWARD WITH DRY ADIABATIC MIXING TO THAT LEVEL BRINGING HIGHS BACK INTO THE LOWER TO MIDDLE 50S INLAND...WITH NORTH-NORTHEAST WINDS AND POTENTIAL FOR LAKE STRATOCUMULUS HOLDING READINGS IN THE 40S. WEAK...SHEARED VORTICITY ON PERIPHERY OF CYCLONIC FLOW SOUTH AND WEST OF STATE SHIFTS BACK EAST ACROSS STATE OVERNIGHT WEDNESDAY. ECMWF AN OUTLIER...BRINGING A STRONG VORT SOUTHEAST FROM NWRN MN...REACHING SW WI/NW IL AROUND 06Z THURSDAY. HOWEVER COLUMN REMAINS DRY ON ECMWF FORECAST SOUNDINGS SO NO POP...AND LITTLE TO NO CLOUDS. LIGHT WINDS AND CLEAR SKIES WILL BRING SUB-FREEZING LOW TEMPERATURES TO ALL BUT THE IMMEDIATE LAKESHORE AREAS. WILL HAVE PATCHY FROST...AND AREAS OF FROST WHERE LOW TEMPS FALL BELOW 30F. THURSDAY THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE TEMPERATURES CONTINUE TO WARM THURSDAY AS 850-700 MB RIDGE AXES SHIFT EAST. SURFACE HIGH ALSO CENTERED OVER THE EASTERN LAKES BY 00Z FRIDAY...WITH SOUTH WINDS BY THE AFTERNOON WEST AND SOUTHEAST WINDS ALL DAY IN THE EAST. BLENDED SOLUTION BRINGS UPPER 50S TO LOWER 60S WEST...WITH LOW TO MID 50S EAST. NAM AND GFS BRING PRECIPITATION INTO THE WEST BETWEEN 06Z AND 12Z FRIDAY WITH 850-700MB WARM AIR ADVECTION/MOISTURE TRANSPORT. WILL TIME PRECIPITATION ACROSS CWA WITH BEST ISENTROPIC ADIABATIC OMEGA AND LOWER CONDENSATION PRESSURE DEFICITS. LOWS BETWEEN 06Z AND 09Z FRIDAY...THEN STEADY OR SLOWLY WARM WITH WARM ADVECTION AND INCREASING CLOUDS. .LONG TERM...FRIDAY THROUGH MONDAY. FORECAST CONFIDENCE MEDIUM. A WET END OF THE WEEK/BEGINNING OF THE WEEK AS SERIES OF SHORT WAVE TROUGHS EJECT FROM WESTERN TROUGH. SOME PLACEMENT/TIMING DIFFERENCES WHICH MAY IMPACT TEMPERATURES AND STORM MODE...BUT CONSENSUS BLEND BRINGS SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS WITH WAA FRIDAY/FRIDAY NIGHT...THEN A CHANCE OF THUNDERSTORMS SATURDAY... BECOMING LIKELY SATURDAY NIGHT WITH ADDITIONAL FORCING WITH SHORT WAVE...TAPERING OFF TO SHOWERS WITH BAROCLINIC ZONE AND COOLER AIR DROPPING SOUTH BEHIND WAVE SUNDAY NIGHT AND MONDAY. MAINLY DRY MONDAY NIGHT...BUT SECONDARY WAVE ALONG BAROCLINIC ZONE MAY BRUSH THE SOUTHEAST TUESDAY/TUESDAY NIGHT. && .AVIATION/12Z TAFS/...PERIODS OF MOSTLY VFR CLOUDS EXPCD TODAY AND MOSTLY ERN AREAS TONIGHT. SCT CLOUDS MAY APPROACH 3K FEET FOR A TIME TODAY AND IN THE EAST TNGT AS THE LOW LEVEL FLOW BECOMES MORE NLY. ANOTHER GUSTY DAY ANTICIPATED...BUT SHOULD NOT BE AS STRONG AS LAST SEVERAL DAYS. OCCASIONAL GUSTS TO AROUND 25KTS LATER THIS MRNG AND AFTN. && .MARINE...COLD AIR WILL REMAIN ANCHORED OVER LAKE MICHIGAN FOR THE NEXT 24 HOURS. MODIS IMAGERY FROM 17Z/09 MEASURED LAKE SURFACE TEMPS 4-5C AWAY FROM THE SHALLOWER NEARSHORE WATERS...CONFIRMED BY SOUTH LAKE BUOY TEMP. RESULTANT UNSTABLE CONDITIONS OVER THE LAKE AS WELL AS OVER THE LAKESHORE AREAS...WILL ALLOW GUSTY WINDS TO AFFECT THE NEAR SHORE WATERS. OCCASIONAL GUSTS TO 25 KTS ARE EXPECTED LATER THIS MRNG AND AFTN...LINGERING INTO THE EARLY EVE. WL EXTEND ONGOING SMALL CRAFT ADVY SEVERAL HOURS INTO THE EVE TO ALLOW FOR DIMINISHING GUSTINESS. WINDS WL REMAIN GUSTY TNGT...BUT SHOULD SUBSIDE BELOW ADVY CRITERIA. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...FREEZE WARNING UNTIL 9 AM CDT THIS MORNING FOR WIZ046-047-056- 057-062-063-067>070. LM...SMALL CRAFT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR LMZ643>646. && $$ TODAY/TONIGHT AND AVIATION/MARINE...MBK WEDNESDAY THROUGH MONDAY...REM ______________________________________________________________________ KMKX - Reference: ['michigan...winds remain southeast. latest modis imagery from around '] 254 FXUS63 KMKX 130830 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 330 AM CDT FRI APR 13 2012 .TODAY AND TONIGHT...FORECAST CONFIDENCE - MEDIUM. PULLED TRIGGER ON DENSE FOG ADVY FOR SHEBOYGAN AND WASHINGTON COUNTIES. EVENING CLEARING ALLOWED TEMPS TO RAPIDLY COOL IN THESE AREAS TO DEWPTS. COLD SFC TEMPS AMPLIFIED LOW LEVEL INVERSION WHICH SHOULD PREVENT INCREASING WINDS DUE TO TIGHTENING PRESSURE GRADIENT TO AFFECT SFC IN THESE AREAS UNTIL AFT SUNRISE. DOT WEBCAMS SHOW DENSE FOG IS SPREADING IN HIGHWAY 43 AREA...AND SHERIFFS DISPATCH FOR SHEBOYGAN COUNTY REPORTING WIDESPREAD DENSE FOG. NRN PART OF WASHINGTON COUNTY ALSO EXPERIENCE AREAS OF DENSE FOG. EXPECT DENSE FOG TO QUICKLY THIN AFTER 12-13Z. WL LEAN MORE ON CONSISTENT ECMWF AND GFS SOLUTIONS FOR TODAY...AS LAST SEVERAL RUNS OF THE NAM HAVE BEEN ADJUSTING TO THESE SOLUTIONS. MID-LEVEL PROTECTIVE RIDGE MOVES SLOWLY EASTWARD TODAY AS WARM ADVECTION AHEAD OF PLAINS LOW PRESSURE SPREADS INTO WISCONSIN. MAIN SHORT WAVE OVER CENTRAL NE REMAINS WELL WEST OF SRN WI TODAY...HOWEVER WIND PROFILER NETWORK PICKS UP WEAKER SHORT WAVE FARTHER EAST OVER ERN KS WHICH TRACKS NORTHEAST ACROSS SRN WI LATER TODAY. SRN WI GETS BRUSHED WITH MODERATE WARM AIR ADVECTION LATE THIS MORNING AND AFTERNOON...WHICH IS TIED TO IMPRESSIVE LOW LEVEL THETA-E ADVECTION. PWAT VALUES INCREASE ONE HALF TO THREE QUARTERS INCH TODAY. STRONGEST Q-VECTOR CONVERGENCE OF -10 TO -20 UNITS FROM GFS BRUSHES WESTERN CWA LATER TODAY...SO WILL HANG ONTO LIKELY WORDING IN THIS AREA...AND KEEP CHANCE GRADIENT FARTHER EAST. DESPITE WARMER START TO DAY MOST AREAS...CLOUDS AND SOUTHEAST WINDS WILL KEEP TEMPS SOMEWHAT IN CHECK...WITH EXPECTED HIGH TEMPS AROUND YESTERDAYS READINGS. SHEBOYGAN AND PORT WASHINGTON WILL LIKELY BE A FEW DEGREES COOLER. ELEVATED INSTABILITY INCREASES THIS AFTN...SO WL CONTINUE TO MENTION THUNDER POTENTIAL...ESPECIALLY WITH SURGE OF THETA-E ADVECTION. WL HANG ONTO CHANCE POPS THIS EVENING AS WEAKENING SHORT WAVE MOVES ACROSS CENTRAL AND NORTHERN WI. WL TREND DOWNWARD WITH POPS FOR LATER TONIGHT AS DRIER AIR IN THE MID-LEVELS SWEEPS IN FROM THE WEST. INCREASING SLY FLOW HOWEVER WL PULL DEEPER LOW LEVEL RH INTO THE AREA FOR TNGT...RESULTING IN THICKENING CLOUDS AND POSSIBLY PATCHY LIGHT RAIN OR DRIZZLE. .SATURDAY AND SUNDAY...FORECAST CONFIDENCE...MEDIUM VERY ACTIVE PATTERN EXPECTED FOR THE WEEKEND...WITH SHOWERS AND THUNDERSTORMS EXPECTED. SURFACE LOW PRESSURE JUST NORTH OF MINNESOTA SAT MORNING WILL CONTINUE MOVING EAST NORTHEAST DURING THE DAY...WHILE ANOTHER LOW DEEPENS WELL TO THE SOUTHWEST. MAY BE RELATIVELY QUIET DURING THE DAY SATURDAY BETWEEN SYSTEMS...BUT WARM ADVECTION MAY BRING A SHOWERS AND STORMS BY LATE AFTERNOON. WITH 925 MB TEMPS IN THE 15-16C RANGE...SHOULD GET INTO THE LOW 70S MOST PLACES...ESPECIALLY IF THE SUN COMES OUT AT ALL. BETTER CHANCE FOR SHOWERS AND STORMS COMES SAT EVENING AND OVERNIGHT AS THE WARM FRONT LIFTS THROUGH SOUTHERN WISCONSIN. STRONG LOW LEVEL JET PUSHES INTO THE AREA WITH PLENTY OF SHEAR EXPECTED TO GO ALONG WITH AROUND 1000 J/KG OF ELEVATED CAPE. THUS THINK SOME OF THE STORMS MAY BE STRONG TO SEVERE...WITH SPC NOSING THE SLIGHT RISK JUST INTO THE SW FORECAST AREA. MODELS IN BETTER AGREEMENT NOW BRINGING SFC LOW TO AROUND THE BORDER OF SOUTHEAST MINNESOTA AND WEST CENTRAL WISCONSIN BY SUNDAY EVENING. STRONG LOW LEVEL JET EXPECTED TO NOSE RIGHT INTO SRN WI...WITH MODELS GENERALLY ALL KEEPING SFC WARM FRONT NORTH OF THE FORECAST AREA. CAPE VALUES GET BACK UP TO AROUND 1000 J/KG DURING THE DAY...WITH A TON OF SHEAR AGAIN...ON THE ORDER OF 50-70 KNOTS OF 0-6 KM BULK SHEAR. CERTAINLY A THREAT OF SEVERE STORMS AS THE COLD FRONT APPROACHES...AND SPC HAS THE ENTIRE FORECAST AREA UNDER A SLIGHT RISK. WILL BE MILD AGAIN SUNDAY WITH THE FORECAST AREA IN THE WARM SECTOR. AMOUNT OF CLOUDS AND TIMING OF PRECIP WILL DETERMINE HOW WARM IT GETS...BUT LOW OR EVEN MID 70S SEEMS REASONABLE...WITH UPPER 70S NOT OUT OF THE QUESTION WITH SOME SUNSHINE. FRONT TO MOVE THROUGH SUNDAY NIGHT...WITH CHANCE FOR PRECIP WINDING DOWN AFTER MIDNIGHT. .MONDAY AND TUESDAY...FORECAST CONFIDENCE...MEDIUM KEPT CHANCE POPS ON MONDAY INTO MONDAY NIGHT WITH TRAILING PRECIP ON THE BACK SIDE OF THE SFC LOW...ALONG UPPER TROUGH AXIS. COLD AIR WILL FILTER IN BEHIND THE SYSTEM...WITH LOWS DROPPING INTO 30S MONDAY NIGHT AND HIGHS STRUGGLING TO HIT 50 TUESDAY. SHOULD BE DRY TUESDAY WITH SFC HIGH PRESSURE OVERHEAD. .WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...LOW TO MEDIUM HAVE SOME LOW POPS FOR MID WEEK...AS MODELS ALL GENERALLY SHOW LOW PRESSURE MOVING THOUGH THE AREA AT SOME POINT. TIMING/PLACEMENT DIFFERENCES BETWEEN MODELS RESULTING INTO LOWER CONFIDENCE IN POPS FOR INDIVIDUAL PERIODS...THOUGH PRECIP AT SOME POINT MID WEEK SEEMS REASONABLE. SHOULD SEE TEMPS BACK TOWARD NORMAL FOR WEDNESDAY AND THURSDAY. && .AVIATION/12Z TAFS/...GRADUALLY THICKENING CLOUDS TODAY BUT DRY SOUTHEAST FLOW SHOULD KEEP CIGS VFR DESPITE INCREASING -SHRA THREAT LATE MRNG AND AFTN. ELEVATED INSTABILITY REMAINS MINIMAL THIS AFTN SO WL HOLD OFF FROM INTRODUCING THUNDER IN TAFS AT THIS POINT. CONTINUED DEEP MOISTURE TRANSPORT FROM SLY WINDS WL USHER DEEPER RH IN TNGT...WITH LIKELY MVFR CIGS. && .MARINE...DESPITE TIGHTENING PRESSURE GRADIENT TODAY OVER LAKE MICHIGAN...WINDS REMAIN SOUTHEAST. LATEST MODIS IMAGERY FROM AROUND 18Z/12 SHOW LAKE SFC TEMPS BEYOND THE NEARSHORE WATERS REMAIN AROUND 5-6C. HENCE EXPC LOW LEVEL INVERSION OVER LAKE MI TODAY...WHICH SHOULD PREVENT STRONGER WINDS FROM MIXING DOWN TO LAKE SFC. WIND GUSTS WL EXCEED 22KTS HIGHER THAN 1K FEET OFF LAKE. SECOND STRONGER LOW PRESSURE SYSTEM MOVING THRU UPPER MIDWEST ON SUN WL RESULT IN A TIGHTER PRESSURE GRADIENT. WITH EXPCD WMFNT TO BE NORTH OF SRN LAKE MI...GUSTY SW WINDS WL LIKELY REACH SMALL CRAFT ADVY LEVELS FROM SAT NGT INTO SUN NGT. BETTER CHANCE FOR STRONG TO SEVERE TSTORMS WITH THIS SYSTEM AS WELL. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR WIZ052-060. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...MBK SATURDAY THROUGH THURSDAY...DDV ______________________________________________________________________ KMKX - Reference: ['modis imagery and mid lake buoy continue to show srn lake mi sfc '] 122 FXUS63 KMKX 290846 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 346 AM CDT SUN APR 29 2012 .SHORT TERM... TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM. DRIER AIR RIDING NORTHEAST BREEZES HAS RESULTED IN SCOURING OUT LOW CLOUDS ACROSS SOUTHERN WISCONSIN OVERNIGHT. HOWEVER DEEPER MOISTURE WILL NOT BE PUSHED FAR AS LOW LEVEL FLOW WL BE REMAINING SOUTHERLY JUST TO THE SOUTH IN SRN IA INTO NRN IL. PWAT VALUES WILL REMAIN AROUND AN INCH IN THESE AREAS. ALREADY SOME SCT -SHRA FORMING IN WEAK WARM AIR ADVECTION IN SE IOWA...BUT DRIER AIR SHOULD ERODE THESE -SHRA BEFORE MAKING INROADS INTO SRN WI. UPSTREAM SHORT WAVE VCNTY OF SOUTHEAST CO WL TRACK NORTHEAST ACROSS THE CENTRAL PLAINS TODAY AND ACROSS ERN IA AND WI TNGT. INCREASING SOUTHERLY WINDS AHEAD OF THIS FEATURE WILL PULL THIS DEEPER MOISTURE NORTHWARD INTO WI. IN FACT BOTH THE GFS AND NAM SHOW STRONGER LOW LEVEL THETA-E ADVECTION COMMENCING THIS AFTERNOON...PEAKING OVER SRN WI THIS EVENING BEFORE PUSHING OFF TO THE NORTHEAST. WL LEAN A LITTLE MORE ON CONSISTENT GFS AND ECMWF SOLUTIONS AS LATEST NAM TRENDING TOWARD SLIGHTLY FASTER SCENARIO IN CARRYING MID LEVEL WAVE INTO VCNTY OF NERN IA BY 00Z/MON. ALL SHORT TERM GUIDANCE IN GOOD AGREEMENT ON CARRYING ENHANCED SYNOPTIC SCALE FORCING ASSOCIATED WITH RIGHT ENTRANCE REGION OF JET ACROSS SOUTHERN WI LATE THIS AFTERNOON AND EVENING. ALL FACTORS COME TOGETHER DURING THE EVENING THROUGH THE EARLY MORNING HOURS BEFORE THE ENHANCED FORCING SLIDES OFF TO THE EAST BY 12Z. WL BUMP UP POPS TO CATEGORICAL ALL AREAS...WITH FAVORED PERIOD OF PRECIP IN THE WESTERN CWA DURING THE EVENING...AND SLIGHTLY LATER IN THE EASTERN CWA. ELEVATED INSTABILITY REMAINS LOW...BUT CAN NOT RULE OUT ISOLATED T DUE TO STRENGTH OF MOISTURE ADVECTION AND OMEGA. IN THE SHORT TERM...STILL EXPECT A WARMER DAY WITH FILTERED SUNSHINE...BUT HIGH CLOUDS WL CUT BACK A FEW DEGREES ON MAX T. ONSHORE FLOW WL KEEP LAKESHORE AREAS COOLER AS WELL. MONDAY AND MONDAY NIGHT...FORECAST CONFIDENCE MEDIUM. THE BULK OF THE PRECIP FORCING WILL HAVE SHIFTED SOUTHEAST OF WI BY 12Z MON...BUT KEPT LINGERING CHANCE OF SHOWERS WITH ISOLATED THUNDER POSSIBLE ACROSS FAR SOUTHERN WI THROUGH MID MORNING...THEN TAPERED OFF THE CHANCES TO DRY IN THE AFTERNOON. DESPITE THE RAIN ENDING...MODELS ARE BECOMING MORE CONSISTENT IN KEEPING SKIES CLOUDY THROUGH THE DAY AND EVEN INTO MON NIGHT AS ADDITIONAL 500MB SHORTWAVES ROLL ACROSS SOUTHERN WI IN THE FAST ZONAL FLOW. THE EASTERLY WIND COMPONENT NEAR THE LAKE WILL KEEP TEMPERATURES EVEN COOLER IN THE EAST. EXPECTING MAX TEMPS TO BE BELOW GUIDANCE... RANGING FROM THE MID 50S NEAR THE LAKESHORE TO THE LOWER 60S WELL INLAND. WEAK RIDGING AND SUBSIDENCE WITH THE LEFT ENTRANCE REGION OF THE UPPER JET WILL KEEP THINGS DRY MON NIGHT BUT CANNOT RULE OUT CLOUDS WITH THE LINGERING LOW LEVEL MOISTURE. TUESDAY AND TUESDAY NIGHT...FORECAST CONFIDENCE MEDIUM. FLOW BACKS TO THE SW ON TUESDAY AHEAD OF A DEVELOPING BROAD...LOW AMPLITUDE WESTERN TROUGH. THE NEXT CHANCE FOR THUNDERSTORMS SHOULD NOW HOLD OFF UNTIL TUE EVENING. THERE IS REALLY NOT STRONG FORCING FOR THIS NEXT CHANCE...SO BACKED OFF ON POPS TO CHANCE INSTEAD OF LIKELY...WITH THE BETTER CHANCE PROBABLY AFTER MIDNIGHT. THE NOSE OF THE LOW LEVEL JET /LLJ/ POINTS INTO SOUTHERN WI TUE NIGHT...WEAK SHORTWAVES CONTINUE TO ROLL ACROSS WI...AND SOUTHERN WI IS VAGUELY WITHIN A RIGHT ENTRANCE REGION OF THE UPPER JET DURING THIS TIME. .LONG TERM... WEDNESDAY THROUGH THURSDAY...FORECAST CONFIDENCE MEDIUM. TEMPERATURES ARE EXPECTED TO WARM INTO THE 70S INLAND ON TUESDAY...AND THEN INTO THE UPPER 70S ON GUSTY SOUTHWEST WINDS WEDNESDAY. CAPE INCREASES BY 00Z THU TO ALMOST 1500 J/KG...WITH LIFTED INDEX AROUND -7...DECENT SHEAR AND A BULK RICHARDSON NUMBER AROUND 40 PER THE GFS MODEL. THE CIPS WARM SEASON ANALOG SHOWS A 40 PERCENT CHANCE FOR SEVERE HAIL AND WIND BASED ON PREVIOUS SEVERE WEATHER REPORTS FROM PAST SIMILAR WEATHER PATTERNS...AS WELL AS A CHANCE FOR TORNADOES. SPC HAD SOUTHEAST WI MARKED IN A SEVERE WEATHER THREAT IN THEIR SAT MORNING EXTENDED CONVECTIVE OUTLOOK. THE SEVERE WEATHER PARAMETER PRODUCT /CWASP/ IN OUR OFFICE SHOWS MUCH OF WI IN THE 60 TO 70 PERCENT RANGE FOR SEVERE WEATHER. SOUTHERN WI WILL REMAIN IN THE WARM SECTOR AND ADDITIONAL SHORTWAVES ALONG WITH THE RIGHT ENTRANCE REGION OF THE JET WILL CONTINUE ITS TRACK OVERHEAD...THUS ALLOWING FOR THE SEVERE WEATHER POTENTIAL TO PERSIST INTO THURSDAY AFTERNOON. WE WILL CONTINUE TO MONITOR THE SEVERE WEATHER THREAT FOR WED/WED NIGHT AND ALSO FOR THU. STAY TUNED. THURSDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE LOW. THE ECMWF AND CANADIAN MODELS THEN SHIFT THE BAROCLINIC ZONE SOUTH OF WI THU NIGHT WHILE THE GFS KEEPS IT ACROSS SOUTHERN WI SO THERE IS MUCH MORE UNCERTAINTY IN PRECIP CHANCES AND TEMPERATURES IN THE EXTENDED PERIODS. && .AVIATION/12Z TAFS/... NORTHEAST BREEZES CONTINUE TO CARRY DRIER LOW LEVEL AIR ACROSS SOUTHEAST WISCONSIN RESULTING IN SCOURING LOW CLOUDS. EXPC VFR CONDITIONS TO CONTINUE TODAY WITH BKN-OVC MID-HIGH LEVEL CLOUDS. SHRA EXPCD TO OVERSPREAD SRN WI TONIGHT RESULTING IN LOWERING CIGS AND VSBYS. EXPC CIGS TO DROP TO AT LEAST MVFR TNGT...AND POSSIBLY LOWER BY MON MRNG. && .MARINE... WEAK LOW PRESSURE PASSING TO THE SOUTH OF LAKE MI TONIGHT AND MONDAY WILL RESULT IN A TIGHTENING PRESSURE GRADIENT. SURFACE WINDS ARE EXPECTED TO REMAIN ONSHORE RESULTING IN LOW LEVEL INVERSION. LATEST MODIS IMAGERY AND MID LAKE BUOY CONTINUE TO SHOW SRN LAKE MI SFC TEMPS IN THE LOW TO MID 40S. EXPC INVERSION TO PREVENT STRONGER WINDS FROM REACHING LAKE SURFACE TNGT. HOWEVER...WIND GUSTS EXCEEDING 20KTS MAY BE FELT AT SGNW3 AND KNSW3 WHERE ANEMOMETER HEIGHTS ARE 60FT ABV LAKE SFC. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...MBK MONDAY THROUGH SATURDAY...MRC ______________________________________________________________________ KMKX - Reference: ['.marine...latest modis sea surface temperature imagery from monday '] 613 FXUS63 KMKX 150846 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 346 AM CDT TUE MAY 15 2012 .SHORT TERM... TODAY AND TONIGHT - CONFIDENCE...MEDIUM TO HIGH. GOES SOUNDER SHOWS PWAT VALUES AROUND 0.6 INCH ACROSS THE AREA WHILE UPSTREAM...PWATS DROP TO AROUND 0.25 INCH BEHIND SFC COLD FRONT. ALL SHORT TERM GUIDANCE IN GOOD AGREEMENT ON CARRYING SFC COLD FRONT ACROSS CWA THIS AFTERNOON...EXITING FAR SOUTHEAST BY EARLY EVENING. PWAT AND WATER VAPOR IMAGERY REVEALS PRESENCE OF MID-LEVEL MOISTURE AND OVER LAST SEVERAL HOURS...HAVE BEGUN TO SEE 45 TO 50 DEGREE DEWPTS IN THE PLAINS MOVE SLOWLY NORTHWARD TOWARD WI. MODEL FORECASTED DEWPTS FOR TODAY CONTINUE TO BE 5 TO 10 DEGREES TOO WARM...HOWEVER AGREE WITH SPC THAT SFC DEWPTS COULD CLIMB INTO THE LOW 50S THIS AFTN. EXAMINATION OF FORECAST SOUNDINGS WITH THIS LOW LEVEL MOISTURE DOES REVEAL POTENTIAL FOR MUCAPE REACHING 1500-2000 J/KG DURING PEAK HEATING AS THE COLD FRONT SLIDES THROUGH THE AREA. LOW LEVEL CONVERGENCE NOT GREAT DUE TO SOUTHWEST WINDS AHEAD OF THE FRONT. HOWEVER SRN WI DOES GET CLIPPED BY SYNOPTIC SCALE FORCING CAUSED BY SECOND VIGOROUS MID-LEVEL SHORT WAVE CURRENTLY NEAR SRN END OF LAKE WINNIPEG. AXIS OF 10 UNIT LAYER Q-VECTOR CONVERGENCE SWEEPS THRU SRN WI DURING THE AFTN...ALONG WITH LOW LEVEL FN VECTOR RESPONSE TO FRONTOGENESIS. BEST THREAT WILL BE IN THE LATE AFTN ALONG THE FRONT IN THE SOUTHEAST CWA...SO WENT WITH SCT WORDING. BULK SHEAR OF 35 TO 45 KTS AND INSTABILITY MAY ALLOW THE TSTORMS THAT DUE DEVELOP POSSIBLY TAKE ON SUPERCELLULAR CHARACTERISTICS. HIGH LCL SHOULD PREVENT TORNADO FORMATION...AS DAMAGING WINDS AND HAIL WOULD BE SEVERE WEATHER THREATS. SVR THREAT WOULD BE BRIEF. DRY SOUTHWEST FLOW AND PARTLY TO MOSTLY SUNNY SKIES FOR MUCH OF THE DAY WL RESULT IN TEMPERATURES CLIMBING INTO THE LOW TO MID 80S MOST AREAS. BREEZY SOUTHWEST WINDS WL PREVENT LAKE BREEZE...SO WL BE WARM AT THE SHORE AS WELL. HOWEVER LAKE MI BEACH GOERS WL NEED TO WATCH FOR RAPID COOLING EARLY THIS EVENING AS WINDS VEER STRONGLY TO THE NORTHEAST. WEDNESDAY THROUGH THURSDAY...FORECAST CONFIDENCE...MEDIUM. MAX TEMPS WILL BE 15 TO 20 DEGREES COOLER ON WED IN THE WAKE OF THE COLD FRONT. A LAKE BREEZE WILL KEEP THE LAKESHORE AREAS IN THE LOWER 60S. PLENTY OF SUNSHINE AND VERY LIGHT WINDS SHOULD ALLOW INLAND TEMPS TO APPROACH 70 BY LATE AFTERNOON. DEWPOINT TEMPS EXPECTED TO MIX DOWN INTO THE LOWER 30S. WARM AIR ADVECTION /WAA/ WILL BEGIN WED NIGHT AND PERSIST ACROSS WI THROUGH THU NIGHT AS SURFACE LOW PRESSURE ORGANIZES OVER THE PLAINS AND AN UPPER LEVEL RIDGE AMPLIFIES OVERHEAD. TEMPS WILL WARM INTO THE UPPER 60S/LOW TO MID 70S ON THU. EASTERLY COMPONENT TO THE SOUTHERLY WINDS WILL KEEP LAKESHORE AREAS A LITTLE COOLER. THERE SHOULD BE SOME MID CLOUDS WITH THE WAA AS WELL. THERE WILL NOT BE A LOT OF MOISTURE RETURN INTO SOUTHERN WI GIVEN THE SPRAWLING HIGH IN THE SOUTH CENTRAL U.S. AND MODELS SEEM TO KEEP OVERESTIMATING THE DEWPOINT TEMPS BY AT LEAST 5 DEGREES. THE MODELS ARE CONSISTENT IN GENERATING PRECIP WITH THE WAA...ALTHOUGH THE NAM AND GFS FOCUS IT IN NORTHERN WI WHILE THE ECMWF IS MORE TOWARD CENTRAL/SOUTHERN WI. KEPT THE SLIGHT CHANCE OF THUNDER IN THE FCST FOR NOW BUT MODELS ARE TRENDING FURTHER NORTH. .LONG TERM... FRIDAY THROUGH SATURDAY...FORECAST CONFIDENCE MEDIUM. THERE COULD BE A SHORTWAVE OR TWO ROUNDING THE UPPER LEVEL RIDGE THU NIGHT INTO FRI WHICH COULD GENERATE A THUNDERSTORM COMPLEX. THUS KEPT THE SLIGHT CHANCE POPS IN FOR FRI AS WELL. BY FRI AFTERNOON...IT LOOKS LIKE THE WARM FRONT WILL BE NORTH OF THE FORECAST AREA AND WE SHOULD BE CAPPED...WARM AND DRY THROUGH SATURDAY. THE GFS HAS COOLER TEMPS FOR FRI AND SAT SO TRENDED TOWARD THE WARMER ECMWF AND CANADIAN...WITH MAX TEMPS IN THE LOWER 80S INLAND FROM THE LAKE. SUNDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM. THE COLD FRONT COULD MAKE IT INTO WI AS EARLY AS LATE SAT NIGHT SO THEREFORE MENTIONED THE SLIGHT CHANCE FOR THUNDER. HOWEVER...THE BETTER CHANCE FOR THE FRONTAL PASSAGE WITH THUNDERSTORMS WILL HOLD OFF UNTIL SUNDAY AFTERNOON/SUNDAY NIGHT. THE GFS IS QUICKEST AND THE ECMWF IS SLOWEST. THIS FAR OUT THE TIMING IS QUESTIONABLE SO WILL HAVE TO SPREAD THE CHANCES OF PRECIPITATION ACROSS THESE TWO DAYS...ALTHOUGH THE ACTUAL DURATION WOULD BE LESS THAN A 12 HOUR WINDOW. TUESDAY...FORECAST CONFIDENCE MEDIUM TO HIGH. TUESDAY WILL BE COOLER IN THE WAKE OF THE FRONT...SIMILAR TO THE TEMP DIFFERENCE EXPECTED BETWEEN TODAY AND WEDNESDAY. && .AVIATION/12Z TAFS/...A BREEZY DAY IS EXPECTED WITH WIND GUSTS TO 25KTS BY LATE MRNG INTO THE AFTERNOON BEFORE A COLD FRONT NOW ENTERING FAR NORTHWEST WISCONSIN SWEEPS THROUGH THE SOUTH. EXPC THE WIND SHIFT ASSOCIATED WITH THE FRONT BETWEEN 21Z AND 02Z AT THE TAF SITES. ISOLD TO SCT THUNDER MAY AFFECT THE TAF SITES FOR AN HOUR OR TWO DURING THIS PERIOD AS WELL. WL NEED TO WATCH FOR WIND GUSTS POTENTIALLY REACHING 40-50KTS NEAR THOSE STORMS LATE THIS AFTN. LOW LEVELS REMAIN DRY SO VFR CONDITIONS EXPECTED THROUGH THE PERIOD. && .MARINE...LATEST MODIS SEA SURFACE TEMPERATURE IMAGERY FROM MONDAY AFTERNOON REVEALED LARGE TEMP GRADIENT ACROSS LAKE MI. FAR SOUTHERN PORTION OF THE LAKE HAD SST IN THE MID 60S WHILE LARGE EXPANSE OF THE NORTH AND CENTRAL SECTIONS REMAINED IN THE MID 40S. SUNSHINE AND STEEP LOW LEVEL LAPSE RATES WILL RESULT IN STRONG LOW LEVEL MIXING LATE THIS MRNG AND AFTN AHEAD OF APPROACHING COLD FRONT. WIND GUSTS ARE EXPECTED TO REACH 25KTS OVER THE SHORE AREAS DUE TO THE LOW LEVEL MIXING...HENCE A SMALL CRAFT ADVY WL BE POSTED. GUSTINESS WL DIMINISH FARTHER OUT INTO THE LAKE...WHERE COOLER LAKE WATERS WL RESULT IN LOW LEVEL INVERSION. COLD FRONT WL SWEEP RAPIDLY ACROSS THE NEARSHORE WATERS FROM 22Z THROUGH 02Z...WITH WINDS TURNING RAPIDLY TO THE NNE BEHIND THE FRONT. THE SST TEMPERATURE GRADIENT ACROSS THE LAKE WILL CAUSE THIS COLD FRONT TO ACT AS A PNEUMONIA FRONT...AND WILL RESULT IN THE RAPID WIND SHIFT...SIGNIFICANT DROP IN SFC TEMP...RISE IN PRESSURE AND POTENTIALLY A BRIEF PERIOD OF GUSTS TO 30KTS DURING THIS FOUR HOUR PERIOD. HENCE WL CONTINUE SMALL CRAFT ADVY INTO THE EVENING TO ACCOUNT FOR THESE CHANGEABLE CONDITIONS. THE WINDS WL SETTLE DOWN BY LATE EVENING AS THE FRONT PUSHES FARTHER TO THE SOUTH AND EAST. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO MIDNIGHT CDT TONIGHT FOR LMZ643>646. && $$ TODAY/TONIGHT AND AVIATION/MARINE...MBK WEDNESDAY THROUGH MONDAY...MRC ______________________________________________________________________ KMKX - Reference: ['marine...latest modis sea surface temperature imagery from monday '] 786 FXUS63 KMKX 151747 AAA AFDMKX AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 1247 PM CDT TUE MAY 15 2012 .UPDATE...SFC COLD FRONT IS STILL ANTICIPATED TO PASS THROUGH OUR CWA THIS AFTERNOON. VIS SAT SHOWS MID AND HIGH CLOUDS STARTING TO WORK INTO THE CWA...THOUGH SHOULD NOT INHIBIT TODAY\S HIGHS. INHERITED TEMPS AND SKIES ARE ON TRACK. THE MAIN CONCERN IS IN REGARD TO CONVECTIVE DEVELOPMENT OR PRECIP THIS AFTERNOON...AFTER 18 UTC. CHANCE/SLIGHT CHANCE POPS WERE KEPT GIVEN UNCERTAINTY AND LACK OF MOISTURE...AS SEEN BY LOW PWAT VALUES AND MODEL FCST/12Z SOUNDINGS...AND WEAK LOW-LEVEL CONVERGENCE. FURTHERMORE...UNCERTAINTY EXISTS GIVEN DIFFERENCES IN MODEL SOUNDINGS...SPECIFICALLY NAM AND RAP...AND HOW THEY MIX DEWPOINTS. && .AVIATION/18Z TAFS/...PREVAILING VFR CONDITIONS EXPECTED THROUGH WEDNESDAY. MAIN CONCERN THIS AFTERNOON INTO EVENING IS POSSIBLE THUNDERSTORM DEVELOPMENT AS A COLD FRONT APPROACHES. PRETTY DRY IN THE LOWER LEVELS THOUGH...WITH MODELS ALL GENERALLY OVERDOING DEWPOINTS. THUS STILL NOT EXCITED AT THE CHANCE FOR WIDESPREAD SHOWERS AND STORMS...SO OPTED TO JUST MAINTAIN VCTS IN TAFS. CLEARING SKIES EXPECTED TONIGHT BEHIND THE COLD FRONT...WITH MAINLY HIGH CLOUDS ON WEDNESDAY. && .PREV DISCUSSION... /ISSUED 346 AM CDT TUE MAY 15 2012/ SHORT TERM... TODAY AND TONIGHT - CONFIDENCE...MEDIUM TO HIGH. GOES SOUNDER SHOWS PWAT VALUES AROUND 0.6 INCH ACROSS THE AREA WHILE UPSTREAM...PWATS DROP TO AROUND 0.25 INCH BEHIND SFC COLD FRONT. ALL SHORT TERM GUIDANCE IN GOOD AGREEMENT ON CARRYING SFC COLD FRONT ACROSS CWA THIS AFTERNOON...EXITING FAR SOUTHEAST BY EARLY EVENING. PWAT AND WATER VAPOR IMAGERY REVEALS PRESENCE OF MID-LEVEL MOISTURE AND OVER LAST SEVERAL HOURS...HAVE BEGUN TO SEE 45 TO 50 DEGREE DEWPTS IN THE PLAINS MOVE SLOWLY NORTHWARD TOWARD WI. MODEL FORECASTED DEWPTS FOR TODAY CONTINUE TO BE 5 TO 10 DEGREES TOO WARM...HOWEVER AGREE WITH SPC THAT SFC DEWPTS COULD CLIMB INTO THE LOW 50S THIS AFTN. EXAMINATION OF FORECAST SOUNDINGS WITH THIS LOW LEVEL MOISTURE DOES REVEAL POTENTIAL FOR MUCAPE REACHING 1500-2000 J/KG DURING PEAK HEATING AS THE COLD FRONT SLIDES THROUGH THE AREA. LOW LEVEL CONVERGENCE NOT GREAT DUE TO SOUTHWEST WINDS AHEAD OF THE FRONT. HOWEVER SRN WI DOES GET CLIPPED BY SYNOPTIC SCALE FORCING CAUSED BY SECOND VIGOROUS MID-LEVEL SHORT WAVE CURRENTLY NEAR SRN END OF LAKE WINNIPEG. AXIS OF 10 UNIT LAYER Q-VECTOR CONVERGENCE SWEEPS THRU SRN WI DURING THE AFTN...ALONG WITH LOW LEVEL FN VECTOR RESPONSE TO FRONTOGENESIS. BEST THREAT WILL BE IN THE LATE AFTN ALONG THE FRONT IN THE SOUTHEAST CWA...SO WENT WITH SCT WORDING. BULK SHEAR OF 35 TO 45 KTS AND INSTABILITY MAY ALLOW THE TSTORMS THAT DUE DEVELOP POSSIBLY TAKE ON SUPERCELLULAR CHARACTERISTICS. HIGH LCL SHOULD PREVENT TORNADO FORMATION...AS DAMAGING WINDS AND HAIL WOULD BE SEVERE WEATHER THREATS. SVR THREAT WOULD BE BRIEF. DRY SOUTHWEST FLOW AND PARTLY TO MOSTLY SUNNY SKIES FOR MUCH OF THE DAY WL RESULT IN TEMPERATURES CLIMBING INTO THE LOW TO MID 80S MOST AREAS. BREEZY SOUTHWEST WINDS WL PREVENT LAKE BREEZE...SO WL BE WARM AT THE SHORE AS WELL. HOWEVER LAKE MI BEACH GOERS WL NEED TO WATCH FOR RAPID COOLING EARLY THIS EVENING AS WINDS VEER STRONGLY TO THE NORTHEAST. WEDNESDAY THROUGH THURSDAY...FORECAST CONFIDENCE...MEDIUM. MAX TEMPS WILL BE 15 TO 20 DEGREES COOLER ON WED IN THE WAKE OF THE COLD FRONT. A LAKE BREEZE WILL KEEP THE LAKESHORE AREAS IN THE LOWER 60S. PLENTY OF SUNSHINE AND VERY LIGHT WINDS SHOULD ALLOW INLAND TEMPS TO APPROACH 70 BY LATE AFTERNOON. DEWPOINT TEMPS EXPECTED TO MIX DOWN INTO THE LOWER 30S. WARM AIR ADVECTION /WAA/ WILL BEGIN WED NIGHT AND PERSIST ACROSS WI THROUGH THU NIGHT AS SURFACE LOW PRESSURE ORGANIZES OVER THE PLAINS AND AN UPPER LEVEL RIDGE AMPLIFIES OVERHEAD. TEMPS WILL WARM INTO THE UPPER 60S/LOW TO MID 70S ON THU. EASTERLY COMPONENT TO THE SOUTHERLY WINDS WILL KEEP LAKESHORE AREAS A LITTLE COOLER. THERE SHOULD BE SOME MID CLOUDS WITH THE WAA AS WELL. THERE WILL NOT BE A LOT OF MOISTURE RETURN INTO SOUTHERN WI GIVEN THE SPRAWLING HIGH IN THE SOUTH CENTRAL U.S. AND MODELS SEEM TO KEEP OVERESTIMATING THE DEWPOINT TEMPS BY AT LEAST 5 DEGREES. THE MODELS ARE CONSISTENT IN GENERATING PRECIP WITH THE WAA...ALTHOUGH THE NAM AND GFS FOCUS IT IN NORTHERN WI WHILE THE ECMWF IS MORE TOWARD CENTRAL/SOUTHERN WI. KEPT THE SLIGHT CHANCE OF THUNDER IN THE FCST FOR NOW BUT MODELS ARE TRENDING FURTHER NORTH. LONG TERM... FRIDAY THROUGH SATURDAY...FORECAST CONFIDENCE MEDIUM. THERE COULD BE A SHORTWAVE OR TWO ROUNDING THE UPPER LEVEL RIDGE THU NIGHT INTO FRI WHICH COULD GENERATE A THUNDERSTORM COMPLEX. THUS KEPT THE SLIGHT CHANCE POPS IN FOR FRI AS WELL. BY FRI AFTERNOON...IT LOOKS LIKE THE WARM FRONT WILL BE NORTH OF THE FORECAST AREA AND WE SHOULD BE CAPPED...WARM AND DRY THROUGH SATURDAY. THE GFS HAS COOLER TEMPS FOR FRI AND SAT SO TRENDED TOWARD THE WARMER ECMWF AND CANADIAN...WITH MAX TEMPS IN THE LOWER 80S INLAND FROM THE LAKE. SUNDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM. THE COLD FRONT COULD MAKE IT INTO WI AS EARLY AS LATE SAT NIGHT SO THEREFORE MENTIONED THE SLIGHT CHANCE FOR THUNDER. HOWEVER...THE BETTER CHANCE FOR THE FRONTAL PASSAGE WITH THUNDERSTORMS WILL HOLD OFF UNTIL SUNDAY AFTERNOON/SUNDAY NIGHT. THE GFS IS QUICKEST AND THE ECMWF IS SLOWEST. THIS FAR OUT THE TIMING IS QUESTIONABLE SO WILL HAVE TO SPREAD THE CHANCES OF PRECIPITATION ACROSS THESE TWO DAYS...ALTHOUGH THE ACTUAL DURATION WOULD BE LESS THAN A 12 HOUR WINDOW. TUESDAY...FORECAST CONFIDENCE MEDIUM TO HIGH. TUESDAY WILL BE COOLER IN THE WAKE OF THE FRONT...SIMILAR TO THE TEMP DIFFERENCE EXPECTED BETWEEN TODAY AND WEDNESDAY. AVIATION/12Z TAFS/...A BREEZY DAY IS EXPECTED WITH WIND GUSTS TO 25KTS BY LATE MRNG INTO THE AFTERNOON BEFORE A COLD FRONT NOW ENTERING FAR NORTHWEST WISCONSIN SWEEPS THROUGH THE SOUTH. EXPC THE WIND SHIFT ASSOCIATED WITH THE FRONT BETWEEN 21Z AND 02Z AT THE TAF SITES. ISOLD TO SCT THUNDER MAY AFFECT THE TAF SITES FOR AN HOUR OR TWO DURING THIS PERIOD AS WELL. WL NEED TO WATCH FOR WIND GUSTS POTENTIALLY REACHING 40-50KTS NEAR THOSE STORMS LATE THIS AFTN. LOW LEVELS REMAIN DRY SO VFR CONDITIONS EXPECTED THROUGH THE PERIOD. MARINE...LATEST MODIS SEA SURFACE TEMPERATURE IMAGERY FROM MONDAY AFTERNOON REVEALED LARGE TEMP GRADIENT ACROSS LAKE MI. FAR SOUTHERN PORTION OF THE LAKE HAD SST IN THE MID 60S WHILE LARGE EXPANSE OF THE NORTH AND CENTRAL SECTIONS REMAINED IN THE MID 40S. SUNSHINE AND STEEP LOW LEVEL LAPSE RATES WILL RESULT IN STRONG LOW LEVEL MIXING LATE THIS MRNG AND AFTN AHEAD OF APPROACHING COLD FRONT. WIND GUSTS ARE EXPECTED TO REACH 25KTS OVER THE SHORE AREAS DUE TO THE LOW LEVEL MIXING...HENCE A SMALL CRAFT ADVY WL BE POSTED. GUSTINESS WL DIMINISH FARTHER OUT INTO THE LAKE...WHERE COOLER LAKE WATERS WL RESULT IN LOW LEVEL INVERSION. COLD FRONT WL SWEEP RAPIDLY ACROSS THE NEARSHORE WATERS FROM 22Z THROUGH 02Z...WITH WINDS TURNING RAPIDLY TO THE NNE BEHIND THE FRONT. THE SST TEMPERATURE GRADIENT ACROSS THE LAKE WILL CAUSE THIS COLD FRONT TO ACT AS A PNEUMONIA FRONT...AND WILL RESULT IN THE RAPID WIND SHIFT...SIGNIFICANT DROP IN SFC TEMP...RISE IN PRESSURE AND POTENTIALLY A BRIEF PERIOD OF GUSTS TO 30KTS DURING THIS FOUR HOUR PERIOD. HENCE WL CONTINUE SMALL CRAFT ADVY INTO THE EVENING TO ACCOUNT FOR THESE CHANGEABLE CONDITIONS. THE WINDS WL SETTLE DOWN BY LATE EVENING AS THE FRONT PUSHES FARTHER TO THE SOUTH AND EAST. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR LMZ643>646. && $$ UPDATE...ET/DDV TODAY/TONIGHT AND AVIATION/MARINE...MBK WEDNESDAY THROUGH MONDAY...MRC ______________________________________________________________________ KMKX - Reference: ['rates. latest modis imagery from 03z/07 had mid-lake temps in the '] 327 FXUS63 KMKX 070825 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 325 AM CDT SAT JUL 7 2012 .TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM TO HIGH NO CHANGES PLANNED TO EXCESSIVE HEAT WARNING /EH.W/ HEADLINES FOR TODAY. SURFACE FRONT WILL CONTINUE TO SAG SOUTHWARD ACROSS REST OF SOUTHERN WI THRU MID-MRNG...SWITCHING WINDS TO THE NORTH TO NORTHEAST. COOLER...LESS HUMID AIR GRADUALLY SETTLES IN BEHIND THE FRONT...BUT WL TAKE ITS TIME ADVANCING INTO THE SOUTHWEST CWA. SUNSHINE AND LIGHT WINDS SHOULD ALLOW TEMPS IN THE SOUTHWEST TO REACH THE MIDDLE TO UPPER 90S MOST AREAS BY LATE MRNG...WHILE INCREASING CLOUDS...THE COOLER AIR AND STRONGER ONSHORE FLOW OFF LAKE MICHIGAN RESULT IN IN COOLER CONDITIONS ELSEWHERE. HENCE WL LET EH.W EXPIRE ACROSS THE NORTH AT 12Z AND IN THE SOUTHWEST DURING THE LATE AFTN. THIS AREA MAY BE ABLE TO BE CANCELLED EARLIER THIS AFTN. 925H TEMPS REMAIN IN THE UPPER 20S IN THE SOUTHWEST THIS MRNG BEFORE SLIDING BACK INTO THE LOWER TO MIDDLE 20S. WEAK LAYER Q-VECTOR CONVERGENCE AXIS SLIDES THROUGH SRN WI FROM LATE MRNG INTO THE EARLY EVENING...WITH INCREASING MID-LEVEL RH. THIS TEAMS UP WITH SOME 850-700MB FN VECTOR RESPONSE TO FULL WIND FRONTOGENESIS TO ADD SOME ENHANCED SYNOPTIC SCALE LIFT. THIS MAY BE ENOUGH LIFT TO BREAK THROUGH THE ELEVATED CAP AND PRODUCE ISOLD TO SCT CONVECTION FROM LATE MRNG INTO THE EARLY EVE. BEST CHANCES WILL BE IN THE NORTH...CLOSER TO RIGHT ENTRANCE REGION OF UPPER LEVEL JET. SYNOPTIC SCALE FORCING SLIDES SOUTH OVERNIGHT...SO WL CONFINE SMALL CONVECTION THREAT IN SOUTH TO EVENING. .SUNDAY THROUGH FRIDAY...FORECAST CONFIDENCE...MEDIUM SURFACE HIGH PRESSURE AND NORTHWEST FLOW TO BRING A NEEDED BREAK TO THE HEAT FOR THE FIRST HALF OF NEXT WEEK. HIGHS ARE EXPECTED TO BE IN THE 80S AWAY FROM LAKE MICHIGAN...WITH ONSHORE WINDS LIKELY HOLDING HIGHS IN THE 70S NEAR THE LAKE MOST DAYS. THOUGH MUCH NICER TEMPS EXPECTED...NOT A GREAT SETUP FOR RAIN CHANCES. MODELS NOT SHOWING A CONSISTENT SUBSTANTIAL WAVE IN THE FLOW...SO KEPT DRY FORECAST GOING. UPPER RIDGING TO EVENTUALLY BUILD IN FROM THE WEST BY LATE IN THE WEEK...WITH TEMPS WARMING UP A BIT...POSSIBLY BACK TOWARD THE 90S BY NEXT WEEKEND. && .AVIATION/12Z TAFS/...WL NEED TO WATCH FOR ISOLD TO SCT CONVECTION LATER THIS MRNG AND AFTN AS MID LEVEL FORCING SLIDES SOUTHWARD ACROSS SRN WI. BRIEF MVFR CIGS AND GUSTY WINDS WL ACCOMPANY ANY CONVECTION. CONVECTION THREAT ENDS OVERNIGHT AND SHIFTS SWD. SEVERAL HOURS OF MVFR CIGS ALSO POSSIBLE THIS AFTN AND EVE DUE TO LOW LEVEL COLD AIR ADVECTION...BUT TOO MUCH UNCERTAINTY AT THIS POINT TO PUT INTO TAFS. && .MARINE...FAVORING SHORT TERM NAM GUIDANCE WITH STRONGER LOW LEVEL WINDS. NORTHERN LAKE MI BUOY GUSTING OVER 20KTS SINCE 04Z. LOW LEVEL COLD AIR ADVECTION EXPECTED TO SAG SOUTHWARD OVER SOUTHERN LAKE MI THIS MRNG AND EARLY AFTN...CREATING STEEP LOW LEVEL LAPSE RATES. LATEST MODIS IMAGERY FROM 03Z/07 HAD MID-LAKE TEMPS IN THE MID TO UPPER 70S OVER SRN LAKE MI AND AROUND 70 FARTHER NORTH. WITH TIGHTENING PRESSURE GRADIENT...EXPECT WIND GUSTS TO REACH 25KTS AT TIMES BEGINNING LATER THIS MRNG. HENCE WL BE ISSUING SMALL CRAFT ADVY WITH STAGGERED START TIMES...BEGINNING MID-MRNG IN THE NORTH AND LATE MRNG/EARLY AFTN IN THE SOUTH. BREEZY NORTHEAST WINDS WL CONTINUE ON SUN...BUT THINKING WINDS AND WAVES WL HOLD BELOW ADVY LEVELS FOR NOW. BETTER CHANCE FOR ISOLD TO SCT CONVECTION LATER THIS MRNG AND AFTN. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR WIZ062- 063-067>069. EXCESSIVE HEAT WARNING UNTIL 7 AM CDT THIS MORNING FOR WIZ046- 047-051-052-056>060-066. EXCESSIVE HEAT WARNING UNTIL 2 PM CDT THIS AFTERNOON FOR WIZ064- 065-070>072. LM...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 AM CDT SUNDAY FOR LMZ645-646. SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 7 AM CDT SUNDAY FOR LMZ643-644. && $$ TODAY/TONIGHT AND AVIATION/MARINE...MBK SUNDAY THROUGH FRIDAY...DDV ______________________________________________________________________ KMKX - Reference: ['modis imagery showed lake surface temps in the low 70s...off', '60s in the modis sst pass from 0709z/sun. would think areas of'] 898 FXUS63 KMKX 270237 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 937 PM CDT SUN AUG 26 2012 .UPDATE...PUSH OF DRIER AIR AND SUBSIDENCE BEHIND DEPARTING WAVE RESULTING IN THINNING LOW-MID CLOUDS ACROSS SOUTHERN WI. UPSTREAM SURFACE DEWPOINTS NOT CHANGING MUCH BEHIND WEAK SURFACE FRONT...WHICH IS TO BE EXPECTED AT THIS TIME OF DAY. HOWEVER STILL EXPECT INCREASING BOUNDARY LAYER MIXING FROM JUST OFF THE SURFACE OVERNIGHT BEHIND FRONTAL BOUNDARY. QUITE A BIT OF DRIER AIR AVAILABLE TO MIX DOWN...HENCE WL HOLD OFF ON DENSE FOG ADVY AND KEEP MENTION OF DENSE FOG MORE PATCHY ACROSS SOUTHERN WI. HOWEVER ENOUGH CONCERN FOR DENSE FOG TO ISSUE SPS. ALSO THINKING BOUNDARY LAYER MIXING OF DRIER AIR WILL PRECLUDE REDEVELOPMENT OF LOW STRATUS WITH FOG THE MAIN THREAT. && .AVIATION/06Z TAFS/...WITH LIGHT WINDS AND CLEARING SKIES...WL BRING VSBY IN TAF SITES CLOSE TO ALTERNATE LANDING MINIMUMS IN EXPECTED FOG LATER TONIGHT. MAY EVEN TAKE VSBYS DOWN TO AIRFIELD LANDING MINIMUMS AT KENW FOR SEVERAL HOURS. && .MARINE...SHEBOYGAN WEBCAMS SHOWED AREAS OF DENSE FOG HAD DEVELOPED OVER THE NEARSHORE WATERS. INTERESTING SINCE RECENT MODIS IMAGERY SHOWED LAKE SURFACE TEMPS IN THE LOW 70S...OFF SHORE. PERHAPS THE RECENT SOUTH WINDS RESULTED IN SOME UPWELLING OF COOLER WATERS CLOSE TO SHORE. THERE WERE A FEW PIXELS OF LOW 60S IN THE MODIS SST PASS FROM 0709Z/SUN. WOULD THINK AREAS OF DENSE FOG WOULD CONTINUE UNTIL WINDS TURN MORE OFFSHORE DURING THE NIGHT...WITH WINDS MOSTLY 5 TO 10 KNOTS. FOR THIS REASON...HELD OFF ON MARINE DENSE FOG ADVY FOR NOW. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ MBK ______________________________________________________________________ KMKX - Reference: ['seen from modis 8-day sst...didn\\t go that high in the far east. '] 399 FXUS63 KMKX 291634 AAA AFDMKX AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 1134 AM CDT WED AUG 29 2012 .UPDATE... A FEW CHANGES WERE MADE IN THIS UPDATE...MAINLY TO HIGH TEMPS AND SKY COVER. OVERALL...A BENIGN WX DAY IS ANTICIPATED WITH SFC HIGH OVER MICHIGAN AND MID-LEVEL RIDGING OCCURRING TODAY. SKY COVER WAS DECREASED A BIT OVER THE COURSE OF THE DAY...AND ADJUSTED FOR DIURNAL CU POTENTIAL. CURRENTLY...SCATTERED ALTOCU ARE OBSERVED ON VIS SAT AT AROUND 80-100 HFT ACROSS PORTIONS OF THE CWA. MID-LEVEL CLOUDS ARE EXPECTED TO LINGER GIVEN SOUNDINGS AND WEAK WAA. EXPECT PARTLY TO MOSTLY SUNNY SKIES GIVEN THIS AND DEVELOPMENT OF A FEW DIURNAL CU. HIGHS WERE ADJUSTED AS WELL DUE TO RECENT CHANGES IN SKY AND 925 HPA TEMPS. 925 HPA TEMPS RANGED GENERALLY FROM 26 C FAR WEST TO 22 C FAR EAST...WHICH CORRESPOND TO 90 F TO 84 F. ALTHOUGH WE WILL HAVE ADEQUATE MIXING UP TO AT LEAST 900 HPA GIVEN SOUNDINGS...THERE WILL BE AN ON-SHORE FLOW. AS SUCH...WITH LAKE TEMPS IN THE LOW 70S AS SEEN FROM MODIS 8-DAY SST...DIDN\T GO THAT HIGH IN THE FAR EAST. TEMPS OVER CENTRAL CWA WERE RAISED THOUGH...2-4 DEGREES F. && .AVIATION/18Z TAFS/... EXPECTING VFR CONDITIONS TO CONTINUE FOR THE PERIOD. SCATTERED CLOUD COVER EXPECTED THIS AFTERNOON WITH WEAK WARM AIR ADVECTION. THEN...MID LEVEL RIDGING AND DRY AIR WILL KEEP SKIES MAINLY CLEAR FOR THE REST OF THE PERIOD. WINDS WILL BE A BIT HIGHER OVERNIGHT AS THE PRESSURE GRADIENT INCREASES...PREVENTING FOG FORMATION. LOW LEVEL WIND SHEAR IS POSSIBLE AT MSN TONIGHT AS THE LOW LEVEL JET FORMS. HOWEVER...THE SHEAR WOULD BE MARGINAL...AS THE NAM IS SHOWING CLOSE TO OR JUST UNDER 30 KTS OF WIND DIFFERENCE AND ABOUT A 20 DEGREE DIRECTION CHANGE. BREEZY SOUTHWEST WINDS ARE EXPECTED THURSDAY...WITH GUSTS UP TO 20 TO 25 KTS. && .PREV DISCUSSION... /ISSUED 337 AM CDT WED AUG 29 2012/ TODAY...FORECAST CONFIDENCE - MEDIUM WARM AIR ADVECTION FOCUS EXPECTED TO REMAIN JUST WEST OF CWA EARLY THIS MRNG. LOW LEVELS...BELOW 10K FEET EXPECTED TO REMAIN DRIER. ALSO...CONDENSATION PRESSURE DEFICITS ON 310 THETA SURFACE REMAIN OVER 200MB OVER WESTERN CWA THIS MRNG WITH PREDOMINANTLY NORTHWEST FLOW. PREDOMINANCE OF MESO-SCALE MODELS KEEP ANY ACTIVITY WEST OF CWA. NOT IMPOSSIBLE AN ISOLD -SHRA COULD SNEAK INTO FAR WEST...BUT WL ROLL DICE AND REMOVE SMALL POPS IN WEST. OTHERWISE EXPECT PATCHY MID-LEVEL CLOUDS FROM WEAK WARM AIR ADVECTION TO PUSH SOUTH OF AREA LATER TODAY. BUILDING MID-LEVEL RIDGING AND SUBSIDENCE SHOULD RESULT IN MORE SUNSHINE THIS AFTERNOON...AND TEMPS WARMER THAN TUESDAY. FEW WESTERN LOCATIONS MAY CLIMB TO NEAR 90F. TONIGHT...FORECAST CONFIDENCE - HIGH. RIDGING CONTINUES TO EXPAND OVER SOUTHERN WI TONIGHT AS REMNANTS OF ISAAC PUSHES SLOWLY NORTHWARD INTO THE LOWER MS VALLEY. TIGHTENING GRADIENT WL RESULT IN MORE BOUNDARY LAYER MIXING AND TEMPERATURES REMAINING MILD WITH LESS THREAT FOR FOG. THURSDAY - CONFIDENCE...MEDIUM BROAD 591-594DM UPPER RIDGE WITH WARM SOUTHWEST 850/925 WINDS. 850 TEMPS 23-24C. TAKING ECMWF AS COMPROMISE ON 925 THERMAL FIELD YIELDS 26C IN THE FAR SE TO NEAR 29C IN THE FAR NW CWA. SOUNDINGS ARE QUITE DRY AND BREEZY CONDITIONS EXPECTED WITH ADEQUATE MIXING. TEMPS SHOULD REACH WELL INTO THE 90S. IN SOME CASES THE GFS MOS DEW POINTS ARE 20 DEGREES WARMER THAN THE NAM MOS. GIVEN THE PARCHED LOOK TO THE SOUNDINGS WILL CERTAINLY LEAN TOWARDS THE DRIER LOOK OF THE NAM. FRIDAY - CONFIDENCE...MEDIUM UPPER RIDGE CONTINUES TO DOMINATE. 925 THERMAL FIELD SUPPRESSES HIGHEST TEMPS INTO THE SOUTHWEST CWA WITH A MIN IN THE NE CWA...THANKS TO A WEAK FRONT DROPPING IN FROM THE NORTH. STILL VERY TOASTY WITH 90 PLUS INLAND TEMPS EXPECTED. SATURDAY AND SUNDAY - CONFIDENCE...LOW TO MEDIUM EYES WILL BE ON THE TRACK AND SUBSEQUENT NORTHWARD EXTENSION OF PRECIP ASSOCIATED WITH REMNANTS OF ISAAC. 00Z GEM AND 00Z GFS KEEP IT SOUTH. 12Z ECMWF WAS PRETTY AGGRESSIVE WITH THE MOISTURE PUSH INTO SRN WI SATURDAY NIGHT/SUNDAY. THE 00Z RUN HAS TRENDED TOWARDS THE SOUTHERN SOLUTION WHICH KEEPS MOST IF NOT ALL OF THE PRECIP OUT OF SOUTHERN WI. BLENDED POPS TO MESH WITH DVN AND LOT. IF MODELS MAINTAIN CONSISTENCY IN THIS SOUTHERN SOLUTION LATER FORECASTS MAY BE ABLE TO GO DRY. MONDAY AND TUESDAY - CONFIDENCE...LOW TO MEDIUM UPPER FLOW BECOMES MORE WEST/EAST WITH SOME SHORTWAVE ACTIVITY AROUND MONDAY. APPEARS UPPER FLOW MAY GO ANTICYCLONIC TUESDAY WITH A SURFACE HIGH IN THE MIX TOO...SO A TREND TOWARDS DRY FOR TUESDAY APPEARS PLAUSIBLE. WILL RIDE WITH THE ALLBLEND POPS. AVIATION/12Z TAFS/...CAN NOT RULE OUT A BRIEF FOG PERIOD AT KENW AND KUES EARLY THIS MRNG DUE TO LOW DEWPOINT DEPRESSIONS AND LIGHT WINDS BELOW INVERSION. ANY FOG SHOULD THIN QUICKLY AFTER 12Z. OTHERWISE...A VFR PERIOD EXPECTED FOR THIS TAF ISSUANCE. PATCHY MID-LEVEL CLOUDS THIS MRNG FROM WEAK UPSTREAM WARM AIR ADVECTION SHOULD THIN AS WARM AIR ADVECTION WEAKENS. INCREASING BOUNDARY LAYER WINDS SHOULD PRECLUDE ANY SIGNIFICANT FOG DEVELOPMENT TONIGHT. MARINE...TIGHTENING PRESSURE GRADIENT EXPECTED TO DEVELOP OVER SOUTHERN LAKE MICHIGAN LATER TONIGHT AND THURSDAY DUE TO HIGH PRESSURE LINGERING OVER THE OHIO VALLEY AND SOUTHERN GREAT LAKES AND COLD FRONT MOVING THROUGH THE NORTHERN PLAINS. STRONG LOW LEVEL MIXING OVER INLAND AREAS WILL LIKELY RESULT IN WIND GUSTS REACHING SMALL CRAFT ADVISORY LEVELS DURING THE DAY THURSDAY...HOWEVER STILL SOME SHORT TERM MODELS DIFFERENCES BETWEEN NAM AND GFS PERTAINING TO STRENGTH OF PRESSURE GRADIENT. HENCE PER COORD WITH GRB...WL LET NEXT SHIFT TAKE ONE MORE LOOK AT EXPECTED WIND GUSTS ON THURSDAY BEFORE PULLING TRIGGER ON SMALL CRAFT ADVY. FIRE WEATHER...WEATHER CRITERIA FOR DETERMINING CRITICAL FIRE WEATHER CONDITIONS EXPECTED TO BE REACHED ON THURSDAY WITH SUSTAINED WINDS EXPECTED TO REACH 15 MPH OR HIGHER. AFTERNOON RH WILL DROP TO AROUND 25 PERCENT OR LOWER AND TEMPS WILL BE WELL INTO THE 90S. HOWEVER CFFDRS BUILD-UP INDEX REMAINS WELL BELOW 100 WHICH IS THE THRESHOLD FOR CRITICALLY DRY FUELS AFTER GREEN-UP. WI-DNR WILL BE REASSESSING FUEL MOISTURE THIS MRNG FOR POSSIBLE FIRE WEATHER WATCH INTO PORTIONS OF SOUTHERN WI FOR THU. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...ET/MEB TODAY/TONIGHT AND AVIATION/MARINE...MBK THURSDAY THROUGH TUESDAY...COLLAR ______________________________________________________________________ KMKX - Reference: ['nearshore waters. latest modis imagery shows water temps have '] 208 FXUS63 KMKX 310839 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 339 AM CDT FRI AUG 31 2012 .TODAY AND TONIGHT...FORECAST CONFIDENCE..MEDIUM WEAK UPSTREAM PRESSURE RISES AND SOUTHEAST CANADIAN LOW PRESSURE WILL CONTINUE TO DRAG WEAK COOL FRONT ACROSS SOUTHERN WI TODAY. LOW TO MID LEVEL MOISTURE REMAINS LIMITED AND LINGERING WARM AIR IN THE MID LEVELS WL ACT AS CAP PREVENTING ISOLD PRECIP. HENCE WL CONTINUE DRY FORECAST FOR TODAY. TEMPS TRICKY AS HAVE TO ACCOUNT FOR RAPID COOLING IN EAST AS WINDS SHIFT TO THE NORTHEAST. UPWELLING OF COOLER WATERS OVER THE NEARSHORE AREAS ON THURSDAY WL CONTRIBUTE TO SIGNIFICANT TEMP DROP ALONG SHORE AREAS THIS AFTN. TEMPS MAY FALL 20-30F IN SEVERAL HOURS FROM MILWAUKEE SOUTH. LARGE GRADIENT OF MAX TEMPS EXPECTED ACROSS CWA TODAY...FROM THE LOWER 80S FAR NORTHEAST TO THE LOW TO MID 90S IN THE SOUTH. FRONT SAGS JUST SOUTH OF WI/IL BORDER TONIGHT...WITH MID-LEVEL MOISTURE LINGERING IN SOUTHERN CWA. WEAK ISENTROPIC UPGLIDE OVER BAROCLINIC ZONE AHEAD OF ISAAC REMNANTS MAY BRING SOME MID-LEVEL CLOUDS TO THE AREA LATER TONIGHT. ..SATURDAY AND SUNDAY....FORECAST CONFIDENCE...MEDIUM DID NOT MAKE MUCH OF A CHANGE TO THE FORECAST FOR THE WEEKEND. STILL EXPECTING REMNANTS OF HURRICANE ISAAC TO MOVE THROUGH THE REGION...WITH MOST OF THE RAINFALL STAYING TO THE SOUTH OF WISCONSIN. KEPT SOME LOW POPS TOWARD THE ILLINOIS BORDER...AS NOT OUT OF THE QUESTION THAT SOME RAIN MAY SNEAK NORTH INTO THE STATE. EXPECTING SUNSHINE AT TIMES SAT AND SUN...SO KEPT HIGHS JUST A BIT ABOVE NORMAL AWAY FROM LAKE MICHIGAN...WITH NEAR NORMAL TEMPS NEAR THE LAKE UNDER EASTERLY WINDS. .MONDAY AND TUESDAY...FORECAST CONFIDENCE...MEDIUM WEAK FRONT EXPECTED TO SLIDE THROUGH MONDAY. MOISTURE/LIFT FIELDS NOT VERY IMPRESSIVE...SO KEPT POPS ON THE LOW SIDE. 925 MB TEMPS EVEN WARMER MONDAY...SO ABOVE NORMAL TEMPS TO CONTINUE. LOOKS MAINLY DRY TUESDAY AS HIGH PRESSURE BRIEFLY MOVES THROUGH. MODELS DO TRY AND BRING SOME SHOWERS/STORMS IN FROM THE WEST LATER IN THE DAY AS A WEAK WAVE APPROACHES...SO THREW SOME LOW POPS INTO THE WESTERN FORECAST AREA. NO BIG PUSH OF DRIER AIR BEHIND MONDAY FRONT...SO KEPT 80S GOING FOR TUESDAY. .WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...MEDIUM KEPT POPS GOING FOR WED AND THU...AS A PAIR OF SYSTEMS MOVE THROUGH THE AREA. NEITHER SYSTEM LOOKS PROMISING FOR A SIGNIFICANT AMOUNT OF RAINFALL...BUT STRONGER LOW AND COLD FRONT THURSDAY AT LEAST SUGGESTING SOME COOLER AIR MIGHT FINALLY PUSH INTO THE AREA BY NEXT WEEKEND. && .AVIATION/12Z TAFS/...EARLY MORNING LOW LEVEL WIND SHEAR WILL DIMINISH AS LOW LEVEL JET MOVES OFF TO THE EAST AND WEAKENS OVER SRN WI. SFC WINDS WL ALSO INCREASE WITH INSOLATION THIS MRNG BEFORE PRESSURE GRADIENT WEAKENS AS SFC FRONT SLIDES THROUGH SRN WI. PRESSURE GRADIENT WL REMAIN TIGHTEST OVER KENW...RESULTING IN GUSTY WINDS INTO THE EARLY AFTN. RAPID WIND SHIFT TO THE NNE ALONG WITH GUSTY WINDS CAN BE EXPECTED AT KMKE AND KENW BETWEEN 17Z AND 20Z AS FRONTAL BOUNDARY SLIDES SOUTHWARD. LOW LEVEL MOISTURE REMAINS LIMITED AS FRONT SLIPS THROUGH WITH CAPPING INVERSION. HENCE HELD OFF ON ANY ISOLD PRECIP. INCREASING MID-LEVEL MOISTURE FROM ISAAC REMNANTS APPROACHING SLOWLY FROM THE SOUTH MAY BRING SOME MID-LEVEL CLOUDS TO THE AREA TONIGHT. VFR CONDITIONS EXPECTED FOR THIS TAF PERIOD. && .MARINE...LINGERING PRESSURE GRADIENT OVER SOUTHERN WI AHEAD OF COLD FRONT MAY RESULT IN WIND GUSTS BRIEFLY REACHING SMALL CRAFT ADVY LEVELS OVER SHORE AREAS FROM WIND POINT TO WINTHROP HARBOR FOR 1-3 HOURS LATER THIS MRNG AND EARLY AFTN. HOWEVER DUE TO UNCERTAINTY AND EXPECTED BRIEF PERIOD...WL HOLD OFF ON SMALL CRAFT ADVY FOR LMZ646 AT THIS TIME. COLD FRONT WL RESULT IN WINDS RAPIDLY TURNING TO THE NE LATER TODAY. TIME FRAME FOR WIND SHIFT FROM SGNW3 TO PWAW3 BETWEEN 15Z AND 18Z...AND MLWW3 TO KNSW3 FROM 18Z TO 21Z. GUSTY SOUTHWEST WINDS ON THURSDAY RESULTED IN UPWELLING EVENT OVER NEARSHORE WATERS. LATEST MODIS IMAGERY SHOWS WATER TEMPS HAVE COOLED INTO THE 50S FROM SHEBOYGAN SOUTH TO MILWAUKEE. AS WINDS TURN TO THE NORTHEAST...THESE COOL WATER TEMPS SHOULD MODIFY SOMEWHAT...BUT WL BE INTERESTING TO WATCH HOW FAR LAKESHORE TEMPS DROP IN A SHORT PERIOD OF TIME AFTER THE WIND SHIFT. UPSTREAM DEWPTS IN THE LOW TO MID 60S COULD PRODUCE SOME HAZE OR LIGHT FOG AS IT CROSSES COOLER UPWELLING WATERS AS WELL...BUT TOO MUCH UNCERTAINTY TO INCLUDE IN FORECAST AT THIS POINT. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...MBK SATURDAY THROUGH THURSDAY...DDV ______________________________________________________________________ KMKX - Reference: ['saturday. latest modis imagery shows lake surface temperature in '] 954 FXUS63 KMKX 070830 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 330 AM CDT FRI SEP 7 2012 .TODAY AND TONIGHT...FORECAST CONFIDENCE - MEDIUM. VIGOROUS MID LEVEL SHORT WAVE WILL TEAM WITH INCREASING BAROCLINICITY ACROSS SOUTHERN WISCONSIN TO BRING NMRS SHRA TO THE AREA TODAY INTO EARLY THIS EVENING. IMPRESSIVE LAYER Q-VECTOR CONVERGENCE REACHING 30 UNITS SPREADS INTO SOUTHERN WI THIS MRNG AND EARLY AFTERNOON BEFORE EXITING THE EAST THIS EVENING. LAYER FN VECTOR RESPONSE TO 2D FULL WIND FRONTOGENESIS ALSO SPREADS ACROSS SOUTHERN WI DURING THIS TIME AS WELL. IN ADDITION...STRONG ISENTROPIC OMEGA ON 305 THETA SFC SPREADS ACROSS SRN WI LATER THIS MRNG THRU MID-AFTN. SRN WI WL REMAIN ON NRN FRINGE OF PIVOTING AND WEAKENING LOW LEVEL JET FOCUSING CONVECTION OVER IA ATTM. SCT -SHRA AND ISOLD T FROM THIS FORCING EXPD EARLY THIS MRNG. SHRA ALREADY BEGINNING TO INCREASE TO THE NORTH AROUND KRST AND KONA IN RESPONSE TO INCREASING FRONTOGENESIS. THINKING MORE SCT -SHRA EARLY THIS MRNG WL BECOME MORE NUMEROUS DURING THE MRNG AND AFTERNOON...AND THEN DIMINISH FROM WEST TO EAST DURING THE AFTN INTO THE EARLY EVE. WILL HAVE TO WATCH CLOUDS TONIGHT AS THEY MAY HANG ON A BIT LONGER DUE TO BUILDING THICKNESS TROUGH INTO SOUTHERN WI...ESPECIALLY IN THE EAST. WILL CARRY T MENTION IN SOUTH DUE TO LINGERING ELEVATED WEAK INSTABILITY INTO THE AFTN. SATURDAY AND SATURDAY NIGHT - CONFIDENCE...MEDIUM MAIN FOCUS WILL BE ON SHORTWAVE DROPPING SOUTHEAST ON WESTERN SIDE OF ADVANCING UPPER TROUGH. WINDOW FOR PRECIP POTENTIAL IS MID AFTERNOON INTO MID EVENING. NAM BUFKIT SOUNDINGS SHOW A FAIRLY DRY AND STABLE SOUNDING WITH THE NAM ITSELF NOT PAINTING ANY QPF. GFS/ECMWF/GEM SHOW LIGHT PRECIP IN THE AFOREMENTIONED WINDOW. WEAK THERMAL RIDGE POKES ACROSS SRN/CNTRL WI BEFORE COLD ADVECTION KICKS IN DURING THE EVENING. SUNDAY - CONFIDENCE...MEDIUM STEADY NNW UPPER FLOW AS TROUGH AXIS PULLS FURTHER AWAY. 850 MILLIBAR RIDGE AXIS SHIFTS INTO IOWA WITH SURFACE HIGH BECOME ESTABLISHED ACROSS WI. 925 TEMPS AVERAGING 12-14C YIELDS HIGHS IN THE UPPER 60S TO LOW 70S. MONDAY AND TUESDAY - CONFIDENCE...MEDIUM BROAD 500 MILLIBAR ANTICYCLONIC FLOW ACROSS THE CWA THIS PERIOD. SURFACE/850 HIGHS TO THE EAST. A WARMER SOUTHERLY REGIME KICKS IN. 925 TEMPS SLOW TO RESPOND MONDAY...BUT A SLIGHT WARMING NOTED. A MORE PRONOUNCED WARMING ON TUESDAY WITH 925 TEMPS BACK TO THE UPPER TEENS TO LOW 20S CELSIUS. WEDNESDAY AND THURSDAY - CONFIDENCE...LOW MAIN QUESTION IS HANDLING POPS WITH MODEL TO MODEL INCONSISTENCIES WITH FRONT. GEMNH AND GFS SUGGEST PRECIP ALONG THE FRONT WHILE 00Z ECMWF FAIRLY CONSISTENT IN KEEPING THINGS DRY. UPPER FLOW BECOMES MORE FAVORABLE FOR RIPPLES TO RIDE ALONG BOUNDARY AND GENERATE SOME PRECIP THOUGH MOISTURE RETURN IS A CONCERN. 12Z ECMWF AND 00Z GFS SUPPORTED DECENT POPS FOR THURSDAY WHILE NEW 00Z ECMWF HAS COME IN A LOT DRIER LOOKING. CONSENSUS WAS REACHED TO TRIM THE POPS DOWN TO SLIGHT CHANCE CATEGORY FOR NOW. && .AVIATION/12Z TAFS/...VFR CONDITIONS THIS MORNING SHOULD YIELD TO PERIOD OF MVFR CIGS ASSOCIATED WITH SHRA THIS AFTN. LOW CLOUDS LIKELY TO STICK AROUND INTO THE EVENING ASSOCIATED WITH LOW LEVEL COLD AIR ADVECTION. DRIER AIR SHOULD HELP TO ERODE LOW CLOUDS LATER IN THE NIGHT OR EARLY SATURDAY. ISOLD T EXPCD WITH STRONG DYNAMICS TODAY. && .MARINE...TIGHTENING PRESSURE GRADIENT ASSOCIATED WITH DEEPENING LOW PRESSURE MOVING ALONG A FRONTAL BOUNDARY TO THE SOUTH OF LAKE MICHIGAN ALONG WITH A STEEPENING LOW LEVEL LAPSE RATE WILL RESULT IN GUSTY NORTH WINDS REACHING SMALL CRAFT ADVISORY LEVELS TONIGHT INTO SATURDAY. LATEST MODIS IMAGERY SHOWS LAKE SURFACE TEMPERATURE IN THE NEARSHORE WATERS 68-70F. STRONG LOW LEVEL COLD AIR ADVECTION IS EXPECTED TO INCREASE THE DELTA-T OVER THE LAKE TO 12-13 DEGREES THIS EVENING WITH CONVECTIVE CLOUD DEPTH INCREASING TO 15 TO 20K. WATERSPOUT INDEX INCREASES TO 8 TO 10 UNITS. WL ADD MENTION OF WATERSPOUTS TO HWO FOR LATE AFTERNOON INTO THE EVENING. SCATTERED SHRA THIS MORNING GIVING WAY TO OCNL SHRA THIS AFTN AND EARLY EVE. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 4 PM CDT SATURDAY FOR LMZ643>646. && $$ TODAY/TONIGHT AND AVIATION/MARINE...MBK SATURDAY THROUGH THURSDAY...COLLAR ______________________________________________________________________ KMKX - Reference: ['lake surface. modis imagery shows the lake temp in the near shore'] 821 FXUS63 KMKX 110356 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 1056 PM CDT MON SEP 10 2012 .UPDATE...FEW IF ANY CHANGES NEEDED. OVERNIGHT LOWS LOOK IN GOOD SHAPE WITH LOW LEVEL MIXING PREVENTING SIGNIFICANT COOLING. WEAK UPSTREAM MID-LEVEL WARM AIR ADVECTION CAUSING FEW PASSING CS. && .AVIATION/06Z TAFS/...MINOR LLWS EVENT WITH LOW LEVEL WINDS REACHING 35 KTS BELOW 2K FEET. OTHERWISE A VFR PERIOD WITH GUSTY WINDS ON TUESDAY. POSSIBLY STRONGER LLWS EVENT TUESDAY NIGHT AS LOW LEVEL JET PIVOTS AND WEAKENS ACROSS SOUTHERN WI. && .MARINE...TIGHTENING PRESSURE GRADIENT AND LOW LEVEL MIXING ENCROACHING ON THE VERY LOW LEVELS TO RESULT IN GUSTY WINDS PERSISTING THROUGH THE NIGHT ACROSS NORTHERN MARINE ZONES. OCCASIONAL GUSTS TO 25 KNOTS EXPECTED AT THE SHORE...MORE FREQUENT AWAY FROM THE SHORE DUE TO THE LOW LEVEL UNSTABLE AIR OVER THE LAKE SURFACE. MODIS IMAGERY SHOWS THE LAKE TEMP IN THE NEAR SHORE WATERS AROUND 20C. HENCE PUSHED UP START TIME OF SMALL CRAFT ADVISORY ACROSS NORTHERN TWO ZONES TO PRESENT TIME...AND ALSO EXPANDED ADVISORY TO INCLUDE WIND POINT TO WINTHROP HARBOR ZONE WHICH BEGINS TUESDAY MORNING. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 9 AM TUESDAY TO 9 AM CDT WEDNESDAY FOR LMZ645-646. SMALL CRAFT ADVISORY UNTIL 9 AM CDT WEDNESDAY FOR LMZ643-644. && $$ MBK ______________________________________________________________________ KMKX - Reference: ['with parched air mass above 700. modis sea surface temp image from '] 683 FXUS63 KMKX 232008 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 310 PM CDT SUN SEP 22 2012 .VERY SHORT TERM...TONIGHT AND MONDAY. LOOKS LIKE ANOTHER CHILLY NIGHT AHEAD...WITH HIGH PRESSURE CENTERED JUST TO THE SOUTH OF WISCONSIN THIS EVENING...SLIDING SLOWLY EASTWARD OVERNIGHT. SKIES WILL BE CLEAR THIS EVENING INTO EARLY TONIGHT...WITH HIGH CLOUDS EXPECTED TO INCREASE LATER TONIGHT FROM THE NORTH. WINDS WILL BE LIGHT FOR THE FIRST PART OF TONIGHT ALSO...THOUGH WINDS ALOFT WILL BEGIN TO PICK UP LATER IN THE NIGHT AS THE HIGH MOVES AWAY. OVERALL...LOOKS LIKE ENOUGH TIME FOR TEMPERATURES TO DROP INTO THE MID 30S MOST PLACES BEFORE WINDS/CLOUDS LEVEL THINGS OFF TOWARD MORNING. OPTED TO GO WITH A FROST ADVISORY FOR ALL BUT MILWAUKEE AND OZAUKEE COUNTIES...WHERE IT WILL LIKELY STAY MILDER AGAIN. A NICE DAY EXPECTED TOMORROW...WITH MAINLY SOME HIGH CLOUDS IN THE MORNING. TEMPERATURES WILL WARM UP NICELY UNDER BREEZY SOUTHWEST WINDS...WITH HIGHS EXPECTED TO GET BACK TO NORMAL VALUES FOR EARLY FALL. .SHORT TERM...MONDAY NIGHT THROUGH WEDNESDAY. LOW LEVEL MOISTURE REMAINS VERY LIMITED MONDAY NIGHT AND TUESDAY AS WEAKENING COOL FRONT SLIPS SLOWLY SOUTHWARD ACROSS SOUTHERN WISCONSIN. CONVERGENCE ALONG FRONT REMAINS WEAK SO FRONT IS EXPECTED TO SLIP INTO NORTHERN IL RATHER QUIETLY...WITH A FEW-SCT CU AND WIND SHIFT MARKING ITS PASSAGE. LOW LEVEL WINDS VEER TO THE NORTH TO NORTHWEST TUESDAY NIGHT AND CONTINUE TURNING TO THE NNE ON WED. COLDER AIR FILTERS INTO SOUTHERN WI AND OVER LAKE MI DURING THIS TIME. LOW LEVEL WINDS FLIRT NORTH TO NORTHEAST FOR A TIME ON WED. BOTH ECMWF AND NAM SHOWING INCREASING LOW LEVEL RH BETWEEN 850 AND 700MB WITH PARCHED AIR MASS ABOVE 700. MODIS SEA SURFACE TEMP IMAGE FROM SAT EVE AND BUOY/CMAN OBS HAVE MID-LAKE TEMPS STILL IN THE MID 60S WHILE RECENT OFF SHORE WINDS HAVE COOLED SST INTO THE LOW TO MID 50S. DELTA-T EXPECTED TO INCREASE TO 14-15C ON WED. SOME CONCERN FOR POSSIBLE LAKE EFFECT -SHRA...BUT WITH FLUCTUATING LOW LEVEL WINDS AND QUESTIONABLE AVAILABLE MOISTURE BELOW INVERSION...WL HOLD OFF ON ADDING -SHRA AT THIS TIME. DAYTIME TEMPS WILL COOL 5 TO 12 DEGREES FROM TUESDAY INTO WEDNESDAY AS WINDS TURN NORTHERLY. .LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY. THE EXTENDED PERIOD LOOKS FAIRLY QUIET. STATIONARY BOUNDARY REMAINS WELL SOUTH OF AREA TO START OFF THE PERIOD. GFS HAS BEEN OUTLIER LAST SEVERAL DAYS IN SHOWING STRONGER SHORT WAVE MOVING NORTH OF THIS BOUNDARY INTO WISCONSIN AREA ON THURSDAY AND FRIDAY WHILE ECMWF...GEM AND UKMT CONTINUE TO SHOW WEAKER WAVE MOVING MORE ELY ALONG BAROCLINIC ZONE ACROSS CENTRAL MS VALLEY TOWARD EAST COAST. SINCE LATEST GFS TRENDING FARTHER SOUTH...AND CONCENSUS OF OTHER LONG TERM GUIDANCE...WL CONTINUE DRY FORECAST FOR THU AND REMOVE SMALL POPS FROM IL BORDER AREA THU NGT AND FRI. DRY WEATHER LOOKS TO CONTINUE INTO SATURDAY DUE TO WEAK HIGH PRESSURE RETURNING TO THE WESTERN GREAT LAKES. EXTENDED GUIDANCE BEGINS TO DIVERGE FOR THE LATER HALF OF THE WEEKEND. ECMWF BRINGS WEAKENING SHORT WAVE ACROSS THE NORTHERN PLAINS AND THRU SRN WI SAT NGT INTO SUN AND PHASES IT WITH SRN STREAM SHORT WAVE. ACTUALLY PREFER GFS SOLUTION WHICH HAS SLOWER PROGRESSION OF UPSTREAM SYSTEMS. HPC ALSO LEANING ON GFS AND ECMWF BLEND PRODUCING THEIR BLENDED FIELDS VALID AT 12Z/30. HENCE WL CONTINUE DRY FORECAST FOR DAY 7. SUNSHINE BUT WITH NORTHEAST LOW LEVEL FLOW SHOULD RESULT IN SEASONAL CONDITIONS THROUGH THE PERIOD. && .AVIATION /00Z TAFS/... VFR CONDITIONS EXPECTED TO CONTINUE THROUGH MONDAY. A SMALL CHANCE FOR SOME LOW LEVEL WIND SHEAR LATER TONIGHT...BUT GENERALLY APPEARS THAT WINDS ALOFT WILL ONLY INCREASE TO HIGH ENOUGH VALUES BY MORNING...WHEN WINDS AT THE SURFACE WILL START COMING UP ALSO. UNLESS SOMETHING CHANGES...LOOKS FAR TOO MARGINAL AND FOR TOO SHORT OF A TIME TO PUT IN TAFS. && .MARINE... STRONG SOUTHWEST WINDS EXPECTED TOMORROW AS PRESSURE GRADIENT WILL TIGHTEN ACROSS THE GREAT LAKES. WILL SEE GUSTS OF 25 OR 30 KNOTS FROM MID-LATE MORNING AND INTO THE NIGHT. HIGHEST GUSTS WILL BE IN THE AFTERNOON TOWARD SHEBOYGAN...POSSIBLY FLIRTING WITH GALE WARNING CRITERIA FOR A TIME. SEEMED TOO BORDERLINE FOR A WARNING...SO OPTED FOR A SMALL CRAFT ADVISORY FOR ALL MARINE ZONES FROM 14Z SAT MORNING...TO 09Z SAT NIGHT. WAVES WILL NOT GET OUT OF HAND DUE TO OFFSHORE NATURE OF WINDS...PEAKING AT 3 TO 5 FEET IN THE NORTHERN ZONES...WITH THE HIGHEST WAVES TOWARD OPEN WATERS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...FROST ADVISORY FROM 1 AM TO 7 AM CDT MONDAY FOR WIZ046-047-051-052-056>059-062>065-067>072. LM...SMALL CRAFT ADVISORY FROM 9 AM MONDAY TO 4 AM CDT TUESDAY FOR LMZ643>646. && .CONFIDENCE... TONIGHT AND MONDAY...MEDIUM TO HIGH. MONDAY NIGHT THROUGH TUESDAY NIGHT...MEDIUM TO HIGH. WEDNESDAY...MEDIUM. WEDNESDAY NIGHT THROUGH SATURDAY...MEDIUM TO HIGH. SATURDAY NIGHT AND SUNDAY...LOW TO MEDIUM. $$ VERY SHORT TERM/AVIATION/MARINE...DDV SHORT TERM/LONG TERM...MBK ______________________________________________________________________ KMKX - Reference: ['sunday. latest modis images has uniform lake sfc temps around 16c'] 977 FXUS63 KMKX 300306 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 1006 PM CDT SAT SEP 29 2012 .UPDATE...WILL KEEP AN EYE ON OBSERVATIONS...AS MAY NEED TO ADD SOME PATCHY FOG TO EASTERN AREAS. TEMPERATURES HAVE FALLEN RAPIDLY IN EASTERN AREAS WHERE EARLIER INFLUX OF MARINE LAYER HAS PUSHED DEWPOINTS INTO THE 40S. BREEZY BOUNDARY LAYER WINDS SHOULD PREVENT THICKER FOG HOWEVER. STILL EXPECT A PERIOD OF LAKE CLOUDS TO MOVE INLAND LATER TONIGHT AND SUNDAY MORNING AS COLD AIR SETTLES OVER SOUTHERN LAKE MICHIGAN. INCREASING CONVERGENCE AND LINGERING MARINE LAYER MAY ALSO HELP CAUSE SOME STRATUS OVER SOUTHEAST WI FOR A TIME. DRIER AIR SHOULD EVENTUALLY OVERWHELM LAKE MOISTURE ALLOWING MORE SUNSHINE TO RETURN LATER SUNDAY. OVERNIGHT TEMPS MOSTLY IN GOOD SHAPE. WL NEED TO LOWER FEW SPOTS IN THE EAST. && .AVIATION/06Z TAFS/...00Z NAM CONTINUES TO SHOW BRIEF PERIOD OF MOISTURE FLUX CONVERGENCE TIED TO SURGE OF COLD AIR ACROSS LAKE MICHIGAN AND INCREASE IN LOW LEVEL CONVERGENCE AND LOW LEVEL RH LATE TONIGHT AND SUNDAY MORNING. DELTA-T INCREASES TO AROUND 10-11C AT THIS TIME. LAST SEVERAL IR SHOW SOME INCREASE IN LAKE CLOUDS OVER NORTH PART OF LAKE. WL BRING A 1-3 HOUR PERIOD OF BKN MVFR INTO ERN TAF SITES EARLY SUN MRNG. OTHERWISE...EXPC VFR CONDITIONS FOR MOST OF THE PERIOD. INCREASING BOUNDARY LAYER WINDS SHOULD PREVENT SIGNIFICANT FOG OVERNIGHT AS WELL. && .MARINE...NEPHANALYSIS REVEALS LOW LEVEL COLD AIR HAS MOVED OVER NORTHERN LAKE MICHIGAN...AND WILL CONTINUE TO MOVE SOUTHWARD OVERNIGHT AS LOW PRESSURE STRENGTHENS SLIGHTLY OVER THE OHIO VALLEY. STILL EXPECT UNSTABLE CONDITIONS TO FORM OVER THE LAKE WHICH WILL ALLOW STRONGER NORTHEAST WINDS TO MIX TO SURFACE LATER TONIGHT AND SUNDAY. LATEST MODIS IMAGES HAS UNIFORM LAKE SFC TEMPS AROUND 16C FROM THE SHORE OUT TO MID-LAKE. FORECAST SOUNDINGS CONTINUE TO FAVOR WINDS REMAINING MOSTLY BELOW 20 KNOTS...BUT PERSISTENT NORTHEAST FLOW OF COLD AIR WILL CAUSE WAVES TO BUILD TO AROUND 3 FEET OR HIGHER. THE HIGHEST WINDS WILL BE IN THE SOUTHERN ZONES...HENCE SMALL CRAFT ADVISORY REMAINS IN EFFECT. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 1 AM TO 10 PM CDT SUNDAY FOR LMZ645- 646. && $$ MBK ______________________________________________________________________ KMKX - Reference: ['thursday. latest modis imagery and buoy sea surface temperature'] 054 FXUS63 KMKX 220830 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 330 AM CDT MON OCT 22 2012 .TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM. GOES SOUNDER INDICATES PRECIPITABLE WATER VALUES HAVE ALREADY DOUBLED IN LAST 24 HOURS TO AROUND 1 INCH OVER SOUTHERN WI. INCREASING SOUTH WINDS OVER CENTRAL CONUS AHEAD OF LONG WAVE TROUGH AMPLIFICATION OUT WEST CONTINUE TO PULL DEEPER LOW LEVEL MOISTURE NORTHWARD. SURFACE DEWPOINTS HAVE RISEN INTO THE MIDDLE 50S TO AROUND 60 AS CLOSE AS CENTRAL IA...AHEAD OF APPROACHING WEAK SURFACE FRONT. THIS ADDED MOISTURE AND STRENGTHENING LOW LEVEL JET PRODUCING INCREASING CONVECTION OVER SW IA/NRN MO. UPSTREAM MID LEVEL SHORT WAVE CAUGHT IN SOUTHWEST FLOW ALSO CONTRIBUTING LIFT TO CONVECTION. PER IR IMAGERY SHORT WAVE UPSTREAM FROM CONVECTION OVER SOUTHEAST NE AREA. DESPITE WEAKENING OF LOW LEVEL JET TO THE SOUTH OF WI THIS MORNING...WAVE EXPECTED TO CONTINUE NORTHEAST ACROSS SRN WI/NRN IL AREA LATER THIS MRNG AND AFTN. WITH MOISTURE ALREADY IN PLACE...WL CONTINUE CATEGORICAL POPS FROM MID-MRNG THRU THE AFTN. WITH ELEVATED INSTABILITY STILL EXPECTED TO SURGE INTO SRN WI...WL CONTINUE T MENTION. MUCAPES MAY REACH 1000 J IN THE SOUTH. HIGH TEMPERATURES TRICKY TODAY DUE TO THICKENING CLOUDS AND PRECIP...AND COOL NEARSHORE LAKE MI WATERS. SYNOPTIC SCALE LIFT ASSOCIATED WITH WAVE PUSHES OFF TO THE EAST DURING THE LATE AFTN AND EVE. HOWEVER LINGERING FRONTAL BOUNDARY AND LOW LEVEL CONVERGENCE IN THE AREA SHOULD STILL TRIGGER SCT TO NUMEROUS -SHRA FOR A TIME...ALONG WITH PATCHY DRIZZLE LATER IN THE NIGHT. WL CONTINUE SMALL THREAT FOR THUNDER IN SOUTH LATER TNGT AS LOW LEVEL JET GETS REENERGIZED JUST TO THE SOUTH. LIGHT BOUNDARY LAYER WINDS AND DEEP MOISTURE SHOULD RESULT IN FOG AND MAYBE DENSE FOG DURING THE LATE NIGHT. .TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM. NAM/GFS/ECMWF/CANADIAN MODELS SHOW WARM FRONT MOVING NORTH OF THE AREA THROUGH THE DAY TUESDAY. NAM IS SLOWER THAN THE OTHER MODELS IN MOVING THE FRONT TO THE NORTH. NAM FORECAST SOUNDINGS ARE AGAIN SHOWING A LOT OF ELEVATED AND MEAN LAYER CAPE VERSUS THE GFS SOUNDINGS. GIVEN THE STRONG WARM AIR AND MOISTURE ADVECTION INTO THE REGION...WOULD LEAN MORE TOWARD THE LOWER INSTABILITY VALUES OF THE GFS SOUNDINGS...WHICH HAVE A MORE REALISTIC TEMPERATURE STRUCTURE. WILL CONTINUE THE CHANCE POPS FOR TUESDAY...WITHIN WARM AIR/MOISTURE ADVECTION REGIME. WARM TEMPERATURES INTO THE 70S ARE EXPECTED SOUTH OF THE WARM FRONT...WITH SOUTH WINDS. THE WARM FRONT THEN SHIFTS TO THE NORTHWEST AND LINGERS THERE TUESDAY NIGHT INTO WEDNESDAY NIGHT. SOUTH WINDS CONTINUE TO BRING WARM TEMPERATURES INTO THE AREA DURING THIS TIME...WITHIN THE WARM SECTOR AIRMASS. GFS FORECAST SOUNDINGS SHOW CAPPING OF SURFACE BASED AIR PARCELS DURING THIS TIME...WITH NAM SOUNDINGS AGAIN SHOWING A LOT OF MEAN LAYER AND ELEVATED CAPE. LEANED TOWARD THE GFS SOUNDINGS FOR THIS PERIOD AS WELL. WILL TRY TO GO WITH LOWER END POPS FOR THIS PERIOD...AS WARM SECTOR SHOULD BE CAPPED. AN EXCEPTION MAY BE WEDNESDAY AFTERNOON IN NORTHWESTERN SECTIONS OF THE AREA...WHERE THE SOUTHWESTERLY LOW LEVEL JET NOSE FOCUSES...WITH SOME FOCUSED WARM AIR ADVECTION. IT IS ALSO POSSIBLE THAT THE CAP WOULD LEAD TO DRY CONDITIONS ACROSS THE WHOLE AREA AS WELL. ANOTHER WARM DAY FOR WEDNESDAY...WITH 70S FOR HIGHS ONCE AGAIN. MAY SEE ANOTHER ROUND OF FOG...SOME POSSIBLY DENSE...TUESDAY NIGHT WITH WARM AND HUMID AIRMASS IN PLACE. .THURSDAY THROUGH SUNDAY...FORECAST CONFIDENCE IS MEDIUM. GFS/ECMWF AGREE FAIRLY WELL WITH TIMING OF STRONG COLD FRONT THROUGH THE AREA ON THURSDAY. STRONG LOW LEVEL FRONTOGENESIS WITH THE FRONT SHOULD INTERACT WITH THE WARM AND MOIST AIRMASS AHEAD OF IT TO BRING SHOWERS AND THUNDERSTORMS. STRONG TO SEVERE STORMS REMAIN POSSIBLE DURING THIS TIME...AS STRONG DEEP LAYER WIND SHEAR IS IN PLACE. DEGREE OF INSTABILITY IS STILL IN QUESTION...AND WILL DEPEND ON HOW MUCH CLOUD COVER IS ACROSS THE AREA. TIMING OF FRONT DURING THE DAY ALSO HELPS WITH SEVERE CHANCES. WILL CONTINUE TO MENTION POTENTIAL IN HAZARDOUS WEATHER OUTLOOK FOR NOW. TRAILING VORTICITY MAXIMUM SLIDES NORTHEAST THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY...STRONGER ON THE GFS THAN THE ECMWF. THE GFS CONTINUES TO SHOW QPF WITH THIS FEATURE DURING THIS TIME...WITH THE ECMWF DRY. WILL CONTINUE TO USE CONSENSUS OF MEDIUM RANGE MODEL POPS. STRONG COLD AIR ADVECTION BEHIND THE FRONT THURSDAY NIGHT THROUGH SATURDAY WILL BRING MUCH COLDER TEMPERATURES TO THE AREA. THIS MAY LEAD TO A MIX OF RAIN AND SNOW SHOWERS LATER FRIDAY NIGHT. QUIET WEATHER THEN EXPECTED THROUGH THE REST OF THE WEEKEND. WENT WITH CONSENSUS POPS AND TEMPERATURES DURING THIS TIME. && .AVIATION/12Z TAFS/...EXPECT MVFR CIGS TO ACCOMPANY SHOWERS AND THUNDERSTORMS THAT WILL SWEEP ACROSS TAF SITES LATER THIS MORNING AND AFTERNOON. LIGHTER BOUNDARY LAYER WINDS...MOIST LOW LEVELS AND LINGERING AREAS OF LIGHT PRECIP WILL RESULT IN LOW CIGS OF IFR OR LOWER FOR MOST OF TNGT. DENSE FOG MAY ALSO DEVELOP. && .MARINE...WINDS EXPECTED TO REMAIN LIGHTER THROUGH TUESDAY AS FRONTAL BOUNDARY SETS UP OVER SOUTHERN WI AND LOWER LAKE MI. MAIN PROBLEM WILL BE DENSE FOG THREAT. WARM...MOIST AIR EXPECTED TO SURGE OVER SOUTHERN LAKE LATE TODAY AND TONIGHT AND LINGER INTO THURSDAY. LATEST MODIS IMAGERY AND BUOY SEA SURFACE TEMPERATURE DATA HAS THE LAKE SURFACE TEMPERATURE RANGING FROM THE MIDDLE 50S IN THE MID LAKE TO THE MIDDLE 40S IN PORTIONS OF THE NEAR SHORE SHALLOWER WATERS. DEWPOINTS WL LIKELY RISE INTO THE MIDDLE 50S TO LOWER 60S IN THE NEXT 12-24 HOURS. HENCE THIS MILD MOIST AIR WOULD BE COOLED OVER THE LAKE POSSIBLY RESULTING IN ADVECTION DENSE FOG. SOUTHEAST WINDS WILL LIKELY PULL THE 50-55 DEGREE WATER INTO THE NEARSHORE AREAS...REDUCING THE TEMPERATURE GRADIENT. SO FOR NOW WL MENTION AREAS OF DENSE FOG LATE TNGT BUT HOLD OFF ON ANY ADVY. COOLER NEARSHORE WATERS MAY RESULT IN MORE ELY SFC WINDS FOR A TIME LATER TODAY AND TNGT. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...MBK TUESDAY THROUGH SUNDAY...WOOD ______________________________________________________________________ KMKX - Reference: ['for a time. modis measurement from 16z shows average sea surface '] 030 FXUS63 KMKX 262017 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 315 PM CDT FRI OCT 26 2012 .VERY SHORT TERM...TONIGHT AND SATURDAY. MAIN ISSUE IS PROGRESSION OF AND ANTICIPATED DISSIPATION OF LARGE CLOUD MASS FROM NRN IA THROUGH MN INTO NW WI. THIS CLOUD AREA HAS AN INCREASINGLY DIURNAL LOOK. SO NOT EXPECTING THIS TO LAST LONG OR MAKE MUCH HEADWAY INTO SRN WI. UPPER DISTURBANCE TRACKS SOUTH AND WILL LIKELY SEE SOME OF THE HIGH CLOUDS THAT ARE CRUISING NE FROM KS AND NE. CHILLY NIGHT WITH PLENTY OF INLAND MID 20S WITH L-M30S LAKESIDE/IN THE CITY. VORT TRACKS TO OUR SOUTHEAST AND EAST WITH BROAD 500 MILLIBAR CYCLONIC FLOW LINGERING. A WEAK WAVE OR TWO ENCROACHES ON SRN WI THOUGH AIRMASS PROGGD TO BE QUITE PARCHED WITH SURFACE HIGH PRESSURE IN CONTROL. 925 TEMPS OF AROUND 0C SUGGEST HIGHS OF 43-46. .SHORT TERM...SATURDAY NIGHT THROUGH MONDAY. MAIN CONCERN FOR THIS PERIOD IS SMALL THREAT FOR LIGHT LAKE EFFECT PRECIPITATION LATER SATURDAY NIGHT AND SUNDAY. AS UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE BUILD INTO THE WESTERN GREAT LAKES OVER THE WEEKEND...THE LOW LEVEL WINDS TURN NORTH TO NORTHEAST FOR A TIME. MODIS MEASUREMENT FROM 16Z SHOWS AVERAGE SEA SURFACE TEMPERATURE AROUND 11-12C ACROSS SOUTHERN LAKE MI. HENCE EXPECT DELTA-T TO INCREASE TO AROUND 16C. 1000-850MB FLOW DOES TURN TO THE NORTHEAST FOR A TIME LATER SATURDAY NIGHT INTO SUNDAY. ALL SHORT TERM GUIDANCE DOES SHOW INCREASING LOW LEVEL RH. HOWEVER RH REMAINS SHALLOW AND MOSTLY BELOW 3K. FOR THIS REASON...WL HOLD OFF ON ADDING ANY POPS FOR LIGHT RAIN OR SNOW SHOWERS AT THIS TIME...BUT A BRIEF SPRINKLE OR FLURRY CAN NOT BE RULED OUT...ESPECIALLY SUN MRNG DURING TIME OF BEST LOW LEVEL CONVERGENCE ALONG THE LAKESHORE. FOR NOW WL GO WITH P/CLDY WORDING...BUT A PERIOD OF M/CLDY SKIES POSSIBLE SUN MRNG. OTHERWISE...MAY EXPERIENCE SOME PASSING MID-HIGH LEVEL CLOUDS FROM WEAKENING UPSTREAM SYSTEMS AS THEY BUMP UP INTO INCREASING RIDGING OVER WI AND WESTERN GTLAKES. FOR THIS REASON...KEPT OVERNIGHT LOW TEMPERATURES SLIGHTLY WARMER THAN POTENTIAL FOR FULL NIGHT OF RADIATIONAL COOLING. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY. THE FORECAST ISSUE FOR THIS PERIOD REMAINS THE TRACK OF EXTRA-TROPICAL REMNANTS OF HURRICANE SANDY. DETERMINISTIC ECMWF REMAINS THE OUTLIER WITH A FASTER AND MORE WESTERLY TRACK...PUSHING INTO THE DELMARVA REGION ON MONDAY WHILE THE UKMT...GEMNH AND GFS90 REMAIN FARTHER EAST INITIALLY...WITH THE CENTER PUSHING ASHORE FARTHER NORTH ON TUE. DGEX CLOSER TO ECMWF BUT A LITTLE FARTHER EAST AS WELL. GFS ENSEMBLE SHOWING ALOT OF UNCERTAINTY WITH THE TIMING AND TRACK OF THIS SYSTEM HOWEVER. HPC LEANING MORE ON ECMWF ENSEMBLE MEAN...WHICH TAKES EXTRA-TROPICAL SYSTEM ON FASTER AND FARTHER WEST TRACK TOWARD THE WESTERN GTLAKES LATER TUE AND WED. THIS SOLUTION WOULD RESULT IN MORE NORTH TO NORTHEAST LOW LEVEL FLOW ACROSS LAKE MICHIGAN. 85H TEMPERATURES AT THIS TIME RANGING FROM -2 TO -5C WITH STRONG NORTHERLY FLOW. TIGHTER PRESSURE GRADIENT AS INDICATED BY ECMWF WOULD RESULT IN STRONG LOW LEVEL FLOW AND POSSIBLE LOW LEVEL WINDS FLIRTING WITH NORTHEAST FOR A TIME. WITH DELTA-T RANGING FROM 12 TO 16C DURING THIS TIME...POTENTIAL WOULD EXIST FOR RAIN AND SNOW SHOWERS. MAY CARRY SOME LOW POPS IN THE EAST FOR MOST SUSCEPTIBLE TIME PERIOD FROM TUE INTO WED...BUT CONFIDENCE REMAINS LOW. FARTHER WEST TRACK INDICATED BY ECMWF ENSEMBLE MEAN WOULD ALSO CARRY STRONGER MID-LEVEL SHORT WAVE ACROSS WI DURING THIS PERIOD AS WELL...BUT DUE TO CONSIDERABLE UNCERTAINTY...WL CONTAIN LOW POPS TO EASTERN AREAS FOR NOW. COLD AIR REMAINS OVER WESTERN GREAT LAKES FOR THE BULK OF THE PERIOD KEEPING TEMPERATURES BELOW NORMAL FOR LATE OCTOBER. && .AVIATION /00Z TAFS/...LARGE AREA OF VFR STRATOCUMULUS NOT MAKING MUCH PROGRESS INTO SOUTHERN WI. LOW LEVEL RH PROGS AND BUFKIT SUGGEST IT WILL NOT MAKE IT AS WELL. CIRRUS RIDING NORTHEAST FROM MO/SE IA WITH JET STREAK ROUNDING BROAD CENTRAL PLAINS TROUGH. OVERALL HIGH PRESSURE WILL CONTINUE TO BUILD IN ACROSS THE AREA TONIGHT INTO SATURDAY. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && .CONFIDENCE... TONIGHT AND SATURDAY...MEDIUM. SATURDAY NIGHT AND SUNDAY...LOW TO MEDIUM. MONDAY AND MONDAY NIGHT...MEDIUM. TUESDAY AND WEDNESDAY...LOW TO MEDIUM. THURSDAY AND FRIDAY...MEDIUM. $$ VERY SHORT TERM/AVIATION...PC SHORT TERM/LONG TERM...MBK ______________________________________________________________________ KMKX - Reference: ['the lake with the cold front fri morning. 19z modis sea surface '] 069 FXUS63 KMKX 152053 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 253 PM CST THU NOV 15 2012 .TONIGHT AND FRIDAY...FORECAST CONFIDENCE MEDIUM TO HIGH. A SURFACE TROUGH WILL SAG INTO SOUTHERN WISCONSIN THIS EVENING AND SORT OF WASH OUT. A WEAK COLD FRONT...APPARENT IN THE 925MB TEMPERATURE CONTOURS...WILL DROP SOUTH BEHIND THE TROUGH OVERNIGHT. SOUTH WINDS WILL BECOME LIGHT AND VARIABLE THIS EVENING AND THEN INCREASE A LITTLE OUT OF THE NORTH-NORTHEAST EARLY FRIDAY MORNING WITH THIS FRONT. THE NAM...GFS AND ECMWF ALL ARE CONSISTENT IN BRINGING IN A LOW LEVEL CLOUD DECK TO SOUTHEAST WISCONSIN LATE TONIGHT AND FRIDAY MORNING. THERE IS SOME QUESTION ABOUT WHETHER OR NOT THE MODELS ARE OVERDOING THIS LAYER OF HIGH RELATIVE HUMIDITY BETWEEN THE SURFACE AND 4000 FEET. 850MB AND 925MB TEMPS DROP TO AROUND 0 TO -1C NEAR THE LAKE WITH THE COLD FRONT FRI MORNING. 19Z MODIS SEA SURFACE TEMPERATURE SHOWS TEMPS IN THE UPPER 40S OR 9C. THE LAKE-AIR TEMP DIFFERENCE SHOULD BE ENOUGH TO GENERATE CLOUD COVER...ESPECIALLY IF THERE IS ANY MOISTURE TRAPPED IN THIS LAYER WITHIN THE WEAK BAROCLINIC ZONE DROPPING DOWN. ONE DISCOURAGING FACT FOR THIS QUESTIONABLE MOISTURE IS THE VERY CLEAR SKIES IN MN AND NORTHERN WI THIS AFTERNOON. NONETHELESS...OPTED TO INCREASE CLOUD COVER ACROSS THE WHOLE FORECAST AREA BUT ESPECIALLY NEAR THE LAKE FROM 09Z THROUGH 18Z. FORECAST SOUNDINGS SHOW THIS CLOUD LAYER TO BE ABOUT 2KFT TO 3KFT THICK...SO EXPECT IT TO SCATTER AWAY DURING THE AFTERNOON HOURS WITH MIXING AS THE FRONT GETS INTO NORTHERN IL AND WASHES OUT. CLOUD COVER WILL IMPACT MAX TEMPS FRIDAY...SO KEPT THEM CLOSE TO MOS GUIDANCE IN THE MID 40S NEAR THE LAKE AND UPPER 40S WELL INLAND. SATURDAY AND SUNDAY - CONFIDENCE...MEDIUM TO HIGH HIGH PRESSURE TO THE EAST. BROADLY ANTICYCLONIC SOUTHWEST 500 MILLIBAR FLOW IN PLACE. 925 TEMPS WILL REACH 5-6C SATURDAY AND WARM TO NEAR 8C ON SUNDAY. AIRMASS QUITE DRY. MONDAY - CONFIDENCE...MEDIUM MODELS IN DECENT AGREEMENT BRINGING NEGATIVE TILTED SHORTWAVE INTO THE AREA. QPF LOOKS LIGHT. WILL GO WITH HIGHER END CHANCE POPS FOR NOW. GOOD DEAL OF CLOUD COVER WITH RESULTING TEMPS A BIT COOLER THAN OVER THE WEEKEND. TUESDAY - CONFIDENCE...MEDIUM GFS QUICKER WITH SURFACE TROUGH SHIFTING TO THE EAST OF WI WITH WEST WINDS BRINGING IN DRIER AIR. MEANWHILE ECMWF SHOWS PRECIP TO THE EAST THOUGH LINGERING 925/850 RH DUE TO SLOWER AND WEAKER LOOK TO SURFACE TROUGH. WEDNESDAY - CONFIDENCE...MEDIUM SWIFT WEST/EAST NEARLY ZONAL FLOW FROM THE ECMWF WITH SLIGHTLY MORE OF A RIDGE LOOK TO THE GFS. BEST ENERGY/MOISTURE TO THE NORTH. BOTH GFS AND ECMWF SUGGEST A FROPA THOUGH IT LOOKS DRY AND FAIRLY WEAK. THURSDAY - CONFIDENCE...MEDIUM CONTINUED ZONAL OR SLIGHTLY ANTICYCLONIC FLOW PERSISTS. ANY DISTURBANCES ARE NORTH OR TOO WEAK TO SUPPORT PRECIP ESPECIALLY GIVEN DRY ATMOSPHERE/LACK OF ANY MOISTURE FLUX FROM THE SOUTH. && .AVIATION/00Z TAFS/...SKIES SHOULD BE CLEAR FOR THE FIRST HALF OF THE NIGHT. THEN A WEAK SURFACE TROUGH WILL MOVE THROUGH SOUTHERN WI TONIGHT. A WEAK COLD FRONT WILL ZIP DOWN THE LAKE AND IT IS LOOKING INCREASINGLY LIKELY FOR IFR/FUEL ALTERNATE STRATUS TO DEVELOP LATE TONIGHT AS NORTHEAST WINDS BRING MOISTURE INLAND TO AT LEAST SHEBOYGAN AND WAUKESHA AND SOUTHWARD DOWN THE LAKESHORE...ESPECIALLY BETWEEN 12Z AND 16Z FRIDAY. CEILINGS AT EASTERN TAF SITES SHOULD IMPROVE TO MVFR LATER IN THE MORNING OR EARLY AFTERNOON. CIGS SHOULD SCATTER OUT BY LATE FRI AFTERNOON...AS THE CLOUDS WILL NOT BE VERY THICK. MADISON SHOULD SEE THESE LOW CLOUDS SPREAD INLAND BY MID FRI MORNING AND THEN SCATTER OUT DURING THE AFTERNOON. NOT CONFIDENT ON CEILING HEIGHTS...BUT EXPECTING MVFR RATHER THAN IFR. && .MARINE...WINDS WILL INCREASE OUT OF THE NNE LATE TONIGHT AND FRIDAY MORNING AS A WEAK COLD FRONT DROPS DOWN THE LAKE. MAX WINDS SHOULD BE IN THE 15 TO 20 KNOT RANGE. WAVES EXPECTED TO BUILD UP TO 4 FEET FRIDAY AFTERNOON. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TONIGHT/FRIDAY AND AVIATION/MARINE...MRC FRIDAY NIGHT THROUGH THURSDAY...COLLAR ______________________________________________________________________ KMKX - Reference: ['clouds over srn wi for a time this mrng. timely viirs day/night band '] 910 FXUS63 KMKX 260909 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 309 AM CST MON NOV 26 2012 .TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM TO HIGH WEAK LOW LEVEL COLD AIR ADVECTION EXPECTED TO CAUSE AREAS OF LOWER CLOUDS OVER SRN WI FOR A TIME THIS MRNG. TIMELY VIIRS DAY/NIGHT BAND IMAGE FROM 0721Z SHOWED THICKER CLOUDS OVER NORTHWEST CWA EXTENDING ACROSS CENTRAL INTO NRN WI. A FEW FLURRIES GETTING SHAKEN FROM THESE CLOUDS FARTHER NORTH IN VICINITY OF WEAK LOW LEVEL CONVERGENCE. AS UPPER JET FINALLY SLIDES OFF TO THE EAST...LOW CLOUDS WILL INCREASE FOR A TIME EARLY THIS MRNG ACROSS SRN WI. HOWEVER INCREASING SUBSIDENCE FROM LEFT ENTRANCE REGION AND DRYING SHOULD RESULT IN CLOUDS DECREASING LATER THIS MRNG AND AFTN. DAYTIME TEMPS NOT EXPCD TO RISE MUCH DUE TO NORTHWEST WINDS CARRYING EVEN COLDER AIR OVER THE REGION. NORTHWEST WINDS AND APPROACHING HIGH PRESSURE ALSO PROTECTING SRN WI FROM THE ISENTROPIC LIGHT PRECIP EVENT GOING ON TO THE SOUTHWEST OF WI. DIMINISHING WINDS AND MOSTLY CLEAR SKIES FOR THE BULK OF TNGT WL ALLOW TEMPS TO FALL INTO THE 10 TO 20 RANGE MOST AREAS. FEW LOCATIONS MAY DROP INTO THE SINGLE DIGITS IN THE WEST. .TUESDAY THROUGH THURSDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH HIGH PRESSURE CENTERED TO THE SOUTH OF WISCONSIN WILL KEEP DRY WEATHER GOING ON TUESDAY. WILL START OUT WITH A GOOD AMOUNT OF SUNSHINE...BUT WILL SEE MID AND HIGH LEVEL CLOUDS INCREASE THROUGH THE DAY AHEAD OF AN APPROACHING WEAK SHORTWAVE AND COLD FRONT. WILL SEE MOSTLY CLOUDY SKIES IN THE EVENING...CLEARING BY MORNING AS HIGH PRESSURE APPROACHES FROM THE NORTHWEST. TOOK OUT MENTION OF FLURRIES IN THE NORTHEAST TUESDAY EVENING...AS MODELS NOW FARTHER NORTH WITH BETTER MOISTURE AND FORCING. HIGH PRESSURE WILL THEN BRING MOSTLY SUNNY SKIES ON WEDNESDAY...WITH INCREASING CLOUDS BY THURSDAY AFTERNOON AHEAD OF ANOTHER WEAK WAVE. TEMPERATURES TUESDAY WILL REMAIN A FEW DEGREES BELOW NORMAL. THERE WILL NOT BE MUCH OF A COLD PUNCH WITH THE TUESDAY NIGHT SYSTEM...WITH TEMPERATURES ALOFT RECOVERING QUICKLY ON WEDNESDAY. SHOULD ACTUALLY END UP MILDER WEDNESDAY THAN ON TUESDAY...WITH HIGHS APPROACHING NORMAL VALUES. SHOULD BE EVEN MILDER THURSDAY...WITH HIGH TEMPS A COUPLE DEGREES ABOVE NORMAL. .THURSDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE...LOW TO MEDIUM LESS CONFIDENCE TONIGHT FOR LATE WEEK INTO NEXT WEEKEND THAN THE LAST COUPLE NIGHTS. WARM FRONT WILL SETUP IN THE VICINITY OF THE FORECAST AREA THURSDAY NIGHT...WITH MODEL DIFFERENCES AS TO EXACT PLACEMENT AND RESULTANT TEMPERATURES. ADDITIONALLY...THE GFS MAINTAINS A SHORTWAVE BRINGING RAIN/SNOW CHANCES THURSDAY NIGHT INTO FRIDAY...WHILE THE CANADIAN REMAINS DRY AND THE ECMWF HAS BACKED OFF PRECIP CHANCES. DID KEEP SOME LOW POPS PER THE CONSISTENT GFS SOLUTION. TEMPS ALOFT FRIDAY WOULD SUGGEST HIGHS NEAR 50...BUT NOT EXPECTING A LOT OF MIXING WITH THE WARM FRONT NEARBY AND PROBABLY A DECENT AMOUNT OF CLOUDS. KEPT HIGHS NEAR MODEL 2M VALUES...MAINLY LOW 40S. THE ECMWF IS STILL BRINGING A STRONGER SHORTWAVE AND SURFACE LOW TO THE AREA ON SATURDAY THAN THE GFS AND CANADIAN. PLENTY OF MOISTURE TO WORK WITH AMONG ALL MODELS...WITH 2M DEWPOINTS WELL INTO THE 40S...SOME EVEN INTO THE LOW 50S. THE CANADIAN AND GFS ARE NOT SHOWING MUCH IN THE WAY OF PRECIP...BUT DID INTRODUCE POPS SATURDAY PER THE ECMWF SHOWING THIS STRONGER WAVE FOR A COUPLE RUNS NOW. STILL LOOKS LIKE A GOOD AMOUNT OF CLOUDS EVEN WITH THE CANADIAN AND GFS...SO STUCK CLOSER TO 2M TEMPS AGAIN...THOUGH STILL RESULTED IN MILD HIGH TEMPS AROUND 50. WITH NOT MUCH OF A SHORTWAVE AND FRONT SATURDAY...THE GFS KEEPS THE MILD TEMPS GOING INTO SUNDAY...WHILE THE ECMWF BRINGS A BRIEF COOL DOWN. OBVIOUSLY QUITE A BIT OF UNCERTAINTY THIS FAR OUT...SO GENERALLY SPLIT THE DIFFERENCE WITH TEMPS FOR NOW...KEEPING ABOVE NORMAL TEMPS GOING. LOOKS LIKE MILDER AIR COULD LINGER INTO EARLY NEXT WEEK PER THE LATEST GFS AND ECMWF MODEL RUNS. && .AVIATION/12Z TAFS/...FEW CIGS MAY FLIRT WITH MVFR THIS MRNG BUT MOSTLY VFR EXPCD. CLOUDS SHOULD BEGIN TO BREAK UP LATER THIS MRNG AS UPPER JET SHIFTS EWD ALLOWING SUBSIDENCE TO INCREASE OVER SRN WI ALONG WITH INFLUX OF LOW TO MID LEVEL DRIER AIR. && .MARINE...LOW LEVEL WINDS NOT EXPECTED TO BE QUITE AS STRONG EARLY THIS MRNG...HENCE SMALL CRAFT ADVY HAS ALREADY BEEN CANCELLED. NORTHWEST WINDS STILL EXPCD TO REACH 10 TO 20 KTS TODAY AS HIGH PRESSURE BUILDS INTO THE WESTERN GTLAKES AND COLD AIR OVER WARMER LAKE SURFACE CREATING STEEP LOW LEVEL LAPSE RATES. PASSING WEAK SURFACE FRONT WILL RESULT IN VEERING SFC WINDS APPROACHING SMALL CRAFT LEVELS TUE NGT. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...MBK TUESDAY THROUGH SUNDAY...DDV ______________________________________________________________________ --- Site: KMLB --- KMLB - Reference: ['on some timely 0358 and 0633 utc high-res modis images furnished by '] 981 FXUS62 KMLB 040749 AFDMLB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 245 AM EST SUN NOV 4 2012 .DISCUSSION... CURRENT...CLEAR SKIES AND NARROWING T/TD SPREADS HAS ALLOWED SOME MIST TO FORM ACROSS ECFL. MAIN CONCERN IS AREA OF THICKER STRATUS AND DENSE FOG COVERING A GOOK CHUNK OF THE CENTRAL PANHANDLE AND THE NORTHERN/WESTERN PENINSULA. 3.9UM IMAGERY SHOWS THE EASTERN EDGE OF THIS DECK LURKING JUST WEST OF THE CWA. THIS ALSO SHOWS UP NICELY ON SOME TIMELY 0358 AND 0633 UTC HIGH-RES MODIS IMAGES FURNISHED BY NASA/SPORT. WILL NEED TO WATCH THIS AREA CLOSELY AS IT LOOKS LIKE IT COULD SPREAD EAST/SOUTH INTO OUR CWA. AT THE VERY LEAST WILL LIKELY NEED TO ISSUE AN SPS FOR LAKE AND POSSIBLY ADJACENT COUNTIES BEFORE SUNRISE. TODAY/TONIGHT...ASIDE FROM MORNING FOG/STRATUS POTENTIAL...TODAY IS SHAPING UP TO BE ANOTHER SUNNY/DRY DAY WITH COMFORTABLE HUMIDITIES AND A LITTLE WARMER AFTERNOON TEMPS - L80S EVERY BUT THE BARRIER ISLANDS WITH LIGHT WINDS GIVING WAY TO AN AFTERNOON SEA BREEZE. CLEAR WITH PATCHY LATE NIGHT FOG (AND MAYBE A BETTER CHANCE FOR LOW CLOUDS) AGAIN TONIGHT. MINS IN THE U50S/L60S. MON-TUE...RAIN CHANCES RE-ENTER THE FORECAST ON MONDAY AS THE FIRST OF TWO SHORTWAVE PUSHES ACROSS THE MID-ATLANTIC...GENERATING A WEAK SURFACE LOW OVER THE DEEP SOUTH. LOW QUICKLY PUSHES OUT INTO THE ATLANTIC AND BRINGS A FRONTAL BOUNDARY INTO THE CENTRAL PENINSULA ON MONDAY...FORECAST TO STALL OUT DURING THE DAY. A FEW AFTERNOON SHOWERS/SPRINKLES WILL BE POSSIBLE MAINLY N OF THE I-4 CORRIDOR. A RATHER POTENT MID LEVEL WAVE WILL DIG SOUTHWARD ACROSS THE MIDWEST/SOUTHERN MISSISSIPPI VALLEY MONDAY NIGHT INTO EARLY TUES...SPINNING UP A STRONGER SURFACE LOW ALONG THE FRONT IN THE NE GULF TUE MORNING AND EJECTING THIS FEATURE UP THE MID ATLANTIC COAST BY TUESDAY EVENING. SLIGHT TIMING/STRENGTH DIFFERENCES BETWEEN THE GFS/ECMWF...WITH THE GFS BEING THE QUICKER/WEAKER OF THE TWO WITH THE FEATURE AS IT MOVES ACROSS THE NORTHERN HALF OF THE STATE. THE MAIN EFFECT OF THIS ON LOCAL WEATHER WILL BE THE TIMING OF THE FRONTAL PASSAGE...AND PERHAPS RAINFALL AMOUNTS TUES AFTERNOON WITH THE FRONT. HAVE CONTINUE TO SPLIT THE DIFFERENCE AND KEPT THE MENTION OF ISOLATED SHOWERS IN THE FORECAST TUES NIGHT AS THE FRONT SWEEPS THROUGH. OTHERWISE...SCATTERED SHOWERS EXPECTED THROUGHOUT ELECTION DAY. HAVE KEPT THUNDERSTORMS OUT OF THE FORECAST FOR THE MOMENT...BUT MODELS ARE HINTING THAT THERE MIGHT BE ENOUGH INSTABILITY FOR ISOLATED THUNDER MENTION ACROSS THE NORTH AS THE LOW MOVES ACROSS N FL/S GEORGIA. HIGHS IN THE UPPER 70S AND LOW 80S...WITH LOWS IN THE UPPER 50S AND LOW 60S MONDAY NIGHT. TUES NIGHT LOWS WILL BE DEPENDENT ON THE TIMING OF THE FRONTAL PASSAGE...BUT EXPECTED TO DIP INTO THE LOW-MID 50S. WED-FRI...DRY AND COOL WEATHER RETURNS BEHIND THE FRONT FOR THE LATTER HALF OF THE WEEK AS HIGH PRESSURE SETTLES ACROSS THE DEEP SOUTH. HIGH TEMPERATURES IN THE LOW 80S ON MONDAY AHEAD OF THE FRONT...DIPPING INTO THE LOW-MID 70S WED-THURS BEHIND THE FRONT. POST FRONTAL OVERNIGHT LOWS IN THE LOW TO MID 50S WITH A FEW UPPER 40S POSSIBLE IN COOLER INLAND LOCATIONS. && .AVIATION...THRU 13Z WE'LL PROBABLY DEALING WITH LIFR-VLIFR CIGS AND VSBYS IN FG/ST AT KLEE...AND PERHAPS FARTHER EAST TO KISM-KMCO-KSFB IF CLOUD BANK SPREADS EAST. OTHERWISE VFR WITH ANOTHER ROUND OF LOW CIGS/VSBYS POSSIBLE AFTER 07Z SUN NIGHT. && .MARINE...SUN-MON...LIGHT AND VARIABLE WINDS AS A FRONTAL BOUNDARY STALL OVER THE REGION WITH SEAS 2 TO 3 FT. TUE-THU...WINDS WILL INCREASE OUT OF THE WSW TUE AFTERNOON/EVENING AS A SURFACE LOW DEVELOPS IN THE NE GULF AND MOVES ACROSS THE NORTHERN HALF OF OF THE STATE. SPEEDS AROUND 15KTS...PERHAPS CLOSER TO 20KTS IF THE STRONGER AND SLOWER ECMWF SOLUTION VERIFIES. LATEST MODEL RUNS DO NOT HAVE THE POST FRONTAL WINDS QUITE AS STRONG WITH NORTHWEST WINDS 15-20KTS BEHIND THE FRONT LATE TUES NIGHT THROUGH WEDNESDAY. COMBINATION OF THE LOCALLY GENERATED WIND WAVE AND SWELL COMING IN FROM THE DEVELOPING GALE OVER THE ATLANTIC WILL BUILD SEAS TO 5-6FT OFFSHORE AND 3-5FT NEARSHORE INTO WEDNESDAY. WINDS ARE EXPECTED TO DIMINISH TO 10-15KTS ON THURSDAY AS HIGH PRESSURE MOVES INTO THE DEEP SOUTH. && .FIRE WEATHER...MINIMUM RH VALUES OVER THE NORTH INTERIOR WILL DROP INTO THE MID 30S THIS AFTERNOON. DURATION/WIND SPEEDS WILL NOT BE A CONCERN AS FAR AS RFW ISSUANCE GOES. && .PRELIMINARY POINT TEMPS/POPS... DAB 81 60 78 59 / 0 10 20 30 MCO 83 60 81 59 / 0 10 20 20 MLB 80 61 79 61 / 0 10 10 20 VRB 80 59 80 60 / 0 0 10 10 LEE 83 61 81 59 / 0 10 20 30 SFB 82 61 81 60 / 0 10 20 30 ORL 83 62 81 61 / 0 10 20 20 FPR 79 59 79 59 / 0 0 10 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM/AVIATION...CRISTALDI LONG TERM....MOSES ______________________________________________________________________ --- Site: KMOB --- --- Site: KMPX --- --- Site: KMQT --- KMQT - Reference: ['melt the remaining snow across upper michigan. modis satellite'] 526 FXUS63 KMQT 161012 AFDMQT AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 612 AM EDT FRI MAR 16 2012 .SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY EVENING) ISSUED AT 610 AM EDT FRI MAR 16 2012 A BROAD MID-LVL HIGH PRESSURE RIDGE WILL CONTINUE TO DOMINATE THE REGION THROUGH THE WEEKEND MAINTAINING GENERALLY DRY AND UNSEASONABLY WARM WEATHER OVER THE FORECAST AREA. EXPECT PLENTY OF SUNSHINE TODAY FILTERED THROUGH SOME HIGH CLOUDS. INCREASING 925-900MB MOISTURE FM THE SOUTH COULD LEAD TO SCT OR BKN HIGHER BASED CU AS IS OCCURRING OVER PORTIONS OF WI AND LOWER MICHIGAN THIS AFTN. MIXING AOA 900MB SUPPORTS HIGHS INLAND FM THE GREAT LAKES PUSHING WELL INTO THE 60S AND PERHAPS EVEN LOWER 70S OVER THE FAR WRN U.P. TEMPERATURES WILL BE COOLER NEAR THE GREAT LAKES...ESPECIALLY NEAR LK MICHIGAN AS LAKE BREEZE WILL BE ENHANCED BY ALREADY PRESENT GRADIENT S/SE WIND ON FLANK OF SFC HIGH PRESSURE. INCREASING LOW LVL MOISTURE TONIGHT AND DEW POINTS RISING THROUGH THE 40S COULD LEAD TO THE FORMATION OF PATCHY FOG ESPECIALLY OVER THE ERN HALF OF UPPER MI WHICH COULD RECEIVE ADDED MOISTURE IN S-SE FLOW OFF LAKE MI. WITH WARM FRONTAL BOUNDARY EXPECTED TO MOVE UP FROM THE SOUTH OVERNIGHT...LEFT IN A SLIGHT CHC OF SHOWERS OVER MAINLY THE ERN COUNTIES...BUT DRY AND WELL CAPPED MID-LVLS FROM FCST SNDGS SUGGEST DOES NOT BODE WELL FOR INITIATING SHOWERS. GIVEN THAT MODELS HAVE THE WARM FRONT HANGING OVER LAKE SUPERIOR KEPT IN SLIGHT CHC POPS FOR SHOWERS AND POSSIBLE TSRA LATE SAT INTO SAT NIGHT OVER LAKE SUPERIOR AND OVER THE KEWEENAW PENINSULA AND ERN COUNTIES. MODEL SNDGS SHOW MLCAPES INCREASING TO AROUND 1000 J/KG DURING THE DAY ON SATURDAY...BUT AGAIN MLCIN VALUES INDICATE A FAIRLY STRONG CAP IN PLACE SO NOTHING MORE THAN SLIGHT CHC POPS WARRANTED AT THIS POINT. WITH WAA IN MODERATE SSW FLOW EXPECTED...DECIDED TO RAISE HIGH TEMPS ON SATURDAY CLOSER TO REG GEM VALUES WHICH SUGGEST THAT MIXING TO 875 MB SHOULD PUSH HIGHS WELL INTO THE 70S OVER THE WEST HALF OF THE CWA AND PERHAPS EVEN INTO THE LOWER 80S FAR WEST IN A FEW LOCATIONS. SSW OFF LAKE MI WILL RESULT IN COOLER TEMPS EAST HALF...FROM LOWER 50S ALONG LAKE MI TO MID 60S WELL INLAND. .LONG TERM...(AFTER MIDNIGHT SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 610 AM EDT FRI MAR 16 2012 UPPER RIDGE AXIS WILL BE ROTATING THROUGH THE AREA ON SUNDAY. AT THE SFC...WARM FRONT PUSHING N OF THE AREA THROUGH SRN CANADA. THIS WILL BRING AN END TO ANY SLIGHT PCPN CHANCES THAT WOULD BE LINGERING OVER THE AREA ON SAT NIGHT. MODELS SEEM TO BE GETTING A BETTER HANDLE ON THE LLVL MOISTURE. SO OTHER THAN MAYBE A FEW CU DEVELOPING BELOW THE STRENGTHENING H850 INVERSION...EXPECT A PARTLY TO MOSTLY SUNNY DAY. WILL BE LINGERING CLOUDS NEAR LK MI AND E...AS THE FOG BURNS OFF THROUGH THE MORNING HOURS. MIXING TO NEAR H850 WOULD YIELD HIGHS IN THE LOWER 70S OUT WEST AND HAVE BUMPED TEMPS UP TOWARDS THAT. WILL CONTINUE TO BE COOLER OVER THE E WITH THE SRLY FLOW OFF LK MI AND HAVE TEMPS IN THE 50S AND LOWER 60S. UPPER RIDGE AXIS WILL SLOWLY SHIFT NE ON SUNDAY NIGHT WHILE THE AREA REMAINS UNDER SRLY WINDS WITH THE LOW IN THE HIGH PLAINS. MAIN ITEM OF CONCERN IS FOG OVER LK MICHIGAN/SUPERIOR AND HOW FAR INLAND IT WILL PUSH WITH THE SSE WINDS. HAVE TRENDED THEM A LITTLE FARTHER INLAND...BUT OTHERWISE DIDN/T MAKE MANY OTHER TWEAKS. PERSISTANT GRADIENT WIND WILL LIKELY KEEP WINDS AND LOWS UP. HAVE TRENDED TEMPS SLIGHTLY WARMER WITH MID 40S OVER THE E AND LOWER 50S OVER THE WEST. EXTENDED /MONDAY THROUGH THURSDAY/... ANOMALOUS H500 HEIGHTS...AROUND 2-3 STD DEV ABOVE NORMAL FOR MID-LATE MARCH WILL REMAIN OVER THE AREA FOR THE EXTENDED PERIOD. TROUGH OVER AMPLIFYING AND MOVING OVER THE SW CONUS WILL AMPLIFY THE RIDGE UPSTREAM AND LEAD TO CONTINUED WARMING UNDER SRLY FLOW KEEPING WARM AIR IN PLACE. LOW PRESSURE SYSTEM OVER THE HIGH PLAINS WILL PUSH N INTO CANADA ON MON AND START THE SLOW EASTWARD TRANSITION OF THE COLD FRONT ACROSS THE NRN PLAINS AND UPPER MISS VALLEY MON NIGHT THROUGH TUES NIGHT. WITH THE AREA UNDER THE UPPER RIDGE AND SRLY FLOW...STRONG H850 CAPPING WILL BE IN PLACE AND KEEP THE AREA DRY. EXTENDED MODELS HAVE BEEN SLOWLY BACKING AWAY FROM THE COPIOUS LLVL MOISTURE OVER THE LAST COUPLE RUNS...SO EXPECT DAYTIME PERIODS TO BE PARTLY CLOUDY TO MOSTLY SUNNY. WITH THE HIGHER DEWPOINTS FLOWING OVER LK MI/SUPERIOR...EXPECT FOG POTENTIAL TO BE THERE THROUGH MUCH OF THE EXTENDED PERIOD. HAVE SPREAD THIS A LITTLE FARTHER INLAND OFF LK MI DURING THE OVERNIGHT PERIODS AND TAPERED BACK IN THE DAY DUE TO INCREASED MIXING. CONTINUED ABOVE NORMAL TEMPS THROUGH THE PERIOD. TEMPS WILL LARGELY DEPEND ON DEPTH OF MIXING...BUT CURRENT INDICATIONS ARE FOR HIGHS IN THE 60S OR LOWER 70S OVER THE WEST AND 50S OVER THE EAST WITH THE COOLER FLOW OFF LK MICHIGAN. AS FOR THE SECOND HALF OF THE WORK WEEK...00Z GFS ENS MEAN MERGES THE UPPER LOW BACK INTO THE FLOW AS IT MOVES NE INTO THE UPPER MISS VALLEY BY THE END OF NEXT WEEK. 12Z GEM/ECMWF ENS MEANS DO THE SAME THING...BUT ARE SOME HINTS OF IT REMAINING CUTOFF A LITTLE LONGER. EITHER WAY...THIS UPPER DISTURBANCE MOVING TOWARDS THE REGION...ALONG WITH THE WARM TEMPERATURES AND MOISTURE...EXPECT THE BEST CHANCE FOR PCPN TO IN ALL OF THE FORECAST PERIOD DURING THE SECOND HALF OF NEXT WEEK. WILL CONTINUE TO MENTION CHANCES FOR THE WED INTO WED NIGHT...AS THE SLOW PROGRESSION OF THE SFC TROUGH OVER THE NRN PLAINS FINALLY MOVES INTO THE UPPER GREAT LAKES. PCPN CHANCES FOR THURS WILL DEPEND ON IF THIS BOUNDARY DROPS SE OF THE AREA...AS SHOWN ON THE 12Z ECMWF...OR HANGS UP AS SHOWN ON THE 00Z GFS. THIS BOUNDARY WILL THEN DIMINISH AS THE UPPER LOW APPROACHES FOR FRIDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 610 AM EDT FRI MAR 16 2012 EXPECT VFR CONDITIONS TO CONTINUE THROUGH MUCH OF TODAY BUT THEN THERE IS A CHANCE OF STRATUS/FOG FORMATION LATER THIS EVENING AS DEW POINTS BEGIN TO SURGE OVER THE AREA. THE BEST CHC OF LOW MVFR TO IFR CONDITIONS WILL BE AT KSAW IN AN UPSLOPE SSE FLOW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 610 AM EDT FRI MAR 16 2012 EXPECT WINDS LESS THAN 25 KTS INTO NEXT WEEK AS HIGH PRESSURE DOMINATES OVER THE UPR GREAT LAKES REGION. VARIABLE WINDS INITIALLY WILL GIVE WAY TO MORE OF A S/SE WIND THIS WEEKEND AND INTO NEXT WEEK. UNSEASONABLY WARM AIR OVER THE UPPER GREAT LAKES WILL ALSO RESULT IN PERSISTENT MARINE LAYER/STRONG STABILITY OVER THE LAKE. AT SOME POINT...FOG MAY BECOME AN ISSUE...ESPECIALLY IF SOME RAINFALL OCCURS OVER THE LAKE. RIGHT NOW...IT APPEARS DRY WEATHER SHOULD BE THE RULE...KEEPING FOG POTENTIAL LIMITED. && .HYDROLOGY... ISSUED AT 610 AM EDT FRI MAR 16 2012 WARM TEMPERATURES OVER THE NEXT 5 TO 7 DAYS WILL CONTINUE TO MELT THE REMAINING SNOW ACROSS UPPER MICHIGAN. MODIS SATELLITE IMAGERY YESTERDAY SHOWED THAT MUCH OF THE REMAINING SNOW IN WESTERN UPPER MICHIGAN IS LOCATED OVER THE HIGHER TERRAIN. THE SOUTH CENTRAL IS WITHOUT SNOW...BUT MUCH OF EASTERN UPPER MICHIGAN STILL HAS SNOW COVER DUE TO COOLER TEMPERATURES OFF LAKE MICHIGAN. RIVERS ACROSS THE AREA HAVE SHOWN SLOW AND STEADY RISES THIS WEEK...BUT SO FAR NONE HAVE EXCEEDED SPECIFIED BANKFULL VALUES. WITH THE REMAINING SNOW OVER PORTIONS OF UPPER MICHIGAN...STILL HAVE THE POTENTIAL FOR SOME SITES REACHING BANK FULL OVER THE NEXT SEVERAL DAYS. && .CLIMATE... ISSUED AT 610 AM EDT FRI MAR 16 2012 WITH THE VERY ANOMALOUS WARM SPELL WE HAVE BEEN IN...THOUGH IT WOULD BE GOOD TO SHOW WHERE THE NWS MARQUETTE OFFICE STANDS ON SEVERAL MARCH RECORDS. YESTERDAY/S HIGH OF 51 HAS KEPT THE 50 DEGREE DAY STREAK ALIVE...WHICH HAS NOW REACHED 6 DAYS. THE CURRENT RECORD FOR 50 DEGREE DAYS IN A ROW DURING MARCH STANDS AT 7...WHICH RAN FROM 3/24/1993 TO 3/30/1993. THIS SHOULD EASILY BE BROKEN WITH THE EXPECTED TEMPERATURES OVER THE NEXT COUPLE OF DAYS AND SHOULD REACH DOUBLE DIGITS. WE HAVE HAD SEVEN 50 DEGREE DAYS IN MARCH THUS FAR. THE CURRENT RECORD FOR 50 DEGREE DAYS OR WARMER IN MARCH IS 13 AND SET IN 2010. WITH THE WARM WEATHER EXPECTED OVER THE NEXT 7 DAYS...THIS HAS THE POTENTIAL TO BE BROKEN. BUMPING UP TO 60 DEGREE OR WARMER DAYS IN MARCH...5 IS OUR ALL TIME RECORD FROM 2000 AND WE ARE CURRENTLY SITTING AT 2 DAYS...THE 11TH AND 14TH. THE CURRENT FORECAST HAS HIGHS AT OR ABOVE 60 AT NWS MARQUETTE FOR THE NEXT 5 DAYS. MOVING ON TO AVERAGE TEMPERATURES...WE ARE CURRENTLY SITTING AT 21.9 DEGREES FOR THE AVERAGE LOW TEMPERATURE...WHICH CURRENTLY RANKS 4TH FOR MARCH AS A WHOLE. THE ALL TIME RECORD IS 25.9 SET IN 1973...SECOND IS 22.4 IN 2010...AND THIRD IS 22.2 IN 2000. LOOKING AT AVERAGE HIGH TEMPERATURES...THROUGH YESTERDAY WE ARE CURRENTLY TIED FOR THIRD WITH 1987 AT 40.6 DEGREES. THE ALL TIME WARMEST AVERAGE HIGH TEMPERATURE FOR THE ENTIRE MONTH OF MARCH IS 47.1 DEGREES FROM 2010...WITH THE NEXT VALUE OF 43.5 IN 2000. WITH THE EXPECTED TEMPERATURES THROUGH THE END OF THE MONTH...WE WILL LIKELY REACH 2ND ON THE LIST. TO MATCH THE ALL TIME RECORD...WE WOULD NEED TO AVERAGE A LITTLE OVER 53 DEGREES FOR A HIGH EACH DAY THE REST OF THE MONTH. THIS MARCH WILL LIKELY GO DOWN AS ONE OF THE WARMEST EVER. FINALLY...THE WARMEST LOW TEMPERATURE EVER RECORDED AT NWS MARQUETTE IN MARCH IS 44 DEGREES...SET ON 3/31/2010 AND 3/13/1995. THE WARM AND PERSISTENT SOUTHERLY FLOW WILL TRY TO KEEP OVERNIGHT TEMPS UP THROUGH THIS WEEKEND...WHICH SHOULD ALLOW THIS RECORD TO BE BROKEN. WEATHER RECORDS FOR THE MARQUETTE NATIONAL WEATHER SERVICE OFFICE LOCATED IN NEGAUNEE TOWNSHIP DATE BACK TO 1961. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...SRF AVIATION...VOSS MARINE...VOSS HYDROLOGY...SRF CLIMATE...SRF ______________________________________________________________________ KMQT - Reference: ['a little snow cover left at kcmx per latest modis imagery...expect '] 925 FXUS63 KMQT 202340 AFDMQT AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 740 PM EDT TUE MAR 20 2012 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 438 PM EDT TUE MAR 20 2012 ANOTHER INCREDIBLY WARM DAY FOR MARCH IS UNDERWAY WITH TEMPS WELL INTO THE 70S/AROUND 80F OVER ALL BUT THE FAR W...NEAR LAKE MICHIGAN AND LOCALLY ALONG THE SHORES AROUND THE KEWEENAW PENINSULA. ONE MORE SUMMERLIKE DAY IS ON THE WAY FOR WED...THOUGH IT WILL BE COOLER AGAIN NEAR LAKE MICHIGAN AND ALSO OVER THE W WITH INCREASED CLOUD COVER AND SOME PCPN. NRN PORTION OF THE WARM RIDGE OVER THE ERN CONUS WILL BE SUPPRESSED A BIT BY SHORTWAVE NOW MOVING THRU MANITOBA AND THE FOLLOWING WAVE CURRENTLY MOVING ACROSS SRN BRITISH COLUMBIA/SRN ALBERTA. HEIGHT FALLS WILL BE ENOUGH TO SEND SFC COLD FRONT SE INTO THE UPPER GREAT LAKES TONIGHT AND WED. ALTHOUGH MORE SUBSTANTIAL SHRA COVERAGE WILL BE INVOLVED WITH MID/UPPER LEVEL LOW DRIFTING FROM WRN TX TO OK... MOISTURE FEED ALREADY PRESENT ALONG/AHEAD OF FRONT WILL SUPPORT SHRA. PER MORNING SOUNDINGS...PRECIPITABLE WATER VALUES ARE RUNNING 300-400PCT OF NORMAL OVER THE UPPER MISSISSIPPI VALLEY AND WRN GREAT LAKES. FORTUNATELY...STRONG/PERSISTENT FORCING WON'T BE PRESENT TO MAKE THE MOST OF THE AVBL MOISTURE. OTHERWISE...HVY RAINFALL/FLOODING WOULD BE AN ISSUE. MAIN FORCING FOR PCPN WILL COME FROM THE RIGHT ENTRANCE OF UPPER JET SUPPORTING THE SHORTWAVES PASSING BY TO THE N ALONG WITH LOW-MIDLEVEL FRONTOGENESIS. EXPECT SHRA TO BE CONFINED CLOSE TO THE FRONTAL BOUNDARY...AND PROBABLY WITH A PREFERENCE FOR THE COLD SIDE OF THE SFC FRONT. GIVEN SLOW MOVEMENT...FCST WILL SHOW A VERY SLOW SE PROGRESS OF CHC/LIKELY POPS FROM W TO E TONIGHT/WED...AND ONLY AFFECTING THE W TONIGHT AND ONLY REACHING THE E LATE WED AFTN. GIVEN THE AVBL MOISTURE...WILL NEED TO WATCH FOR LOCALLY HVY RAINFALL...BUT AS ALLUDED TO ABOVE...FORCING IS NOT STRONG/SUPPORTIVE OF WIDESPREAD HVY PCPN. WITH RAINFALL OCCURRING OVER LAKE SUPERIOR AND WITH FRONTAL BOUNDARY PROVIDING LOW-LEVEL CONVERGENCE...FOG WILL LIKELY DEVELOP AND BECOME POTENTIALLY WIDESPREAD OVER THE LAKE. IF SO...FOG COULD BECOME AN ISSUE NEAR THE LAKE ONCE WINDS SHIFT ONSHORE WHERE FRONTAL PASSAGE OCCURS WED. IT WILL BE ANOTHER WARM/SUMMERLIKE NIGHT TONIGHT WITH LOWS IN MOST PLACES ONLY FALLING INTO THE 50S...15-20 DEGREES ABOVE THE NORMAL HIGH TEMPS FOR THIS TIME OF YEAR. 40S WILL BE THE RULE NEAR LAKE MICHIGAN. WITH FRONTAL BOUNDARY/CLOUDS AND PCPN OVER THE W...TEMPS WILL BE COOLER THERE WED. EXACT TIMING OF FRONT AND COVERAGE OF SHRA WILL PLAY A BIG ROLE IN TEMPS. FOR NOW...KEPT MAX TEMPS DOWN INTO THE 50S/60S CLOSE TO THE LAKE. TO THE E...SHOULD BE ENOUGH SUN FOR TEMPS TO RISE WELL INTO THE 70S AGAIN OVER CNTRL UPPER MI...TRENDING DOWN TO THE 50S ALONG THE SHORE E OF KESC. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 438 PM EDT TUE MAR 20 2012 CLOUDY WILL DESCRIBE MUCH OF THE PERIOD...EXCLUDING SATURDAY NIGHT THROUGH MONDAY...WHERE DRY WEATHER AND A PARTLY CLOUDY SKY SHOULD DOMINATE THE FORECAST. INCREASED POPS FROM THE KEWEENAW PENINSULA THROUGH BIG BAY...WITH A WETTING RAIN EXPECTED /OVER 0.10IN/ DURING THE EVENING HOURS. LOOK FOR INCREASING SFC PRESSURE LATE WEDNESDAY NIGHT...BEHIND A WEAKENING AND EXITING COLD FRONT SET UP ACROSS THE EASTERN THIRD OF THE CWA. THE SFC HIGH WILL SLOWLY RETREAT NORTHWARD INTO ONTARIO LATE THURSDAY...AS LOW PRESSURE NEARS FROM THE SW THANKS TO THE 500MB CUT OFF LOW OVER THE PLAINS STATES OF OK AND KS WEDNESDAY NIGHT THAT WILL SHIFT TO MO BY DAYBREAK FRIDAY. HEDGE THE ONGOING FORECAST CLOSER TO THE STRAIGHT MODEL DATA TEMP WISE FOR THIS PERIOD. EXPECT THE 500MB RIDGE OVER THE UPPER GREAT LAKES FINALLY EXITING EASTWARD FRIDAY AFTERNOON/EVENING. THE SFC LOW SHOULD LINGER OVER SE MN AND S WI FRIDAY INTO FRIDAY NIGHT...BEFORE SHIFTING SE. THIS TRACK SHOULD BRING THE BEST CHANCE OF RAIN TO W HALF OF UPPER MI FRIDAY...AND THE EAST HALF FRIDAY NIGHT. THE 20/06Z RUN OF THE GFS HAS PUSHED THE 500MB ABOUT 50MI NW OF WHERE IT WAS ON THE 20/00Z RUN...WHICH WAS CLOSER TO THE CONSENSUS OF THE CANADIAN/ECMWF CONSENSUS. EITHER WAY...THESE MORE MID TO EXTENDED RANGE MODELS DO COME BACK INTO AGREEMENT WITH THE LOW BETWEEN OH AND NC SATURDAY NIGHT. THIS WILL ALLOW THE RIDGE THAT HAS BEEN BUILDING ACROSS THE PLAINS TO PUSH OVER THE UPPER GREAT LAKES FROM SATURDAY ON. WHILE A FAST MOVING NORTHERN STREAM TROUGH OVER HUDSON BAY AND CENTRAL ONTARIO MAY IMPACT OUR WEATHER SLIGHTLY OVER THE WEEKEND...IT LOOKS TO BE ONLY A TEMPORARY SUPPRESSION ON THE STRENGTHENING RIDGE WHICH SHOULD BE DIRECTLY OVERHEAD MONDAY NIGHT. TEMPERATURES FOR THE WEEKEND INTO EARLY NEXT WEEK STILL LOOK TRICKY...WITH A COLDER BLAST OF AIR BOTTOMING OUT TO AN AVERAGING -1C BY 18Z MONDAY. AT THE SAME TIME THE GFS IS ALREADY BEING INFLUENCED BY STRONG SOUTHERLY WINDS WITH 850MB TEMPS AROUND 4C /LOWEST AROUND 1.5C AT 12Z SUNDAY/. THE MAIN STORY WILL BE A RETURN OF COOLER...BUT STILL ABOVE NORMAL...TEMPERATURES FOR THE WEEKEND. WHILE HIGH PRESSURE SHOULD ROLL IN FOR THE START OF THE NEXT WORK WEEK...IT SHOULD BE UNLIKE OUR CURRENT WARM SPELL. STILL...850MB TEMPS AROUND 8 TO 10C TUESDAY AFTERNOON COULD BRING ABOUT A BRIEF WARMUP. A STRONG MOISTURE FEED FROM THE GULF...AND SFC LOW CROSSING MN TUESDAY MORNING SHOULD BE ENOUGH TO PRODUCE AT LEAST A SMALL CHANCE OF RAIN FOR W AND CENTRAL UPPER MI. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 740 PM EDT TUE MAR 20 2012 VFR CONDITIONS WILL START THE FORECAST THEN INCREASED MOISTURE AHEAD OF APPROACHING FRONTAL BOUNDARY WILL PRODUCE IFR CIGS AT KIWD AND KCMX. ARRIVAL OF PCPN TO BE DELAYED UNTIL VERY CLOSE TO FRONT BUT WITH WINDS DIMINISHING WILL SEE FOG DEVELOPING OVERNIGHT. WITH STILL A LITTLE SNOW COVER LEFT AT KCMX PER LATEST MODIS IMAGERY...EXPECT IFR VSBYS TO DEVELOP THERE OVERNIGHT. SOME FOG TO ALSO DEVELOP AT KIWD AND KSAW AS WELL BUT SHOULD STAY IN MVFR CATEGORY. AS SHALLOW COOL AIR ENHANCED BY MARINE LAYER ADVECTS INLAND WILL SEE IFR CONDITIONS DEVELOP AT KIWD ABOUT THE TIME THE PCPN ARRIVES EARLY WED MORNING. CONDITIONS TO IMPROVE AT KCMX/KIWD BY MIDDAY AS FORCING ALONG THE BOUNDARY WEAKENS. AT KSAW...EXPECT LLWS AS LOW-LEVEL JET DEVELOPS AHEAD OF FRONTAL BOUNDARY. SOME PATCHY FOG WILL DEVELOP THERE OVERNIGHT BUT WEAK DOWNSLOPE FLOW TO KEEP VSBYS MVFR OR BETTER. OTHERWISE KSAW WILL REMAIN VFR THROUGH THE FORECAST PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 438 PM EDT TUE MAR 20 2012 SOUTHERLY FLOW OVER LAKE SUPERIOR WILL GIVE WAY TO A LIGHT AND GENERALLY VARIABLE WIND REGIME AS A LOW PRESSURE TROUGH SETTLES OVER THE UPPER GREAT LAKES TONIGHT AND WEDNESDAY BEFORE DISSIPATING. ON HIGHER OBSERVING PLATFORMS...SOUTHERLY WINDS THIS EVENING MAY GUST TO AROUND 25KT OVER EASTERN LAKE SUPERIOR WHICH TYPICALLY HAS STRONGER WINDS IN SOUTHERLY FLOW. CLOSER TO THE WATER SURFACE AND DEEPER IN THE CHILLY STABLE MARINE LAYER...WINDS WILL BE LIGHTER. SOME AREAS OF FOG...LOCALLY DENSE...ARE LIKELY OVER THE LAKE THRU WED...THOUGH THE FOG COULD BECOME WIDESPREAD AND DENSE LATER TONIGHT/WED AS RAINFALL OCCURS OVER THE LAKE AND FRONT PROVIDES LOW-LEVEL CONVERGENCE. AS STRONG HIGH PRES RIDGE SHIFTS E ACROSS HUDSON BAY TO QUEBEC THU/FRI AND LOW PRES DRIFTS TO THE OHIO VALLEY...EASTERLY WINDS WILL BE ON THE INCREASE TO 15-25KT. WINDS MAY END UP STRONGEST OVER WRN LAKE SUPERIOR WHERE COASTAL CONVERGENCE/FUNNELING WILL ENHANCE WINDS TO THE W OF THE APOSTLE ISLANDS. WINDS WILL THEN DIMINISH TO 20KT OR LESS SAT INTO SUN AS PRES GRADIENT WEAKENS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...RJT MARINE...ROLFSON ______________________________________________________________________ --- Site: KMRX --- --- Site: KMSO --- --- Site: KMTR --- KMTR - Reference: ['low light visible satellite image is showing mostly clear skies'] 568 FXUS66 KMTR 061607 AFDMTR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 907 AM PDT FRI APR 6 2012 .DISCUSSION...AS OF 9:07 AM PDT FRIDAY...MOSTLY SUNNY SKIES ARE BEING REPORTED ACROSS THE FORECAST AREA THIS MORNING. THE CURRENT LOW LIGHT VISIBLE SATELLITE IMAGE IS SHOWING MOSTLY CLEAR SKIES OVER LAND WITH SCATTERED CUMULUS CLOUDS OVER THE WATERS. OVERNIGHT A COMBINATION OF CLEAR SKIES AND COLD AIR ADVECTION ALLOWED FOR ANOTHER FROST EVENT IN THE INLAND VALLEYS AND CHILLY TEMPERATURES ALONG THE COAST. MONTEREY WFO REPORTED AN OVERNIGHT LOW OF 38 DEGREES WHILE NAPA AIRPORT HIT 33 DEGREES AND KING CITY REPORTED A LOW OF 31 DEGREES. TONIGHT WILL NOT BE NEARLY AS COLD AS LAST NIGHT. THIS IS DUE TO A STORM SYSTEM CURRENTLY POSITIONED AROUND 43 N AND 144 W WHICH IS PUSHING TOWARDS THE WEST COAST. WARM AIR ADVECTION AHEAD OF THIS APPROACHING STORM SYSTEM WILL RESULT IN A GRADUAL WARMING OF THE AIRMASS OVERNIGHT. AT 850MB THE ATMOSPHERE WILL BE AROUND 4 TO 5 DEGREES C AS OPPOSED TO THIS MORNINGS VALUE OF -1.5 DEGREES C. THIS TRANSLATES INTO SURFACE TEMPERATURES IN THE LOW TO MID 40S FOR MOST AREAS OVERNIGHT...MID TO UPPER 30S WILL BE POSSIBLE IN THE SOUTHERN SALINAS VALLEY. WARM SOUTHERLY FLOW WILL CONTINUE AHEAD OF THE PREVIOUSLY MENTIONED STORM SYSTEM PROVIDING PLEASANT CONDITIONS FOR MOST AREAS AROUND THE CWA THIS WEEKEND. AFTERNOON TEMPERATURES WILL REACH INTO THE MID TO UPPER 60S ALONG THE COAST WITH MID 70S POSSIBLE INLAND SATURDAY AND SUNDAY. COOLER TEMPERATURES AND LIGHT RAIN WILL BE POSSIBLE SUNDAY IN THE NORTH BAY AREA. RAIN WILL SLIDE SOUTH TO SANTA CRUZ BY SUNDAY AFTERNOON. BOTH THE 0000 UTC ECMWF AND THE 0600 UTC OPERATIONAL GFS ARE IN GOOD AGREEMENT WITH THE CENTER OF THE LOW AND THE TRACK OF THIS STORM SYSTEM THROUGH AT LEAST MONDAY. BY MONDAY AFTERNOON THE MODEL SOLUTIONS DIVERGE WITH THE ECMWF PUSHING INTO CANADA AND THE GFS SLIDING EASTWARD. REGARDLESS BOTH MODELS THEN SLIDE A NEW LOW PRESSURE SYSTEM INTO THE PACIFIC NORTHWEST BY WEDNESDAY NIGHT THURSDAY MORNING. THIS LOW WILL MAINTAIN A POSSIBILITY OF LIGHT RAIN AND COOLER TEMPERATURES THROUGH THE REMAINDER OF THE FORECAST PERIOD. && .AVIATION...AS OF 4:27 AM PDT FRIDAY...VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. BREEZY WESTERLY FLOW WILL BE POSSIBLE LATER THIS AFTERNOON...BUT NOT EXPECTING THE GUSTY CONDITIONS OBSERVED YESTERDAY AFTERNOON. .VICINITY OF KSFO...VFR THROUGH THE FORECAST PERIOD. WESTERLY WINDS INCREASING AT KSFO THIS AFTERNOON IN THE UPPER TEENS WITH GUSTS IN THE LOW 20S. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINAL...VFR THROUGH THE FORECAST PERIOD. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM && $$ PUBLIC FORECAST: LARRY AVIATION/MARINE: MM ______________________________________________________________________ --- Site: KOAX --- --- Site: KOHX --- --- Site: KOKX --- --- Site: KOTX --- --- Site: KOUN --- --- Site: KPAH --- --- Site: KPBZ --- KPBZ - Reference: ['1km modis pic at 1522z reveals the shallowest cu over nrn wv'] 642 FXUS61 KPBZ 311727 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 127 PM EDT SAT MAR 31 2012 .SYNOPSIS... CLOUDS BREAK UP TONIGHT IN TIME FOR THE NEXT ROUND OF CLOUDS SUNDAY AHEAD OF A LOW PRESSURE SYSTEM DROPPING THROUGH THE GREAT LAKES. HIGH PRESSURE RETURNS MONDAY THEN ANOTHER WEAK SYSTEM PASSES ON TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... 1KM MODIS PIC AT 1522Z REVEALS THE SHALLOWEST CU OVER NRN WV WHICH LEADS TO STRATUS BECOMING OPEN CELLULAR THERE FIRST THEN SPREADING N INTO SWRN PA. DELAYED CLEARING BY SEVERAL HOURS AS SOUNDINGS SUPPORT MOISTURE STAYING TRAPPED UNDER INVERSION AT H9. ALLOWED FOR A PERIOD OF PARTIAL CLEARING THIS EVNG THEN RETURN A LAYER OF STRATUS DURING THE PREDAWN HOURS OVER I-80 AND NRN WV. KEPT MINT TONIGHT AOA WARMEST GUIDANCE TEMPERATURE AS RADIATIONAL COOLING WILL NOT BE THAT SIGNIFICANT. NEXT IN A SERIES OF WEATHER SYSTEMS IN NW FLOW ALOFT TRAVERSES THE AREA SUN AFTN. INCREASED POPS OVER MUCH OF THE AREA TO LKLY...ESPECIALLY IN THE MOUNTAINS WHERE SREF PLUMES INDICATE AROUND A TENTH OF AN INCH OF QPF. THERMODYNAMIC INSTABILITY IS NIL SO CONTINUE TO LEAVE THUNDER MENTION OUT OF FORECAST. && .SHORT TERM /SUNDAY THROUGH MONDAY/... AMPLIFYING RIDGE OVR THE MS VALLEY WILL STEEPEN THE NW FLOW OVER THE AREA DURING THE SHORT TERM. LATEST MODEL RUNS SHOW A SHORTWAVE TROUGH DIVING SOUTHEAST ACROSS THE EASTERN GREAT LAKES SUNDAY INTO SUNDAY NIGHT. MODELS CONT TO INDICATE VARYING DEGREES OF QPF AS THAT FEATURE PUSHES A COLD FRONT ACROSS THE REGION. WL MAINTAIN CHANCE POPS FOR PASSAGE OF THIS SYSTEM...AND HAVE USED A GUIDANCE BLEND WITH COOLER TEMPERATURES THAN PREVIOUS FORECAST FOR MONDAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... WRN STATES TROF IS FORECAST TO DVLP TWD THE PLAINS/WRN LAKES BY MONDAY NGT...PUSHING THE RIDGE ACRS THE ERN HALF OF THE COUNTRY BEFORE DIGGING AN EAST COAST TROF BY THE END OF THE PD. GIVEN MDL DIFFERENCES...HAVE GENLY PERSISTED WITH THE PREVIOUS LONG TERM FORECAST...BUT A BRIEF TEMPERATURE MODERATION AND MID WEEK CDFNT CAN BE ANTICIPATED FOR THE LONG TERM PD. && .AVIATION /17Z SATURDAY THROUGH WEDNESDAY/... WIDESPREAD MVFR CIGS WILL PERSIST THROUGH ABOUT 2Z. A BRIEF PD OF CLEARING WILL OCCUR BEFORE STRATOCU RE-DEVELOPS AFT 7Z ESP AT FKL AND DUJ. FOR AIRPORTS THAT DO NOT SEE OVERNIGHT MVFR CLOUDS...EXPECT MID CLOUDS AHEAD OF THE NEXT WEATHER SYSTEM. OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY... NO WIDESPREAD IFR WEATHER EXPECTED. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ .SYNOPSIS...98 .NEAR TERM...98 .AVIATION...98 ______________________________________________________________________ --- Site: KPDT --- --- Site: KPHI --- --- Site: KPIH --- --- Site: KPQR --- --- Site: KPSR --- --- Site: KPUB --- --- Site: KRAH --- KRAH - Reference: ['polar orbiting satellites show a healthier northern half of the '] 611 FXUS62 KRAH 191832 RRA AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 232 PM EDT SAT MAY 19 2012 .SYNOPSIS... SURFACE HIGH PRESSURE WILL EXTEND SOUTHWARD INTO OUR REGION FROM THE NEW ENGLAND STATES THROUGH THE WEEKEND... WHILE A LOW PRESSURE REMAINS NEARLY STATIONARY OFF THE COAST. && .NEAR TERM /THROUGH SUNDAY NIGHT/... AS OF 230 PM SATURDAY... WATCHING THE SATELLITE IMAGES CLOSELY THIS AFTERNOON AS LOW PRESSURE OFF OF THE CAROLINA COAST HAS GAINED SOME TROPICAL CHARACTERISTICS OVER THE PAST 6 HOURS OR SO. IT IS BECOMING MORE EVIDENT THAT IT IN FACT HAS MAINTAINED ITSELF MUCH BETTER THAN THE STILL VERY WEAK LOW OFF OF THE VIRGINA COAST. THIS SCENARIO WOULD FAVOR THE NAM MODEL SOLUTION OVER THE GFS AND THE ECMWF. THE NATIONAL HURRICANE CENTER IS MONITORING THE SYSTEM AND HAS BEGUN ISSUANCE OF SPECIAL TROPICAL WEATHER OUTLOOKS. AS OF 1155 AM THEY HAVE GIVEN IT A 50 PERCENT CHANCE OF TROPICAL CYCLONE OVER THE 48 HOURS...IF THIS WERE TO OCCUR IT WOULD MOST LIKELY FORM AS A TROPICAL DEPRESSION AND BRING MINIMAL THREATS TO THE NORTH AND SOUTH CAROLINA COASTLINE. WATER TEMPERATURES ARE NOT VERY FAVORABLE FOR TROPICAL DEVELOPMENT AS THEY ARE IN THE LOW 70S WITH A FEW DEGREES HIGHER OVER THE GULF STREAM. POLAR ORBITING SATELLITES SHOW A HEALTHIER NORTHERN HALF OF THE STORM WITH NOT MUCH WRAPPING AROUND THE SOUTHERN SIDE AT THIS TIME. REGARDLESS OF WHAT HAPPENS WITH THE DEVELOPMENT OF THIS SYSTEM... IT IS EXPECTED TO MEANDER OFFSHORE FOR THE NEXT SEVERAL DAYS AND THEREFORE IMPACTS ON THE RALEIGH CWA SHOULD BE MINIMAL IF ANY. AN UPDATE FROM THE NATIONAL HURRICANE CENTER SHOULD BE AVAILABLE LATER THIS AFTERNOON. FOR THE REST OF THE AFTERNOON A PLEASANT BUT BREEZY DAY WITH WINDS OUT OF THE NORTHEAST AT 10-15 KTS WITH GUSTS AS HIGH AS 25 KTS POSSIBLE. TEMPERATURES WILL TOP OUT IN THE MID 70S ACROSS THE AREA. OVERNIGHT TONIGHT COOL BUT SLIGHTLY BREEZY CONDITIONS WILL PREVAIL WITH LOWS IN THE MIDDLE 50S. DRY DEWPOINTS SHOULD KEEP FOG AND LOW STRATUS OUT OF MOST AREAS TONIGHT. FOR TOMORROW WILL MAINTAIN A MOSTLY DRY FORECAST WITH POPS ELEVATED SLIGHTLY IN THE SOUTH AND EAST. CLOUD COVER AND ANY POTENTIAL SHOWERS SHOULD BE LIMITED TO THE TRIANGLE EASTWARDS WITH HIGHER CHANCES OF BOTH FURTHER TO THE EAST. A SLIGHTLY WARMER DAY THAN TODAY WITH TEMPERATURES IN THE MID TO UPPER 70S WITH AND OUTSIDE CHANCE OF AN 80 DEGREE READING IN THE SOUTHWEST. WINDS WILL BE SLIGHTLY RELAXED FROM SATURDAY WITH SUSTAINED WINDS SPEEDS OF 10 KNOTS WITH GUSTS TO 15. LOWS SUNDAY NIGHT WILL BE IN THE UPPER 50S TO LOW 60S. && .SHORT TERM /MONDAY THROUGH THURSDAY/... AS OF 125 PM SATURDAY... MODELS ARE HAVING GREAT DIFFICULTY WITH THE CURRENT LOW PRESSURE AREAS OFF THE VA AND SC COAST. THIS LEADS TO LOWER CONFIDENCE FORECASTS FOR THIS WEEK. IT DOES APPEAR THAT THE DAYS WITH THE HIGHEST CHANCE OF SHOWERS WILL BE MONDAY AND TUESDAY... WITH A POTENTIAL FOR LINGERING SHOWERS INTO WEDNESDAY AND EVEN THURSDAY. THE MOST LIKELY SOLUTION RIGHT NOW APPEARS TO BE THAT ONE MID-UPPER LOW WILL FINALLY GET PULLED NE AWAY FROM OUR REGION MONDAY... BUT IT WILL BE REPLACED BY ANOTHER SHORT WAVE TROUGH THAT WILL APPROACH WESTERN NC LATE MONDAY AND TUESDAY. THIS WAVE WILL HAVE THE POTENTIAL TO CLOSE OFF OVER THE REGION LATE TUESDAY INTO WEDNESDAY (PER THE LATEST NAM). WE WILL CONTINUE TO ADVERTISE THE HIGHEST POP LATE MONDAY AND TUESDAY IN THE WEST... AND TUESDAY IN THE CENTRAL AND EAST. DUE TO THE LOWER CONFIDENCE IN THE MODELS... WE WILL CARRY HIGH CHANCE POPS AND NOT CARRY LIKELY POP UNTIL LATER FORECASTS ARE CONSIDERED. QPF OF 0.50 TO 1.00 INCH FOR THE MON-WED PERIOD SHOULD CONTINUE TO EXTEND THE CURRENT WET PERIOD THAT HAS BEEN GOING FOR SEVERAL WEEKS. SENSIBLE WEATHER WILL INCLUDE... VARIABLY CLOUDY MONDAY WITH A CHANCE OF SHOWERS AND THUNDERSTORMS. WARMER AND HUMID WITH LOWS IN THE 60S. HIGHS 80-85. A CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY. LOWS IN THE 60S. HIGHS 78-84. A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WED-THU. LOWS IN THE 60S. HIGHS IN THE MID 80S. && .LONG TERM /THURSDAY NIGHT THROUGH SATURDAY/... AS OF 125 PM SATURDAY... WITH DIFFERENCES ABOUND IN THE MODEL SOLUTIONS CONCERNING THE DETAILS OF THE SHORT WAVE TROUGH EXPECTED TO AFFECT THE TENNESSEE VALLEY EASTWARD ACROSS THE APPALACHIANS AND NC/VA MID WEEK... WE WILL FOLLOW THE PROPOSED BLEND OF 00Z ECMWF OPERATIONAL AND ENSEMBLE MEAN SOLUTIONS. THIS POINTS TOWARD A BUILDING MID-UPPER LEVEL RIDGE CENTERED OVER THE OHIO VALLEY REGION BY LATE IN THE WEEK. THE OPERATIONAL EC HAS BEEN INDICATING A LINGERING CLOSED MID-UPPER LOW NEAR THE NC/SC COAST INTO FRI AND SAT. GIVEN THE RECENT BOUT WITH CLOSED LOWS OVER OUR REGION LATELY... THIS SOLUTION IS POSSIBLE... BUT IT IS NOT SUPPORTED BY TELECONNECTIONS AND MOST ENSEMBLE FORECASTS. WITH THIS IN MIND... WE WILL TREND TO A DRIER AND WARMER FORECAST BY NEXT FRIDAY AND SATURDAY. IF THE CORE OF THE UPPER RIDGE DOES DEVELOP OVER THE OHIO VALLEY... OUR REGION WOULD STILL BE UNDER THE INFLUENCE OF A NE FLOW OFF THE ATLANTIC. THIS WOULD KEEP OUR REGION COOLER THAN THE AREAS TO OUR NORTH AND WEST WHERE 90+ DEGREE HEAT WILL BE FOUND (LOUISVILLE TO COLUMBUS TO PITTSBURGH AND NEW YORK CITY). OUR MAXIMUM TEMPERATURES BY FRIDAY AND SATURDAY SHOULD BE IN THE MID TO UPPER 80S. LOWS ARE EXPECTED TO BE IN THE MID 60S. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... AS OF 120 PM SATURDAY... HIGH CONFIDENCE OF VFR CONDITIONS THROUGHOUT THE 24 HOUR TAF PERIOD AT ALL SITES. THE MAIN FORECAST PROBLEM OF THE DAY FOR AVIATION WILL BE THE WINDS AS GUSTS OF 20-25 KNOTS ARE POSSIBLE TODAY AT ALL STATIONS. WINDS WILL BE OUT OF THE NORTHEAST AT ALL SITES FOR THE TAF PERIOD. WITH A DRY AIRMASS OVERHEAD THERE IS LITTLE CHANCE FOR FOG OR LOW STRATUS TONIGHT. WINDS WILL REMAIN A BIT ELEVATED OVERNIGHT AT 5-10 KNOTS SO THIS WOULD ALSO HINDER ANY FOG POSSIBILITY. CONDITIONS WILL REMAIN DRY THROUGH 18Z SUNDAY. FOR THE LONG TERM...AS LOW PRESSURE CHURNS OFF THE COAST CLOUDS AND SHOWERS WILL MOVE BACK IN FROM THE EAST LATE SUNDAY INTO MONDAY. KRWI...AND KFAY WILL BE THE TWO SITES MOST AFFECTED BY THIS. WHILE COVERAGE SHOULD BE SPOTTY A FEW MVFR CEILINGS COULD BE POSSIBLE. LATER IN THE WEEK...TUESDAY WILL BE THE BEST CHANCE FOR ADVERSE CONDITIONS WITH A FRONTAL SYSTEM THAT WILL APPROACH THE AREA FROM THE NORTHWEST. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BADGETT NEAR TERM...ELLIS SHORT TERM...BADGETT LONG TERM...BADGETT AVIATION...ELLIS ______________________________________________________________________ --- Site: KREV --- --- Site: KRIW --- --- Site: KRLX --- --- Site: KRNK --- --- Site: KSEW --- KSEW - Reference: ['rates from polar orbiting microwave sensors are about 0.15-0.30 '] 078 FXUS66 KSEW 150952 AFDSEW AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 252 AM PDT THU MAR 15 2012 .SYNOPSIS...A VIGOROUS FRONTAL SYSTEM MOVING THROUGH THE COASTAL WATERS THIS MORNING WILL MOVE THROUGH THE INTERIOR VALLEYS MIDDAY THEN EAST OF THE CASCADES THIS AFTERNOON. THIS FRONT WILL BRING LOCALLY WINDY CONDITIONS AND HEAVY MOUNTAIN SNOW. COOL AND ACTIVE WEATHER WILL DOMINATE THROUGH THE END OF NEXT WEEK AS A SERIES OF DISTURBANCES ROTATE AROUND A DEEP UPPER LEVEL TROUGH NEAR THE WASHINGTON COAST. && .SHORT TERM...A RATHER ACTIVE WEATHER PATTERN WILL DOMINATE OVER THE NEXT WEEK OR SO AS A SERIES OF DISTURBANCES ROTATE AROUND A PROGRESSIVE UPPER LEVEL TROUGH THAT IS CURRENTLY SITTING OVER THE EASTERN PACIFIC. A RATHER STRONG FRONTAL SYSTEM SITS FROM THE NORTH CENTRAL VANCOUVER ISLAND COASTLINE SW TO 42N 133W THEN WESTWARD OUT INTO THE PACIFIC. THE FRONT AND ASSOCIATED JET HAS ENTRAINED SOME TROPICAL MOISTURE THAT ORIGINATES OVER THE WESTERN PACIFIC. WHILE THIS PLUME IS WEAKENING AS IT MOVES ITS WAY ACROSS THE PACIFIC...ONE BAND OF HEAVY RAINFALL NOW SEEN APPROACHING THE COAST WILL PASS ACROSS THE AREA THIS MORNING. THIS WILL ENHANCE OVER THE SOUTH AND WEST FACING OLYMPICS WITH SWLY 850 MB FLOW APPROACHING 70 KT THIS MORNING PER NAM12 BUFR SOUNDINGS. SNOW LEVELS WILL BRIEFLY RISE TO 4000 TO 5000 FEET THIS MORNING THEN FALL BACK TO 3000 FEET OR SO OVERNIGHT TONIGHT S COLD AIR ALOFT MOVES INTO THE AREA BEHIND THE FRONT. RAIN RATES FROM POLAR ORBITING MICROWAVE SENSORS ARE ABOUT 0.15-0.30 INCHES PER HOUR PER NESDIS ESTIMATES. WITH SOME OROGRAPHIC ENHANCEMENT...THE S FACING OLYMPICS COULD SEE 2-3 INCH 12 HOUR RAINFALL AMOUNTS THIS MORNING PER MESO MODELS INCLUDING THE UNIVERSITY OF WASHINGTON WRFGFS 4KM SOLUTION. THE RAINFALL COMBINED WITH SNOW MELT FROM THE WARM PLUME ALOFT WILL GIVE A RAPID RISE TO THE SKOKOMISH RIVER TODAY AND MINOR FLOODING IS POSSIBLE. A FLOOD WATCH HAS BEEN ISSUED FOR THE SKOKOMISH IN MASON COUNTY. HEAVY SNOW WILL FALL IN THE MOUNTAINS ABOVE ABOUT 4000 FEET WITH ANOTHER 6-12 INCHES EXPECTED TODAY. THE MOUNTAINS HAVE ALREADY SEEN 1-2 FEET AND AVALANCHE DANGER IS HIGH. A WINTER STORM WARNING WILL BE MAINTAINED FOR ALL OF THE MOUNTAINS THROUGH 6 PM THIS EVENING. THE AIR MASS ALOFT IS RATHER UNSTABLE OFFSHORE BEHIND THE FRONT WITH 700 MB TEMPERATURES THIS AFTERNOON ALONG THE COAST DOWN TO -20C. SO ISOLATED TSTMS HAVE BEEN PUT INTO THE FORECAST FOR THE COASTAL ZONES AND THE COASTAL WATERS THIS AFTERNOON AND EVENING. A SHOWERY REGIME IS EXPECTED TONIGHT INTO FRIDAY AS UPPER LEVEL TROUGHING LIFTS NORTHEAST ACROSS THE AREA. MODELS ARE INCREASINGLY COMING TO THE CONSENSUS THAT ANOTHER LOW PRES SYSTEM WILL DEVELOP NEAR 41N 130W MIDDAY FRIDAY THEN LIFT NE ACROSS THE CENTRAL OREGON COAST ON ITS WAY INTO THE AREA. THE 00Z GFS AND ECMWF SOLUTIONS TAKE THIS LOW INLAND OVER NW OREGON THEN WEAKEN IT AS IT MOVES INTO EASTERN WA SAT MORNING. THE NAM12 IS FARTHER NORTH TAKING THE LOW INTO W WA. PRECIPITATION CHANCES WILL INCREASE LATER FRI OR FRI NIGHT AS THE LOW APPROACHES...BUT STRONGER WIND WITH THIS LOW SHOULD REMAIN WELL TO THE SOUTH OF THE FORECAST AREA AS THE LOW PASSES BY TO THE SOUTH. SNOW LEVELS WILL DROP TO AROUND 1000 FEET IN SHOWERS SAT THROUGH THE WEEKEND AS A DEEP UPPER LEVEL TROUGH SWINGS ACROSS THE AREA. TEMPERATURES OVER THE WEEKEND WERE LOWERED 2-4 DEG FROM PREVIOUS VALUES WITH THE INCOMING TROUGH. ALBRECHT .LONG TERM...A COOL UPPER TROUGH SWINGING ACROSS THE AREA ON SUNDAY WILL GIVE SHOWERS WITH SNOW LEVELS AROUND 1000 FEET. SNOW LEVELS WILL RISE SOMEWHAT LATER MON INTO TUE AS YET ANOTHER WET FRONTAL SYSTEM APPROACHES THE AREA FROM THE WEST. ANOTHER DEEP TROUGH IS IN STORE FOR LATER NEXT WEEK KEEPING WEATHER ACTIVE. ALBRECHT && .HYDROLOGY...A PERIOD OF RAIN AND HIGHER SNOW LEVELS THIS MORNING WILL GIVE ABOUT A 50 PERCENT PROBABILITY THAT FLOODING WILL OCCUR ON THE SKOKOMISH RIVER IN MASON COUNTY THIS AFTERNOON THROUGH TONIGHT. ANOTHER WET SYSTEM WILL MOVE ACROSS THE AREA ON TUESDAY. SOME MODELS...ESPECIALLY THE 00Z ECMWF INDICATE THAT YET ANOTHER WET SYSTEM WILL MOVE THROUGH THE AREA LATER WED OR THU. THE THREAT FOR FLOODING ON MORE FLOOD PRONE RIVERS DURING THE MIDDLE OF NEXT WEEK APPEARS TO BE INCREASING. WITH THE RAIN OVER THE PAST WEEK...THE AREA IS GETTING CLOSE TO THE THRESHOLD WHERE A LANDSLIDE OUTLOOK WILL BE NEEDED. FOR NOW THE CRITERIA ARE NOT BEING MET BUT THAT DOES NOT PRECLUDE THE THREAT OF ISOLATED LANDSLIDES IN THE AREA. ALBRECHT/SCHNEIDER && .AVALANCHE...A NEARLY CONTINUOUS PARADE OF STORMS BEGAN IN THE OLYMPICS AND NORTH WA CASCADES FRIDAY SPREADING TO THE REMAINDER OF THE CASCADES AND MT HOOD AREA SATURDAY. THE STORM TOTAL AMOUNTS OF SNOW ARE VERY IMPRESSIVE WITH MOST AREAS RECEIVING 3 TO 6 FEET OF SNOW IN THE PAST FOUR DAYS WITH MT BAKER GETTING 8 FEET OVER FIVE DAYS! THIS HEAVY SNOW IS LOADING BURIED WEAK LAYERS AND IS ALL OVERLYING A CRUST LAYER. THE CRUST LAYER SHOULD ACT AS A SLIDING SURFACE MEANING SLIDES BEGINNING IN NEW SNOW LAYERS MAY THEN REACH THE CRUST NOW BURIED UP TO 5 TO 10 FEET OR MORE IN WIND LOADED TERRAIN. AN AVALANCHE WARNING REMAINS IN EFFECT THURSDAY. AS A RESULT OF THESE DANGEROUS AVALANCHE CONDITIONS...ESPECIALLY THROUGH EARLY THURSDAY AS MORE SNOW AND WARMING OCCURS...TRAVEL IN AVALANCHE TERRAIN SHOULD BE AVOIDED BY THURSDAY. THIS STATEMENT WILL BE UPDATED AS CONDITIONS WARRANT. PLEASE VISIT WWW.NWAC.US FOR FURTHER DETAILS. KRAMER && .AVIATION...STRONG WEST SOUTHWEST FLOW ALOFT TODAY WILL BECOME MORE SOUTHWESTERLY AND WEAKEN TONIGHT. AT THE SURFACE STRONG SOUTHEAST GRADIENTS TODAY WILL EASE AND BECOME ONSHORE TONIGHT. AIR MASS IS MOIST AND STABLE. A FRONT WILL REACH THE COAST ABOUT 12Z AND PASS THROUGH PUGET SOUND 16Z-18Z. CEILINGS...CURRENTLY AROUND 5-6K FT...WILL FALL RAPIDLY TO 2-4K FT AS THE FRONT APPROACHES. THERE COULD BE A DIP BELOW 2K FT FOR A FEW HOURS BEFORE FRONTAL PASSAGE AROUND 18Z. VISIBILITY COULD BE AS LOW AS 3-5SM IN RAIN/MIST. SLIGHT IMPROVEMENT IN SHOWERS LATE THIS AFTERNOON AND TONIGHT. KSEA...DISCUSSION ABOVE APPLIES. WINDS WILL BE SOUTHEAST 5-15 KT WITH GUSTS TO 25 KT THIS MORNING...BECOMING SOUTHWEST 12G22 KT AFTER 18Z...THEN EASING TO 6-10 KT IN THE EVENING. CHB && .MARINE...SOUTHEASTERLY GALES NOW OCCURRING ON THE COAST...AT THE ENTRANCES...OVER THE NORTHERN INLAND WATERS...AND IN ADMIRALTY INLET. THESE WILL LAST THROUGH THE MORNING THEN TAPER TO SMALL CRAFT ADVISORY WINDS...EXCEPT ON THE COAST WHERE ONSHORE FLOW 25-35 KT WILL CONTINUE INTO THE AFTERNOON. WINDS ALL AREAS WILL FALL BELOW EVEN SMALL CRAFT ADVISORY SPEEDS TONIGHT. WESTERLY SWELL ON THE COAST WILL PEAK AROUND 15 FT TODAY. ALL WINDS SHOULD BE BELOW 20 KT TONIGHT. ON FRIDAY ONSHORE FLOW STRENGTHENS AND SMALL CRAFT ADVISORY SOUTHWEST WINDS ARE LIKELY. THE NEXT SYSTEM IS A LOW CENTER THAT WILL PASS RIGHT OVER WESTERN WASHINGTON...OR POSSIBLY SOMEWHAT TO THE EAST...AS IT TRAVELS FROM SOUTHWEST TO NORTHEAST. WINDS WILL SWITCH FROM NORTHERLY ON SATURDAY TO SOUTHERLY ON SATURDAY NIGHT AS THE LOW PASSES. ANOTHER SYSTEM WILL REACH THE COAST ABOUT TUESDAY. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...WINTER STORM WARNING FOR THE CASCADES AND OLYMPICS THROUGH TODAY. WIND ADVISORY FOR THE COAST AND NORTH INTERIOR THROUGH EARLY THIS AFTERNOON. FLOOD WATCH FOR THE SKOKOMISH RIVER IN MASON COUNTY THROUGH TONIGHT. PZ...GALE WARNING ALL WATERS EXCEPT CENTRAL STRAIT AND PUGET SOUND. SMALL CRAFT ADVISORY CENTRAL STRAIT AND PUGET SOUND. SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR. $$ WEATHER.GOV/SEATTLE ______________________________________________________________________ KSEW - Reference: ['strong cold front. per noaa polar satellite data...precipitable '] 311 FXUS66 KSEW 201615 AFDSEW AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 915 AM PDT SUN MAY 20 2012 .SYNOPSIS...A WEAK WARM FRONT WILL MOVE ACROSS WESTERN WASHINGTON TODAY GIVING AREAS OF LIGHT RAIN...ESPECIALLY TO THE COAST...MOUNTAINS...AND SOUTH INTERIOR. AN UNSEASONABLY STRONG COLD FRONT WILL BRING SOAKING RAIN AND BREEZY CONDITIONS MONDAY. A DEEP UPPER TROUGH BEHIND THE FRONT WILL USHER IN COOL SHOWERY WEATHER TUESDAY. A COOL AND SHOWERY PATTERN WILL CONTINUE MID TO LATE WEEK...BUT WITH SHOWERS DECREASING AND SOME SUN BREAKS LIKELY. && .SHORT TERM...PACIFIC NW RADARS SHOW AN AREA OF LIGHT RAIN EXTENDING FROM THE COASTS OF OREGON AND WASHINGTON INTO THE SOUTH INTERIOR. THIS LIGHT RAIN IS ASSOCIATED WITH A WEAK WARM FRONT AND IS SHIFTING NORTHEASTWARD WITH TIME. ONE EMBEDDED SHOWER IS GIVING MODERATE RAIN TO CHEHALIS AT 830 AM...BUT MOST OF THE PRECIPITATION APPEARS TO BE RATHER LIGHT. A ZONE UPDATE WAS MADE TO REFINE TEMPERATURES A BIT ALONG THE COAST AND SOUTH INTERIOR AND TO INCREASE THE POPS THERE AND CHANGE THE CHARACTER OF THE RAIN IN THE FORECAST TO PERIODS OF LIGHT RAIN OR OCCASIONAL LIGHT RAIN. AREAS FROM SEATTLE NORTHEASTWARD ACROSS THE INTERIOR MAY TRACE OUT...SO POPS WILL BE LEFT IN THE 50 PERCENT OR GOOD CHANCE CATEGORY. HIGH TEMPERATURES OVER THE INTERIOR WILL BE A BIT TRICKY THIS AFTERNOON. TEMPERATURES STARTED OUT QUITE MILD IN THE MID AND UPPER 50S AND WILL HAVE DIFFICULTY MOVING UPWARD UNTIL THE BAND OF PRECIPITATION MOVES NORTH OF THE AREA. IN THE WARM SECTOR THIS AFTERNOON...THERE MAY BE A 2-4 HOUR PERIOD WHERE PRECIPITATION STOPS...CLOUDS THIN A BIT...AND TEMPERATURES SPIKE INTO THE MID 60S. WHILE THERE IS A CHANCE THAT CLOUDS WILL THIN OUT EARLY THIS EVENING IN TIME TO GIVE A BRIEF GLIMPSE OF THE 80 PERCENT PARTIAL SOLAR ECLIPSE...DONT COUNT ON GOOD ECLIPSE VIEWING ANYWHERE ACROSS WESTERN WASHINGTON. THE SLUG OF SUBTROPICAL MOISTURE THAT HAS BEEN TRACKED ACROSS THE PACIFIC WILL BE PICKED UP AND SLUNG NORTHEASTWARD ACROSS THE AREA LATE TONIGHT INTO MONDAY AHEAD OF AN INCOMING AND UNSEASONABLY STRONG COLD FRONT. PER NOAA POLAR SATELLITE DATA...PRECIPITABLE WATER VALUES WITH THIS SUBTROPICAL FETCH ARE ON THE ORDER OF 1.3 TO 1.7 INCHES AND MAXIMUM RAINFALL RATES WELL OFFSHORE REACH UP TO 0.5 INCHES PER 6 HOURS NEAR 45N/130W PER NESDIS INFORMATION. CURRENT FORECASTS OF 1-2 INCHES OF RAIN LATE TONIGHT THROUGH MONDAY EVENING OVER THE CENTRAL AND SOUTHERN PORTIONS OF THE OLYMPIC PENINSULA APPEAR ON TRACK. AMOUNTS OF AROUND A HALF INCH OVER THE PUGET SOUND LOWLANDS AND UP TO 1.5 INCHES IN THE CASCADES ALSO LOOK GOOD. TEMPERATURES TONIGHT WILL BE HELD IN THE LOWER TO MID 50S MOST AREAS AND WILL STRUGGLE TO HIT 60 ON MONDAY WITH THE RAIN. SNOW LEVELS IN THE MOUNTAINS THROUGH MONDAY WILL BE AROUND 7000 FEET. SNOW LEVELS FALL TO AROUND 4000 FEET LATE MONDAY NIGHT THROUGH TUESDAY BEHIND THE FRONT AS COLD AIR ALOFT WITH AN INCOMING UPPER LEVEL TROUGH APPROACHES. TUESDAY WILL LIKELY BE A BREEZY...SHOWERY...AND UNSEASONABLY COOL DAY. ALBRECHT .LONG TERM...PREVIOUS LONG TERM DISCUSSION FOLLOWS...A BROAD ILL-DEFINED UPPER TROUGH WILL BE OVER THE PACIFIC NORTHWEST ON WEDNESDAY...AS A CLOSED LOW MOVES INTO THE WATERS NORTHWEST OF VANCOUVER ISLAND. WEDNESDAY SHOULD BE A COOL DAY WITH SOME SHOWERS -- AND PROBABLY SOME SUN BREAKS -- BUT THE EUROPEAN MODEL PRECIPITATION AMOUNTS LOOK TOO HIGH. THE LOW WILL MIGRATE SOUTHEAST ACROSS THE PACIFIC NORTHWEST OFFSHORE WATERS THURSDAY FOR ANOTHER FAIRLY COOL DAY WITH SOME SHOWERS...AND THEN INTO NORTHERN CALIFORNIA FRIDAY OR FRIDAY NIGHT. A WEAK UPPER RIDGE WILL DEVELOP OVER THE PACIFIC NORTHWEST BEHIND THE UPPER LOW FOR LESS SHOWERS AND SOMEWHAT WARMER TEMPERATURES. MCDONNAL && .AVIATION...LIGHT SOUTHWESTERLY FLOW ALOFT OVER WESTERN WASHINGTON TODAY WILL BECOME MODERATELY STRONG TONIGHT. WARM FRONT MOVING SOUTH TO NORTH THROUGH THE AREA THIS MORNING INTO THE EARLY AFTERNOON HOURS. AIR MASS MOIST AND STABLE. AT 9 AM PDT...RADAR INDICATES RAIN HAS OVERSPREAD THE COAST...SW INTERIOR...AND IS PUSHING INTO THE PUGET SOUND REGION. IFR VIS/CIGS MAY TEMPORARILY DEVELOP OVER THE SW INTERIOR AT TIMES THROUGH THE MORNING. THIS COULD PRIMARILY IMPACT KOLM AND KHQM. && .MARINE...A WEAK WARM FRONT WILL MOVE FROM SOUTH TO NORTH THROUGH THE AREA THIS MORNING. SLY GRADIENTS ARE NOT EXPECTED TO BE VERY STRONG WITH WINDS BELOW 20 KT TODAY. A COLD FRONT WILL BRING SMALL CRAFT WINDS TO MOST WATERS LATE TONIGHT AND MONDAY. SMALL CRAFT WINDS MAY CONTINUE AT TIMES INTO TUE AND WED AS A PAIR OF SURFACE TROUGHS MOVE THROUGH. ONSHORE FLOW WILL WEAKEN BUT COULD PRODUCE SMALL CRAFT WESTERLIES IN THE CENTRAL/E STRAIT. DTM && .SEW WATCHES/WARNINGS/ADVISORIES... WA...NONE. PZ...NONE. && $$ YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML. ______________________________________________________________________ KSEW - Reference: ['inland late monday afternoon. per noaa polar satellite '] 183 FXUS66 KSEW 202208 AFDSEW AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 308 PM PDT SUN MAY 20 2012 .SYNOPSIS...A WEAK WARM FRONT MOVING THROUGH WESTERN WASHINGTON THIS AFTERNOON WILL LIFT NORTH THIS EVENING. CLOUDS AND SOME LIGHT RAIN WILL CONTINUE BEHIND THIS WARM FRONT. AN UNSEASONABLY STRONG COLD FRONT WILL BRING SOAKING RAIN AND BREEZY CONDITIONS MONDAY. A DEEP UPPER TROUGH BEHIND THE FRONT WILL USHER IN COOL SHOWERY WEATHER TUESDAY. A COOL AND SHOWERY PATTERN WILL CONTINUE MID TO LATE WEEK...BUT WITH SHOWERS DECREASING AND SOME SUN BREAKS LIKELY. && .SHORT TERM...A WEAK AND DIFFUSE WARM FRONT HAS LIFTED INTO NORTHERN PORTIONS OF THE AREA THIS AFTERNOON AND WILL LIFT NORTH OF THE BORDER THIS EVENING. BUT MOIST SW FLOW ALOFT WILL CONTINUE TO BRING PERIODS OF LIGHT RAIN TO THE AREA THIS EVENING. THE SW FLOW ALOFT IS INTERACTING WITH THE OLYMPICS AND IS RESULTING IN THE DEVELOPMENT OF A MESOLOW NE OF THE OLYMPICS. THIS HAS THINNED THE CLOUDS OUT SOMEWHAT AROUND SEQUIM AND IS RESULTING IN SOME BREEZY SOUTHEAST WINDS AROUND WHIDBEY ISLAND AND SQUIRRELLY WINDS THROUGH THE STRAIT OF JUAN DE FUCA. THE ON AND OFF PRECIPITATION THIS EVENING THROUGH THE WEE HOURS OF THE MORNING WILL TEND TO BECOME MORE STEADY FROM THE WEST BEFORE ABOUT SUNRISE. TEMPERATURES TONIGHT IN THE WARM SECTOR WILL GENERALLY HOLD IN THE LOWER TO MID 50S. SATELLITE IMAGERY CONTINUES TO SHOW THE SLUG OF SUBTROPICAL MOISTURE THAT HAS BEEN TRACKED ACROSS THE PACIFIC GETTING PICKED UP AND SLUNG NORTHEASTWARD. THIS FRONTAL RAIN BAND WILL AFFECT WESTERN WASHINGTON THROUGHOUT THE DAY MONDAY AND WILL BE ACCOMPANIED BY BREEZY TO LOCALLY WINDY CONDITIONS. THE FRONT ITSELF IS EXPECTED TO SWEEP INLAND LATE MONDAY AFTERNOON. PER NOAA POLAR SATELLITE DATA...PRECIPITABLE WATER VALUES WITH THIS SUBTROPICAL FETCH ARE ON THE ORDER OF 1.3 TO 1.7 INCHES AND MAXIMUM RAINFALL RATES WELL OFFSHORE REACH UP TO 0.5 INCHES PER 6 HOURS NEAR 45N/130W PER NESDIS INFORMATION. PRE FRONTAL RAINFALL AMOUNTS ARE EXPECTED TO RANGE FROM ABOUT 2/3 OF AN INCH TO 1.5 INCHES ON THE OLYMPIC PENINSULA...1/4 TO 1/2 INCH OVER THE INTERIOR LOWLANDS...AND 1/2 TO 1 INCH IN THE OLYMPICS. THIS IS A PRETTY GOOD SOAKING RAIN FOR LATE MAY. SNOW LEVELS IN THE MOUNTAINS AHEAD OF THE FRONT WILL BE AROUND 7000 FEET. WITH CLOUDS AND PRECIPITATION...TEMPERATURES ON MONDAY WILL STRUGGLE TO MOVE OVER THE 60 DEGREE MARK. SNOW LEVELS FALL TO AROUND 4000 FEET LATE MONDAY NIGHT THROUGH TUESDAY BEHIND THE FRONT AS AN ANOMALOUSLY DEEP UPPER TROUGH FOR THIS TIME OF YEAR MOVES ONSHORE. THE NAM12 AND ECMWF SHOW AN ORGANIZED SURFACE TROUGH OR INSTANT OCCLUSION MOVING ONSHORE TUESDAY AFTERNOON. TUESDAY THROUGH TUESDAY EVENING WILL BE A RATHER RAW...BREEZY AND SHOWERY PERIOD THE AREA. THE MOUNTAINS ABOVE 4000 FEET WILL SEE SOME SNOW AND SEVERAL INCHES OF SNOW ARE POSSIBLE ABOVE ABOUT 5000 FEET...ESPECIALLY ON THE HIGHER WEST SLOPES OF THE OLYMPICS AND THE CASCADE VOLCANOES. THE LOWLANDS WILL NOT GET OUT OF THE 50S ON TUESDAY. THE SPECIAL WEATHER STATEMENT FOR THE UPCOMING WET AND COOL CONDITIONS WILL BE REFRESHED AND REISSUED THIS AFTERNOON. ALBRECHT .LONG TERM...A 130 KT TO 150 KT 300 MB JET WILL PLOW INTO SOUTHERN OREGON TUE THROUGH THU WITH WESTERN WASHINGTON IN THE LEFT EXIT REGION OF THE JET. MODELS GENERALLY DEVELOP A BROAD AND ILL DEFINED UPPER TROUGH TO THE NORTH OF THE JET WITH 500 MB HEIGHTS 545-550 DAM OVER WESTERN WASHINGTON. THE 12Z ECMWF HINTS AT ANOTHER IMPULSE BRINGING SHOWERS WED AND WED EVENING. AN UPPER LOW THEN CLOSES OFF OVER WEST CENTRAL OREGON THU AFTERNOON AND DROPS INTO NORTHERN OR CENTRAL CA FRI. SHOWERS WED WILL LIKELY DECREASE IN COVERAGE ON THU THEN WILL PRIMARILY SHIFT SOUTH OF THE AREA ON FRI. UNCERTAINTY INCREASES THU NIGHT THROUGH THE MEMORIAL DAY WEEKEND AS MODELS HAVE DIFFICULTY WITH THE DETAILS. THE GFS BUILDS A SKINNY RIDGE WITH 568 DAM HEIGHTS OVER W WA LATE IN THE WEEK INTO SAT BEFORE SHIFTING ANOTHER TROUGH SE TOWARD THE AREA FROM THE GULF OF ALASKA. THE ECMWF HAS TROUGHING EXTENDING NORTHWARD FROM THE UPPER LOW INTO EASTERN WA AND HINTS AT RATHER STRONG ONSHORE FLOW. WITH THE UNCERTAINTY...TEMPERATURES WERE BUMPED UP FRI AND SAT BUT NOT TO GUIDANCE VALUES...AND SHOWER CHANCES AND CLOUDS WERE EDGED BACK SOMEWHAT. ALBRECHT && .AVIATION...A STRONG COLD FRONT WILL ENTER THE COASTAL WATERS LATE TONIGHT AND PUSH THROUGH THE INLAND WATERS MONDAY AFTERNOON. THE TRAILING UPPER TROUGH WILL FOLLOW MON NIGHT. MODERATE SW FLOW ALOFT BECOMING STRONG LATER TONIGHT AND MON. STABLE AND VERY MOIST AT ALL LEVELS. PERIODS OF RAIN TONIGHT...HEAVY AT TIMES ON MON. THIS WILL CREATE WIDESPREAD MFR CONDITIONS THE NEXT 24 HOURS WITH IFR CIGS/VIS ALSO LIKELY AT TIMES ACROSS WRN WA. && .MARINE...A WEAK WARM FRONT HAS LIFTED N WITH JUST ENOUGH SE GRADIENT TO CREATE BORDERLINE SMALL CRAFT WINDS IN THE E STRAIT AND ADMIRALTY INLET. THIS SHOULD EASE LATER THIS EVENING...BUT WILL RISE AGAIN ON MONDAY AHEAD OF THE MAIN COLD FRONT. SE WINDS OVER THE COASTAL WATERS WILL ALSO FLIRT WITH SMALL CRAFT CONDITIONS TONIGHT THEN SOLID SLY SMALL CRAFT WINDS TO 30 KT WILL DEVELOP MONDAY. JUST AHEAD OF AND ALONG THE FRONT THE N INTERIOR COULD ALSO GET SMALL CRAFT WINDS AS COULD PUGET SOUND BEHIND THE FRONT MON NIGHT OR TUE. STRONG ONSHORE FLOW TUE AND WED WILL BEGIN TO EASE ON THU. EXPECT SMALL CRAFT WINDS THROUGH THE STRAIT OF JUAN DE FUCA AT TIMES. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...NONE. PZ...SMALL CRAFT ADVISORY COASTAL WATERS THROUGH MONDAY AFTERNOON. SMALL CRAFT ADVISORY EAST ENTRANCE TO THE STRAIT AND ADMIRALTY INLET UNTIL 9 PM THIS EVENING.. && $$ YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML. ______________________________________________________________________ --- Site: KSGF --- --- Site: KSGX --- KSGX - Reference: ['elsewhere. modis tpw image showed the 1-inch precip water values '] 043 FXUS66 KSGX 051026 AFDSGX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN DIEGO CA 330 AM PDT THU JUL 5 2012 .SYNOPSIS... COASTAL LOW CLOUDS WILL PREVAIL THE NEXT SEVERAL DAYS...WITH ONLY PARTIAL CLEARING THIS AFTERNOON BUT WITH BETTER DAYTIME CLEARING FRIDAY AND SATURDAY. TEMPERATURES WILL BE BELOW NORMAL AGAIN TODAY...BUT A WARMING TREND WILL BRING TEMPERATURES BACK TO NEAR OR A LITTLE ABOVE NORMAL THIS WEEKEND AND EARLY NEXT WEEK AS HIGH PRESSURE ALOFT BUILDS OVER THE WESTERN STATES. MOISTURE FROM THE SOUTHEAST WILL BRING A SLIGHT CHANCE OF THUNDERSTORMS TO THE MOUNTAINS AND DESERTS MONDAY THROUGH WEDNESDAY OF NEXT WEEK. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... STRATUS COVERED MOST AREAS W OF THE MTNS...WITH CLEAR SKIES ELSEWHERE. MODIS TPW IMAGE SHOWED THE 1-INCH PRECIP WATER VALUES RETREATED TO CENTRAL/EASTERN IMPERIAL COUNTY AND FAR EAST SAN BERN/RIVERSIDE COUNTIES. GIVEN THE MODERATE DROP IN MID LEVEL MOISTURE AND ONLY A SMALL AMOUNT OF NEAR-ZERO 850MB COMPUTED LI AND A CAP JUST ABOVE 600 MB...WILL KEEP TSTORMS OUT OF THE FORECAST FOR TODAY...BUT SOME CUMULUS WILL DEVELOP OVER THE MTNS. STRATUS WILL BE SLOW TO CLEAR AGAIN...BUT MODELS ARE INDICATING SLIGHTLY LESS RH IN THE COASTAL MARINE LAYER...SO AREAS 3-10 MILES INLAND THAT DID NOT CLEAR WEDNESDAY SHOULD HAVE AT LEAST SOME SUN THIS AFTERNOON. IMMEDIATE COASTAL AREAS WILL HAVE TO WAIT UNTIL AT LEAST FRIDAY. THE LONG WAVE UPPER TROUGH WILL CONTINUE OVER THE NE PACIFIC...BUT THE SHORT WAVE TROUGH OFF THE COAST WILL GRADUALLY WEAKEN THROUGH SATURDAY. THE BIG RIDGE OVER THE PLAINS WILL ALSO RETROGRADE WEST AS A TROUGH DEVELOPS OVER THE NE US. THUS...EXPECT A WARMING TREND...ESPECIALLY INLAND...FRIDAY/SATURDAY. TEMPS WILL GENERALLY BE 8-15 DEG F BELOW NORMAL TODAY...BUT MTN/DESERT TEMPS WILL BE 1-5 DEG F ABOVE NORMAL BY SATURDAY. THE MARINE LAYER WILL BECOME MORE SHALLOW DUE TO THE HEIGHT RISES AND THE SUBSTANTIALLY WEAKER COASTAL EDDY...SO STRATUS WILL BE LESS EXTENSIVE. THE RIDGE WILL BE CENTERED OVER UTAH...SO THE SOUTHWESTERN US WILL HAVE GENERALLY EAST TO SOUTHEAST FLOW ALOFT. ECM/GFS HAVE MID-LEVEL MOISTURE ARRIVING LATE SUNDAY...WITH SLIGHT CHANCES OF TSTORMS OVER THE MTNS BEGINNING MONDAY AFTERNOON DUE TO THE FURTHER INCREASING MID-LEVEL MOISTURE AND MODERATE AMOUNTS OF INSTABILITY. THE MOISTURE WILL MOSTLY BE ABOVE 600 MB THOUGH...SO TSTORMS WILL TEND TO BE MORE ISOLATED...BUT WITH A THREAT OF STRONG GUSTY WINDS. THE TSTORM THREAT COULD CONTINUE THROUGH WED OR THU OF NEXT WEEK...BUT MORE TROUGHING OFF THE PAC NW COAST COULD WEAKEN THE WESTERN US RIDGE AND HENCE WEAKEN THE MOIST SE FLOW THU/FRI. && .AVIATION... 050808Z...THROUGH 1800 UTC OVC STRATUS OVR WATER TO 30SM INLAND WITH BASES 1200-1600 FT MSL AND TOPS 2500-3000 FT MSL OTRW SKC. BTWN 1800-2000 UTC BKN-SCT STRATUS RETREATING W TO COAST...AND FEW-SCT CUMULUS DEVELOPING OVR MTNS IN THE 8000-15000 FT MSL LAYER. BTWN 06/0200-0400 UTC OVC STRATUS MOVING INLAND 25-30SM WITH BASES 1000-1500 FT MSL AND TOPS 2000 FT MSL...AND CUMULUS OVR MTNS ENDING. && .SGX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...MAXWELL AVIATION...BALFOUR ______________________________________________________________________ --- Site: KSHV --- --- Site: KSJT --- --- Site: KSLC --- --- Site: KSTO --- KSTO - Reference: ['as low drops south tuesday night band of showers will develop over the'] 713 FXUS66 KSTO 082207 AFDSTO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SACRAMENTO CA 307 PM PDT MON OCT 8 2012 .SHORT TERM DISCUSSION... UPPER LEVEL LOW JUST OFFSHORE WILL CONTINUE TO INFLUENCE THE NORCAL WEATHER DURING THE WEEK. THIS SYSTEM IS VERY MUCH ON THE DRY SIDE WITH PRECIPTABLE WATER VALUES LESS THAN 0.75 INCHES OVER THE AREA. HAVE INTRODUCE SLIGHT THUNDERSTORM CHANCES OVER THE MOUNTAINS OF SHASTA COUNTY. NAM DEPICTS BEST ELEVATED INSTABILITY OVER THESE AREAS DURING THE LATE AFTERNOON AND EVENING HOURS. HAVE SEEN A FEW STORMS THIS AFTERNOON SOUTH OF BURNEY AND OVER THE COASTAL RANGE. ONSHORE FLOW WILL KEEP COOLER MARINE AIR FLOWING THROUGH THE DELTA INTO VALLEY'S KEEPING TEMPERATURES 5-10 DEGREES BELOW NORMAL OVER THE NEXT FEW DAYS. LOW WILL DROP SLIGHTLY SOUTH TOMORROW...BUT WILL STILL MAINTAIN THE ONSHORE FLOW AND COOLER TEMPERATURES OVER INTERIOR NORTHERN CALIFORNIA. BEST SHOWER CHANCES TONIGHT AND TOMORROW WILL TRANSITION OVER THE SIERRA WITH MOST OTHER LOCATIONS REMAINING DRY. AS LOW DROPS SOUTH TUESDAY NIGHT BAND OF SHOWERS WILL DEVELOP OVER THE SOUTHERN HALF OF THE AREA...AS MOISTURE IS PULLED NORTHWEST. HAVE RAISED POPS TO REFLECT THIS THINKING WITH THE BEST CHANCES OVER THE CENTRAL SIERRA AND SOUTHERN SAN JOAQUIN VALLEY. BEST RAIN CHANCES WILL SHIFT SOUTH WEDNESDAY AND THURSDAY GENERALLY OVER THE SIERRA SOUTH OF INTERSTATE 80. HIGH TEMPS WILL RANGE FROM THE UPPER 70'S OVER THE UPPER SAC VALLEY TO LOW 70'S LOWER SAC VALLEY. && .EXTENDED DISCUSSION (FRIDAY THROUGH MONDAY) THE CLOSED LOW WILL SHIFT EASTWARD INTO THE GREAT BASIN FRIDAY. MODELS CONTINUE TO INDICATE WRAP-AROUND SHOWER BANDS AFFECTING PORTIONS OF THE SIERRA EARLY FRIDAY AS THE LOW DEPARTS. HAVE INCREASED CHANCES FROM AROUND TAHOE SOUTHWARD GIVEN GOOD MODEL CONTINUITY WITH THIS PRECIP. LOCATIONS ABOVE 9000FT MAY SEE THE FIRST DUSTING OF SNOW OF THE SEASON. DRYING AND PARTIAL CLEARING IS EXPECTED LATE FRIDAY INTO SATURDAY AS A SMALL RIDGE BUILDS OVERHEAD...BUT THIS BREAK WILL BE SHORT- LIVED AS THE FIRST IN A SERIES OF PACIFIC SHORTWAVE TROUGHS MOVES INTO THE COAST BY MID-DAY SATURDAY. THE GFS SHOWS A STREAM OF PWAT > 1IN REACHING NORCAL WITH THIS WAVE...WITH CONTINUED HIGH PWAT THROUGH THE REST OF THE EXTENDED. WITH LOW CONFIDENCE IN TIMING AND PLACEMENT OF INDIVIDUAL WAVES...HAVE TRENDED FORECAST TOWARDS CLIMO WHICH FEATURES CHANCES OF RAIN SHOWERS MOSTLY IN THE MOUNTAINS OF SHASTA COUNTY AND WEST OF THE SACRAMENTO VALLEY. -DVC && .AVIATION... VFR CONDITIONS WILL CONTINUE TONIGHT FOR VALLEY TAF SITES. A FEW RAIN SHOWERS WITH AN ISOLATED THUNDERSTORM ARE POSSIBLE THIS EVENING OVER THE MOUNTAINS OF SHASTA COUNTY. BREEZY WINDS OF 10-20 KTS WINDS WILL CONTINUE THROUGH THE CARQUINEZ STRAIT...WITH GENERALLY LIGHT WINDS ELSEWHERE. -DVC && .STO WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ______________________________________________________________________ --- Site: KTAE --- KTAE - Reference: ['shoreline. modis 1km 11-3.9u satellite image from 0703z showed'] 871 FXUS62 KTAE 081011 AFDTAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 511 AM EST Sun Jan 8 2012 .SYNOPSIS...At the surface, a ridge of high pressure remained in place from the Florida Peninsula extending back through the Bahamas. Meanwhile, a cold front had stalled to the north of this area of high pressure, from northern Louisiana into the Carolinas. Other than a few isolated showers, there was no notable precipitation across the southeast corner of the country including our local forecast area. However, the calm winds and (relatively) clear skies associated with the high pressure were contributing to yet another night of fog. The fog was dense in spots, but the expansion of the dense fog was less uniform than in past nights, complicated by a smattering of mid-level clouds slowly traversing north Florida and southern Georgia. The stalled front is likely to remain locked in place over the next several days, and thus persistence will play a large role in the forecast. The focus over the first four days of the forecast is related to a strong upper level closed low that will be ejecting out of the southern Plains, and affecting our forecast area Tuesday and Wednesday. The feature that will eventually develop into this low is in the form of a digging trough currently over the desert Southwest. && .NEAR TERM [through Tonight]...Compared to the past several nights, the development and expansion of dense fog has been more complex early this morning. This is largely because of a few isolated showers in our southwestern areas, and some altostratus that has been slowly moving east across our area. The mid-level clouds have limited fog development across most of southwest Georgia, but it is finally beginning to set in across the rest of the area. We have expanded the Dense Fog Advisory several times, and this will be done once more with the forecast updates recently sent out. The gap in the advisory area from Panama City NNE to Marianna and around the Dothan and Bainbridge areas will be filled in. KECP and KBIJ have already dipped down occasionally to near 1/4SM. Despite a few showers approaching Panama City right now that may cause the fog to temporarily lift, the thinking is that it should set in once more closer to daybreak. This will give us a more uniform advisory area. With forecast soundings for the NAM and local 4km WRF-ARW indicating that the radiation inversion won't break until around 15z, the expiration time of the advisory has been extended an additional hour. After the fog burns off, the focus turns to the possibility of some afternoon showers and thunderstorms. Although the primary surface front will remain north of the area, there should be some increase in low-level moisture advection with the southern edge of a ribbon of stronger 0-2km moisture transport vectors clipping through the northwest third of our forecast area. There is about a 0.3" increase in PWATs through the course of the day over this area. The 4km-WRF runs have been consistent across various flavors of the model in generating some scattered showers in the afternoon. In fact, there appears to be enough instability for some thunderstorms as well. The WRF models, RUC, and NAM forecast soundings all show about 300-500 j/kg of SBCAPE extending up to about the -30C level, so there could be vigorous enough updrafts for some lightning. It looks like another warm day, and with negligible low-level advection the high temperature forecast was a blend of the MAV, MET, and persistence. Highs in the mid-70s should be about 10-15 degrees above normal. && .SHORT TERM [Monday through Tuesday]...Monday is expected to be a quieter day comparatively to Tuesday. Slight shortwave ridging ahead of the approaching trough, and the stalled front remaining north of our area, are expected to keep precipitation chances low. Other than immediately along our northern row of counties, the forecast was kept dry with PoPs generally 5-10%. Partly cloudy skies and a similar low-level temperature profile to what we are experiencing this weekend should support another day with highs in the mid-70s. For Tuesday, the closed upper level low will kick out from the southern Plains and begin migrating east across the Gulf Coast states. During the day, there should be a slow ramp-up in cloud cover and precipitation chances from west to east. By 00z Wednesday the majority of the models have the 500mb low centered near Shreveport, LA, and thus the bulk of the deeper layer QG convergence will still be focused to the west of our area. As such, PoPs were kept on the low end of the guidance envelope. However, we are still expecting some scattered showers to develop over most of the area by Tuesday afternoon as low-level WAA increases. Models are very reluctant to show much instability prior to 00z Wednesday, and this makes sense as the colder core of the mid-upper level low will remain west of our area. Therefore, we were slow to introduce thunder during the day time. It looks like most of the thunderstorm threat would be after dark, and that is discussed in more detail below. && .LONG TERM [Tuesday Night through next Sunday]...Guidance has come into good agreement for the early portion of the extended forecast period. Upper low/sfc low will begin the period situated near the Arklatex, with a cold front reaching southeast to the Mississippi coast and into the Gulf. As the system moves eastward through the overnight hours, good divergent pattern aloft will aid in maintaining broad area of large scale lift and resulting precipitation. Guidance also shows a 60-70kt mid-level jet moving into the panhandle and reaching the Big Bend by sunrise on Wednesday. This jet, along with significant low-level directional and speed shear, will create a very favorable kinematic environment for rotating storms. The weak parameter for severe weather continues to be the amount of instability available. 00Z GFS and Canadian are a bit more aggressive than the 00Z Euro with respect to low-level instability, each showing up to around 500j/kg of BL CAPE right along the front. With the favorable shear parameters, this would likely be sufficient to maintain a few severe thunderstorms Tuesday night into Wednesday morning as the front sweeps across the forecast area. Will continue to monitor this potential severe weather event closely over the coming days. Much drier air will push in behind the front during the day on Wednesday. However, without much in the way of cold air in waiting, temperatures will only modestly cool off. Significant uncertaintly exists as Friday and the weekend approaches. Guidance has reversed itself over the past few days, with the GFS now indicating a wet Gulf low by the end of the week, while the Euro maintains a dry frontal passage. The guidance was roughly reversed with the scenario 48 hours ago. Since the GFS has maintained this solution for a couple of runs, and has some support from the 00z Canadian, will begin to nudge PoP up for Thursday night through Friday as low pressure develops over the western Gulf and lifts east-northeastward. A colder airmass is expected to follow this system into the area for next weekend. && .MARINE...The main marine concern over the first 48-60 hours of the forecast is related to fog. A Marine Dense Fog Advisory was hoisted through 16z for our coastal zones within 20 NM of the shoreline. MODIS 1km 11-3.9u satellite image from 0703z showed some hints of fog over the waters, especially over protected bays and waterways. Another prominent area of fog was located between Alligator Point and the mouth of the Aucilla River along the northern rim of Apalachee Bay. It is uncertain if or when this fog will dissipate, and that is something the subsequent shift will have to examine in greater detail. As moist southeasterly flow continues over the next several days and dewpoints steadily climb, sea fog will likely be a continued concern over various parts of the waters. The predictability of this is low, but the extended potential for fog will be highlighted in the HWO and the synopsis section of the CWF. Advisory-level winds still look like a good bet around the cold front passage later Tuesday and very early Wednesday. The other concern would be related to surf heights on the Panhandle beaches Tuesday-Wednesday. The latest 06z run of the SWAN yields 3-4 foot surf along Walton County Tuesday, and around 2 feet elsewhere. This increases to 4-5 feet on most Panhandle beaches for Wednesday. This doesn't quite hit Surf Advisory criteria, but nonetheless stronger and more frequent rips should become likely by Tuesday afternoon. && .AVIATION [through 06z Monday]...Dense fog and conditions near airport minimums will continue to plague area terminals through the morning hours. An area of mid-level clouds is currently moving across southwest Georgia and the western Big Bend. This cloud deck will limit poor conditions at KABY and possibly result in some improvement at KTLH by 08-09Z. The lingering clouds at KECP should also keep conditions generally above airport minimums. VFR conditions are anticipated at all terminals by late morning as the fog burns off. However, fog will once again be an issue Sunday night. && .FIRE WEATHER...A moist low-level airmass will remain in place across the region into the middle of next week, with RH values remaining well above critical levels. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 75 48 76 50 73 / 20 10 10 10 30 Panama City 70 57 73 58 69 / 20 10 10 20 50 Dothan 74 53 74 54 71 / 40 30 10 20 50 Albany 73 52 75 51 72 / 30 30 10 10 40 Valdosta 75 48 76 49 74 / 10 10 10 10 30 Cross City 76 47 76 48 74 / 0 10 10 10 20 Apalachicola 69 55 71 58 68 / 10 10 10 10 40 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...Dense Fog Advisory until 9 AM CST this morning for Coffee-Dale- Geneva-Henry-Houston. GA...Dense Fog Advisory until 10 AM EST this morning for Brooks- Decatur-Early-Grady-Lowndes-Miller-Seminole-Thomas. FL...Dense Fog Advisory until 10 AM EST /9 AM CST/ this morning for Calhoun-Central Walton-Coastal Bay-Coastal Dixie-Coastal Franklin-Coastal Gulf-Coastal Jefferson-Coastal Taylor- Coastal Wakulla-Gadsden-Holmes-Inland Bay-Inland Dixie- Inland Franklin-Inland Gulf-Inland Jefferson-Inland Taylor- Inland Wakulla-Inland Walton-Jackson-Lafayette-Leon-Liberty- Madison-South Walton-Washington. GM...Dense Fog Advisory until 11 AM EST this morning for Apalachee Bay-Coastal waters From Ochlockonee River to Apalachicola FL out to 20 NM-Coastal waters from Suwannee River to Keaton Beach FL out 20 NM-Coastal waters from Apalachicola to Destin FL out 20 NM. && $$ Synopsis & Near Term...Lamers Short Term...Lamers Long Term...Camp Marine...Lamers/Camp Aviation & Fire Wx...Camp ______________________________________________________________________ --- Site: KTBW --- --- Site: KTFX --- --- Site: KTOP --- --- Site: KTSA --- --- Site: KTWC --- --- Site: KUNR --- --- Site: KVEF --- --- Site: PAFC --- --- Site: PAFG --- PAFG - Reference: ['this afternoons polar orbiting satellite imagery shows the clouds'] 004 FXAK69 PAFG 090125 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 425 PM AKST SUN JAN 8 2012 .DISCUSSION... THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS ARE IN GOOD AGREEMENT THROUGH TUESDAY. BOTH MODELS FORECAST A LARGE TROUGH OF LOW PRESSURE ALOFT TO HOLD OVER THE BERING SEA THROUGH TUESDAY. THE GFS FORECASTS A SEPARATE LOW ALOFT ABOUT 500 MILES SOUTH OF ATTU TO MOVE EASTWARD TONIGHT...AND THEN TO MOVE NORTHEASTWARD MONDAY AND TUESDAY. THE NAM MODEL FORECAST INCORRECTLY MISSES THIS FEATURE. BOTH MODELS FORECAST STRONG WESTERLY WINDS ALOFT OVER THE SOUTHERN BERING SEA AND THE SOUTHERN MAINLAND OF ALASKA TO CONTINUE TONIGHT. AS STRONG HIGH PRESSURE ALOFT BUILDS NORTHWARD OVER THE GULF OF ALASKA MONDAY...THEN OVER SOUTHEAST ALASKA ON TUESDAY...MODERATE SOUTHWESTERLY WINDS ALOFT WILL DEVELOP OVER ALL OF NORTHERN ALASKA. THIS WILL BE FOLLOWED BY GRADUALLY WEAKENING SOUTHERLY FLOW ALOFT WEDNESDAY. FROM THURSDAY THROUGH SATURDAY...AS THE TROUGH ALOFT MOVES EASTWARD INTO THE YUKON...MODERATE NORTH WINDS ALOFT WILL DEVELOP OVER NORTHERN ALASKA. THE ORIGIN OF THESE NORTH WINDS ALOFT WILL BE IN THE VERY HIGH ARCTIC. TEMPERATURES ALOFT WILL BE QUITE COLD...EXCEPT FOR A BRIEF REMISSION FROM TUESDAY AND WEDNESDAY WHEN SOUTHWEST WINDS ALOFT BRING IN MORE MODERATE TEMPERATURES TO THE INTERIOR. ON THURSDAY THROUGH NEXT TUESDAY / JANUARY 12 THROUGH JANUARY 17 /...NORTH WINDS ALOFT WILL CONTINUE AN INFLUX OF COLD ARCTIC AIR OVER THE REALM. IN THIS PATTERN OF WIND FLOW ALOFT...THE MILDEST TEMPERATURES ALOFT AND AT THE SURFACE WILL BE OVER SAINT LAWRENCE ISLAND AND THE CHUKCHI SEA. THIS AFTERNOONS POLAR ORBITING SATELLITE IMAGERY SHOWS THE CLOUDS THAT COVERED THE EASTERN AND CENTRAL INTERIOR ARE MOVING EASTWARD. CLEAR SKIES AND EXTENSIVE AREAS OF TEMPERATURES IN THE 40S BELOW ARE NOW EXPANDING FROM THE WEST INTO THE CENTRAL INTERIOR. EASTERN INTERIOR HIGHLANDS WILL CONTINUE TO HAVE BRISK SOUTHWEST WINDS...POOR VISIBILITY IN BLOWING SNOW...AND WIND CHILLS TO 55 BELOW TONIGHT AND MONDAY. A COUPLE OF INCHES MORE SNOW IS EXPECTED TONIGHT OVER THE EASTERN INTERIOR DURING THE NEXT 18 HOURS. WHEN SOUTHWESTERLY FLOW ALOFT PREVAILS OVER ALL OF THE REALM ON MONDAY AND TUESDAY...THE WESTERN MAINLAND WILL BECOME CLOUDY AND HAVE SOME LIGHT SNOW. THE ARCTIC ORIGIN OF THE INBOUND FLOW STARTING ON WEDNESDAY WILL RESULT IN LITTLE SNOWFALL FROM THIS THURSDAY INTO NEXT WEEK. A MODERATE NORTH PACIFIC LOW PRESSURE SYSTEM HEADED TOWARD THE ALASKA PENINSULA WILL BRING INCREASING NORTH WINDS TO THE BERING SEA COAST AND THE WESTERN INTERIOR STARTING ON TUESDAY. OVERALL,,.ASIDE FROM THE BRIEF RISE IN INTERIOR TEMPERATURES TUESDAY AND WEDNESDAY...NORTHERN ALASKA WILL HAVE CONTINUED COLD WEATHER ALL WEEK THIS WEEK AND MOST OF NEXT WEEK. && .AFG WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY FOR AKZ201-AKZ203-AKZ205-AKZ207-AKZ212- AKZ213-AKZ214. WINTER WEATHER ADVISORY FOR AKZ220. BRISK WIND ADVISORY FOR PKZ225-PKZ230. && $$ TF JAN 12 ______________________________________________________________________ PAFG - Reference: ['1225z poes shot continues to show areas of status along parts of'] 850 FXAK69 PAFG 171320 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 420 AM AKST TUE JAN 17 2012 .DISCUSSION... A BLOCKY PATTERN ALOFT WILL CONTINUE FOR THE NEXT SEVERAL DAYS AS AN OMEGA BLOCK GRADUALLY TRANSITIONS TO MORE OF A REX BLOCK BY LATE IN THE WEEK. A STRONG 572 DM CLOSED HIGH ALOFT OVER THE GULF OF ANADYR THIS MORNING WILL VERY SLOWLY DRIFT TO THE WEST AND WEAKEN THROUGH SAT. DEEP LOWS ARE FOUND IN THE SEA OF OKHOTSK AND IN NORTHERN CANADA. THE LOW IN THE SEA OF OKHOTSK WILL DROP SOUTH OF THE ALEUTIANS FORMING A QUASI REX BLOCK. THE LOW IN CANADA IS EXPECTED TO EVENTUALLY DIG INTO NORTHERN ALASKA AS IT JOINS FORCES WITH SOME SHORTWAVE ENERGY THAT MOVES OVER THE TOP OF THE STRONG RIDGE BY THE WEEKEND. SFC...A STRONG HIGH PRESSURE COVERS MUCH OF NORTHERN ALASKA THIS MORNING WITH SFC PRESSURE IN MOST AREAS GREATER THAN 31.00 INCHES OF MERCURY. THE SURFACE HIGH WILL ONLY SLOWLY WEAKEN THE NEXT COUPLE OF DAYS. A 983 MB LOW JUST NORTH OF VICTORIA ISLAND IN NORTHERN CANADA WILL MOVE SLOWLY TOWARD THE WESTERN SHORE OF THE HUDSON BAY...AND GRADUALLY WEAKEN THROUGH THURSDAY. INTERIOR...QUITE COLD IN THE VALLEYS THAT CLEARED OUT WITH MANY SPOTS IN THE 40 TO 50 BELOW RANGE. SOME STATUS STILL HANGING ALONG THE NORTHERN FOOTHILLS OF THE WESTERN ALASKA RANGE AND UP TO ABOUT NENANA EARLY THIS MORNING. CLOUDS SHOULD GRADUALLY CLEAR OUT OF THE REMAINING CLOUDY AREAS TODAY. 850 MB TEMP OF -20C ON THE 12Z PAFA SOUNDING WITH SOME SLOW WARMING ALOFT TO CONTINUE THE NEXT COUPLE OF DAYS. THIS WILL MAKE FOR SHALLOWER INVERSIONS AND LARGER TEMP SPREADS FROM THE VALLEY FLOOR TO THE HILLS. AREAS OF DENSE ICE FOG WILL LIKELY PERSIST THROUGH TONIGHT IN THE URBAN AREAS AROUND FAIRBANKS...WITH SOME BRIEF IMPROVEMENT IN THE VISIBILITY POSSIBLE FOR A FEW HOURS THIS AFTERNOON. NORTH SLOPE...THE MAIN CONCERN IN THE SHORT TERM WILL CONTINUE TO BE A PROTRACTED BLIZZARD ALONG THE EASTERN BEAUFORT SEA COAST. THE VSBY SENSOR AT BARTER ISLAND STOPPED REPORTING AROUND 18Z YESTERDAY...BUT BASED ON THE WIND THAT CONTINUES TO GUST TO NEAR 65 MPH IT IS PRETTY GOOD BET THAT SEVERE BLIZZARD CONDITIONS ARE CONTINUING. LITTLE CHANGE IN THE WIND IS EXPECTED TODAY WITH THE GRADIENT EXPECTED TO SLOWLY RELAX BEGINNING WEDNESDAY AS SFC PRESSURES SLOWLY FALL ACROSS NORTHERN AK AND THE LOW NORTH OF VICTORIA ISLAND SLOWLY FILLS AND BEGINS TO MOVE OFF TOWARD THE WESTERN SHORE OF THE HUDSON BAY. BLOWING SNOW WILL LIKELY REDUCE THE VSBY TO ONE HALF MILE AT TIMES AS FAR WEST AS DEADHORSE THROUGH TONIGHT SO THE WINTER WEATHER ADVISORY LOOKS GOOD. THE WIND QUICKLY DROPS OFF AND BECOMES LIGHT ALONG THE WESTERN ARCTIC COAST. WIND TO ABOUT 20 MPH AT BARROW TODAY...BUT TEMPS ARE NOT QUITE LOW ENOUGH FOR A WIND CHILL ADVISORY. A WINTER WEATHER ADVISORY WAS ISSUED ON THIS SHIFT FOR ATIGUN AND ANAKTUVUK PASS TODAY FOR THE COMBINATION OF POOR VISIBILITY IN BLOWING SNOW AND LOW WIND CHILLS. ATIGUN HAS BEEN GUSTING TO OVER 30 MPH MUCH OF THE NIGHT...WHICH IS USUALLY AN INDICATION THAT THERE ARE GOING TO BE SOME ISSUES WITH BLOWING AND DRIFTING SNOW AND POOR VISIBILITY. WEST COAST...QUIET WEATHER ALONG THE WEST COAST THE NEXT FEW DAYS. 1225Z POES SHOT CONTINUES TO SHOW AREAS OF STATUS ALONG PARTS OF THE WEST COAST THAT HAVE BEEN CLEARING OUT FROM THE EAST DURING THE LAST 12 TO 18 HOURS. MAINLY NLY FLOW ALOFT TO PERSIST THE NEXT FEW DAYS AROUND THE HIGH PRESSURE IN EASTERN RUSSIA. TEMPS IN SOME OF THE INTERIOR VALLEYS THAT CLEAR OUT WILL BECOME QUITE COLD...BUT NOT AS COLD AS EARLIER THIS MONTH WHEN THE AIR MASS ALOFT WAS MUCH COLDER. THE AIR MASS ALOFT WILL CONTINUE TO MODERATE THE NEXT COUPLE OF DAYS LIKELY RESULTING IN SOME STEEP INVERSIONS IN THE INTERIOR VALLEYS. MEDIUM RANGE...THE MODELS HAVE COME TO A FAIRLY COMMON SOLUTION FOR MUCH OF THE MEDIUM RANGE. DECENT AGREEMENT BETWEEN THE OPERATIONAL GFS AND ECMWF AND THEIR ENSEMBLE MEANS. THERE ARE SOME DIFFERENCES IN TIMING...BUT OVERALL GOOD AGREEMENT. A COLD UPPER LOW OVER THE CANADIAN ISLANDS LATE THIS WEEK IS EXPECTED TO JOIN FORCES WITH SOME SHORTWAVE ENERGY THAT SPILLS OVER THE RIDGE. A DEEP UPPER TROUGH IS EXPECTED TO DROP INTO THE ARCTIC COAST OVER THE WEEKEND AND PUSH SOUTH AND INTO THE GULF OF ALASKA BY SOMETIME EARLY NEXT WEEK. THE MODELS DO DIFFER A BIT ON THE TIMING AND POSITION OF THE LOW AS IT MOVES SOUTH AND ON THE AMOUNT OF RETURN FLOW INTO THE INTERIOR. A SFC LOW IN THE GULF OF ALASKA COULD POTENTIALLY LEAD TO SOME ISSUES WITH LOW WIND CHILLS AND BLOWING SNOW ON THE SUMMITS SOMETIME OVER THE WEEKEND. && .CLIMATE...THE AVERAGE TEMPERATURE OF -25.9 DEGREES AT THE FAIRBANKS INTERNATIONAL AIRPORT IS NEARLY 18 DEGREES BELOW THE 30-YEAR AVERAGE TEMPERATURE. MONTH TO DATE...IT HAS BEEN THE COLDEST START TO JANUARY SINCE 2000...AND RANKS AS THE 2ND COLDEST START TO THE MONTH OF JANUARY IN THE LAST 30 YEARS. SO FAR...THERE HAVE BEEN 11 DAYS OF 40 BELOW COLD THIS MONTH...STILL FAR FROM THE RECORD OF 21 BACK IN 1971. CB && AVIATION...SFC PRESSURE AT MOST SITES IN NORTHERN AK IS GREATER THAN 31.00 INCHES OF MERCURY THIS MORNING. THE SFC PRESSURE SHOULD FALL BELOW 31.00 INCHES IN MOST AREAS BY TONIGHT. && .AFG WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY FOR AKZ222. BLIZZARD WARNING FOR AKZ204. WINTER WEATHER ADVISORY FOR AKZ203 & AKZ206. GALE WARNING FOR PKZ245. BRISK WIND ADVISORY FOR PKZ240. && $$ CB JAN 12 ______________________________________________________________________ PAFG - Reference: ['this mornings polar orbiting weather satellite imagery shows clear'] 457 FXAK69 PAFG 051451 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 551 AM AKST MON MAR 5 2012 .DISCUSSION... THE GFS AND NAM COMPUTER WEATHER FORECAST MODELS FORECAST A BERING SEA WEATHER FRONT TO MOVE ON SHORE OVER THE BERING SEA COAST THIS MORNING...AND TO REACH THE CENTRAL INTERIOR TONIGHT. THIS IS TO BE FOLLOWED BY BRISK WESTERLIES ALOFT THROUGH TUESDAY EVENING. THIS MOBILE PATTERN IS FORECAST TO SHIFT BACK TO WHAT WE HAVE HAD FOR MUCH OF THIS WINTER...A LARGE AREA OF COLD LOW PRESSURE ALOFT OVER MAINLAND ALASKA WILL BE REESTABLISHED WEDNESDAY...AND IS FORECAST TO HOLD THROUGH MOST OR ALL OF NEXT WEEK. THE INCOMING WEATHER FRONT FROM THE BERING SEA HAS BROUGHT A SUDDEN ONSET OF SNOW AND BRISK EAST WINDS TO THE BERING SEA COAST OF NORTHERN ALASKA. THE AREA OF SNOW IS EXPECTED TO RAPIDLY EXPAND OVER THE SOUTHWESTERN AND CENTRAL INTERIOR BY THIS EVENING...AND OVER THE EASTERN INTERIOR TONIGHT AND TUESDAY MORNING. MOST OF THE ENERGY AND PRECIPITATION FROM THE BERING SEA WEATHER FRONT IS FORECAST TO BE DIRECTED EASTWARD. BRISK SOUTHWEST WINDS WITHIN 5000 FEET OF SEA LEVEL ARE FORECAST TO BRING STRONG SOUTHWEST WINDS AND BLOWING SNOW TO HIGHLAND SUMMITS OF THE INTERIOR SOUTH OF FORT YUKON AND BETTLES TONIGHT...AND TO CONTINUE TUESDAY. THE HEAVIEST SNOWFALL WILL BE OVER THE SOUTHWESTERN INTERIOR DURING THE NEXT 24 HOURS. A SERIES OF SHORT WAVES ALOFT IS LIKELY TO MOVE EASTWARD OVER NORTHERN ALASKA STARTING TONIGHT. IN FAST MOVING FLOW ALOFT SUCH AS THERE IS PREDICTED FOR THE NEXT 36 HOURS...THE DETAILS OF THESE SHORT WAVES ARE DIFFICULT TO PREDICT. AS THE COLD TROUGH OF LOW PRESSURE ALOFT SETTLES DOWN OVER THE ALASKA MAINLAND STARTING TUESDAY NIGHT...SCATTERED SNOW SHOWERS CAN BE EXPECTED TO BRING A PATTERN OF UNEVEN SNOWFALL. COLDER TEMPERATURES ARE EXPECTED TO RETURN STARTING WEDNESDAY EVENING AS THE COLD LOW ALOFT FURTHER EXPANDS OVER MAINLAND ALASKA. THIS MORNINGS POLAR ORBITING WEATHER SATELLITE IMAGERY SHOWS CLEAR SKIES AND 40 TO 50 BELOW TEMPERATURES OVER THE CENTRAL AND WESTERN BROOKS RANGE...AS WELL AS SOME VALLEYS IN THE NORTHEASTERN INTERIOR. OVERCAST STRATOCUMULUS WHICH HAD PERSISTED OVER THE CENTRAL INTERIOR FOR DAYS IS NOW HEADED SOUTHEASTWARD OVER THE YUKON TANANA UPLANDS AND THE CENTRAL AND EASTERN ALASKA RANGE. && .AFG WATCHES/WARNINGS/ADVISORIES... WIND CHILL WARNING FOR AKZ204. WINTER WEATHER ADVISORY FOR AKZ213-AKZ214-AKZ215-AKZ216-AKZ220- AKZ221-AKZ222-AKZ227. GALE WARNING FOR PKZ210. BRISK WIND ADVISORY FOR PKZ200-PKZ215-PKZ220. && $$ TF MAR 12 ______________________________________________________________________ PAFG - Reference: ['this mornings polar orbiting satellite imagery shows an area of'] 961 FXAK69 PAFG 061430 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 530 AM AKST TUE MAR 6 2012 .DISCUSSION... THE GFS AND NAM COMPUTER WEATHER FORECAST MODELS ARE FORCASTING A SIGNIFICANT CHANGE. A LARGE COLD LOW ALOFT IS FORECAST TO EXPAND SOUTHWARD OVER THE ALASKA MAINLAND TONIGHT AND WEDNESDAY. THIS WILL CAUSE THE PRESENT BRISK WESTERLY FLOW SOUTH OF THE ARCTIC CIRCLE TO BECOME LIGHTER SOUTHWEST FLOW. THE MODELS HAVE BEEN CONSISTENT ON THIS FORECAST FOR SEVERAL DAYS. A SHORT WAVE ALOFT ON THE LEADING EDGE OF THE COLD LOW ALOFT IS FORECAST TO MOVE SLOWLY SOUTH OVER THE MAINLAND THROUGH WEDNESDAY. WITH THE APPROACH OF THIS TROUGH ALOFT...SNOW OVER SOUTHWEST ALASKA IS EXPECTED TO RESUME TONIGHT. STARTING LATE WEDNESDAY...THE COLD LOW ALOFT IS EXPECTED TO EXPAND AND TO HOLD OVER THE EASTERN MAINLAND THROUGH MID WEEK NEXT WEEK AND QUITE POSSIBLY LONGER. THE INFLUX OF COLD ARCTIC AIR ON THE WEST SIDE OF THE LOW ALOFT IS BRINGING TEMPERATURES IN THE WESTERN MAINLAND DOWN TO SUB ZERO LEVELS...WHERE THEY WILL REMAIN FOR SOME TIME. THE AIR MASS OVER MOST OF THE INTERIOR REMAINS UNSTABLE THIS MORNING. SNOW SHOWERS ARE RAPIDLY MOVING THROUGH IN THE BRISK WESTERLY FLOW ALOFT. NEAR THE 5000 FOOT ELEVATION...THE WINDS ARE FROM THE WEST SOUTHWEST AROUND 40 MPH. THIS IS NOT COMMON IN INTERIOR ALASKA AT ANY TIME OF YEAR. THE FAIRBANKS WEATHER BALLOON RUN THIS MORNING...THE HOURLY DATA FROM THE FAIRBANKS WEATHER RADAR...AND THE PROFILER AT CENTRAL AGREE CLOSELY ON THIS. THE STRENGTH OF THE WINDS ALOFT IS THE REASON FOR THE WINTER WEATHER ADVISORIES OVER THE HIGH LANDS OF THE SOUTHERN INTERIOR. AS THE COLD LOW ALOFT BECOMES ESTABLISHED OVER THE WESTERN MAINLAND...THE WINDS ALOFT OVER THE SOUTHERN INTERIOR WILL DIMINISH. THIS MORNINGS POLAR ORBITING SATELLITE IMAGERY SHOWS AN AREA OF SNOW SHOWERS THAT LOOKS PARTICULARLY ACTIVE. AT 3 AM THIS MORNING...THIS CLUSTER OF SNOW SHOWERS WAS JUST EAST OF GALENA. THE CLUSTER IS ABOUT 100 MILES IN DIAMETER. IF IT MOVES TOWARD THE EAST AT 40 MPH...IT WILL BE OVER NENANA AND FAIRBANKS JUST BEFORE SUNRISE. SUNRISE AT FAIRBANKS TODAY IS AT 7.41 AM AKST. OUT OVER THE BERING SEA THERE ARE SCATTERED SNOW SHOWERS MOVING TOWARD THE EAST. CONTINUING ON THEIR PRESENT COURSE THE WILL REMAIN SOUTH OF THE YUKON DELTA. THE COLDEST TEMPERATURES IN THE REALM THIS MORNING ARE ON THE ARCTIC COASTAL PLAIN...THE ONLY PART OF NORTHERN ALASKA THAT HAS CLEAR SKIES. THE INFRARED DERIVED TEMPERATURES THERE ARE AROUND 45 BELOW. && .AFG WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FOR AKZ220-AKZ221-AKZ222-AKZ227. BRISK WIND ADVISORY FOR PKZ210. && $$ TF MAR 12 ______________________________________________________________________ PAFG - Reference: ['this mornings polar orbiting satellite imagery show a well defined'] 569 FXAK69 PAFG 071501 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 601 AM AKST WED MAR 7 2012 .DISCUSSION... THE GFS AND NAM COMPUTER WEATHER FORECAST MODELS CONTINUE TO PREDICT CONSIDERABLY LESS ENERGETIC WEATHER...STARTING TODAY. THE REMAINS OF THE SURFACE LOW PRESSURE SYSTEM THAT MOVED INTO THE WESTERN ALEUTIANS OVER THE WEEKEND / LOW NUMBER 1 / ARE NOW ABOUT 100 MILES OFFSHORE KUSKOKWIM BAY...AND MOVING TOWARD THE SOUTHEAST. THE LOW HAS WEAKENED CONSIDERABLY. THE EVENING RUNS OF THE GFS AND NAM MODELS DIFFERED SIGNIFICANTLY...TO AN UNUSUALLY LARGE EXTENT. THE NEW NAM MODEL RUN IS CLOSER TO YESTERDAYS GFS. BOTH HAVE REASONABLE FORECASTS OF THE PATH A FAIRLY STRONG SURFACE LOW / LOW NUMBER 2 / NOW JUST OF THE SOUTHERN END OF THE KAMCHATKA. AS EARLIER MODEL RUNS HAD FORECAST...THE MODELS PREDICT THIS NEW PACIFIC LOW TO REACH THE WESTERN ALEUTIANS THIS EVENING...AND THEN TO TURN EASTWARD TO CROSS THE WEST END OF THE ALASKA PENINSULA ON THURSDAY. THE WEST PACIFIC SATELLITE IMAGERY PRESENTS LOW NUMBER 2 NOT AS STRONG AS THE MODELS FORECAST THE LOW TO BE...BUT THIS APPARENT DIFFERENCE IS PROBABLY NOT TOO IMPORTANT. WHAT MATTERS IN THIS ASPECT IS THAT THE YUKON DELTA AND SAINT LAWRENCE ISLAND WILL BE OUT OF THE REACH OF LOW NUMBER 2. THE NEW FEATURE IN THE FORECASTS TODAY IS / LOW NUMBER 3 /. LOW NUMBER 3 IS CLOSE TO 40 DEGREES NORTH LATITUDE...ROUGHLY 1500 MILES SOUTH OF ANCHORAGE. THE CURRENT MODEL RUNS FORECAST LOW NUMBER 3 TO BE FAIRLY STRONG. THE CIRCULATION OF LOW NUMBER 1 WILL MERGE WITH THAT OF LOW NUMBER 3 IN THE EASTERN GULF OF ALASKA ON THURSDAY. THE COMBINED ENERGY OF THESE LOWS...AND THE LARGE AMOUNT OF MOISTURE WITH LOW NUMBER 3...SHOULD BRING SNOW TO THE EASTERN INTERIOR ON THURSDAY AND FRIDAY. THIS SNOWFALL COULD BE SIGNIFICANT. NORTHEAST GULF OF ALASKA LOWS CAN BRING SNOW ACCUMULATIONS OF 4 TO 8 INCHES OVER 24 HOURS TO THE FORTYMILE COUNTRY. LOW NUMBER 3 MIGHT DO THIS. THE ACCUMULATIONS IN THIS EVENT WILL NOT BE AS GREAT AS THE 10 TO 20 INCHES OF SNOW THAT FELL IN THE MIDDLE TANANA VALLEY OVER THE PAST TWO DAYS. IT SHOULD BE NOTED THAT LOW NUMBER 3 IS ..NOT.. GOING TO BE A SO CALLED PINEAPPLE EXPRESS...WHICH BRINGS VERY WARM CHINOOKS INTO THE INTERIOR. THE PATH OF LOW NUMBER 3 IS TOO FAR EAST TO DO THIS. THE MODELS CONTINUE TO FORECAST A LARGE COLD LOW ALOFT TO SETTLE OVER THE ALASKA MAINLAND STARTING THURSDAY. TEMPERATURES ARE EXPECTED TO DROP NEARLY EVERYWHERE IN THE REALM...BUT NOT TO A GREAT EXTENT. LOW TEMPERATURES SHOULD BE IN THE 20 TO 30 BELOW RANGE. THE GFS MODEL FORECASTS THE COLD LOW ALOFT TO REMAIN OVER THE MAINLAND FOR ALL OF NEXT WEEK. THIS MORNINGS POLAR ORBITING SATELLITE IMAGERY SHOW A WELL DEFINED NORTHERN EDGE OF THE CLOUDS. THIS EDGE PRESENTLY EXTENDS FROM JUST SOUTH OF FORT YUKON...TO JUST SOUTH OF BETTLES...TO JUST SOUTH OF KOYUK...AND JUST NORTH OF THE YUKON DELTA. ASIDE FROM SOME RATHER SMALL AND DISORGANIZED STRATOCUMULUS CLOUD DECKS OVER THE ARCTIC SLOPE...SKIES ARE CLEAR NORTH OF THE CLOUD EDGE. BRISK WEST SOUTHWEST FLOW ALOFT PERSISTED ALONG AND TO THE SOUTH OF THE CLOUD EDGE FOR TWO DAYS...AND WAS ESPECIALLY STRONG YESTERDAY / TUESDAY /. THIS FLOW PATTERN CAN BRING IN SIGNIFICANT SNOWFALL TO INTERIOR ALASKA. THE SNOWFALL FROM THIS EPISODE WAS CERTAINLY MORE THAN IN MOST SUCH WEST SOUTHWESTERS. THE WINDS ALOFT AS MEASURED BY THE FAIRBANKS WEATHER BALLOON DATA...THE PROFILER AT CENTRAL...AND THE FAIRBANKS WEATHER RADAR...ALL REMAIN BRISK WESTERLY. THE MODELS FORECAST THESE WINDS ALOFT TO WEAKEN SIGNIFICANTLY TODAY. HENCE THE STRONG HIGHLAND WINDS IN THE FAIRBANKS AND FORT YUKON ZONES ARE EXPECTED TO DECREASE TODAY. THE AIR MASS OVER MUCH THE SOUTHEASTERN INTERIOR REMAINS UNSTABLE...AS IT HAS BEEN SINCE MONDAY. SNOW ACCUMULATIONS HAVE BEEN VERY UNEVEN...AS CAN BE EXPECTED WITH A LONG SNOW SHOWER EVENT. THE BARTHEL RADAR SHOWS YET ANOTHER CLUSTER OF CUMULUS SNOW SHOWER CLOUDS MOVING IN FROM THE SOUTHWEST. THE YUKON DELTA IS EXPECTED TO CATCH SOME OF THIS SNOW TODAY. && .AFG WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY FOR AKZ203-AKZ204. WINTER STORM WARNING FOR AKZ222. WINTER WEATHER ADVISORY FOR AKZ220. BRISK WIND ADVISORY FOR PKZ210. && $$ TF MAR 12 ______________________________________________________________________ PAFG - Reference: ['early afternoon polar orbiting satellite imagery shows lingering'] 690 FXAK69 PAFG 122325 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 325 PM AKDT MON MAR 12 2012 .DISCUSSION... THE GFS AND NAM COMPUTER WEATHER FORECAST MODELS ARE IN SYNC. A COLD TROUGH ALOFT NOW EXTENDS FROM BARTER ISLAND TO A CLOSED LOW NEAR MCGRATH. THE NAM AND GFS FORECAST THE MCGRATH LOW TO MOVE SOUTHWEST TO BETHEL BY WEDNESDAY MORNING...AND TO CONTINUE DRIFTING SOUTHWARD THROUGH FRIDAY. THE NORTH PORTION OF THE TROUGH ALOFT WILL REMAIN OVER BARTER ISLAND. COLD NORTHEAST FLOW ALOFT WILL STRENGTHEN SOME OVER THE ARCTIC AND WESTERN COASTAL REGIONS OF THE REALM. IN TANDEM WITH THIS...COASTAL REGION NORTH WINDS WILL INCREASE SOME...AND MEET BRISK WIND ADVISORY CRITERIA FOR THE REST OF THIS WEEK. THE GFS MODEL FORECASTS THE TROUGH ALOFT TO SHIFT TO AN AXIS FROM PRUDHOE BAY TO KODIAK EARLY NEXT WEEK. A LARGE RIDGE OF HIGH PRESSURE ALOFT OVER THE RUSSIAN FAR EAST WILL BUILD OVER THE BERING SEA THROUGH NEXT WEDNESDAY. THIS PATTERN IS QUITE A STABLE ONE...AND WILL KEEP TEMPERATURES NEAR OR BELOW NORMAL. THERE WILL BE VERY LITTLE PRECIPITATION IN THE REALM UNTIL THE PATTERN CHANGES. THAT WILL TAKE AT LEAST 10 DAYS. TO THE EAST OF THE TROUGH ALOFT...WEAK SOUTHERLY FLOW ALOFT IS EXPECTED TO BRING EASTERN INTERIOR TEMPERATURES UP A LITTLE LATER THIS WEEK. A 967 MB LOW NOW 250 MILES NORTH OF AMCHITKA ISLAND HAS BEEN WELL FORECAST BY THE MODELS. IT IS NOW WEAKENING AND HEADED EASTWARD...AND IS FORECAST TO MOVE PAST DUTCH HARBOR EARLY TUESDAY AFTERNOON. OTHER THAN BRINGING A LITTLE ENERGY TO THE NORTHERLY SURFACE WINDS TO THE CHUKCHI AND BERING SEA COASTAL REGIONS THIS SYSTEM WILL HAVE VERY LITTLE EFFECT IN NORTHERN ALASKA. THE LARGE BODY OF ARCTIC AIR IN THE TROUGH ALOFT OVER ALASKA WILL ACT AS AN EFFECTIVE BARRIER TO PACIFIC LOW PRESSURE SYSTEMS. ONCE THE LOW NOW IN THE SOUTHERN BERING SEA PASSES EASTWARD...THE NORTH PACIFIC STORM TRACK WILL BE FAR TO THE SOUTH OF THE ALASKA MAINLAND. OVERALL...ALL ASPECTS OF CIRCULATION OVER ALASKA AND THE BERING SEA ARE VERY STABLE. RATHER COOL SPRING WEATHER LOOKS LIKE IT WILL CONTINUE FOR SOME TIME. ASIDE FROM PERSISTENT LOW CLOUDS AND FLURRIES OVER THE ARCTIC SLOPE...SAINT LAWRENCE ISLAND AND BERING STRAIT...THE WEATHER OVER NORTHERN ALASKA WILL BE CLEAR IN THE WEST AND PARTLY CLOUDY OVER THE SOUTHEASTERN INTERIOR FOR SOME TIME. EARLY AFTERNOON POLAR ORBITING SATELLITE IMAGERY SHOWS LINGERING LOW CLOUDS OVER THE ARCTIC COAST AND PART OF THE INLAND COASTAL PLAIN...AND ALSO OVER SAINT LAWRENCE ISLAND AND BERING STRAIT. THE EXTENT OF THE LOW CLOUDS OVER THE ARCTIC SLOPE HAS DECREASED SOME IN THE PAST 24 HOURS. THE SOUTHEASTERN INTERIOR REMAINS MOSTLY CLOUDY. && .AFG WATCHES/WARNINGS/ADVISORIES... BRISK WIND ADVISORY FOR PKZ210-PKZ220-PKZ225. && $$ TF MAR 12 ______________________________________________________________________ PAFG - Reference: ['this mornings polar orbiting satellite imagery shows stratocumulus'] 932 FXAK69 PAFG 271252 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 452 AM AKDT TUE MAR 27 2012 .DISCUSSION... TODAYS WEATHER PATTERN IN NORTHERN ALASKA IS MOSTLY QUIET AND BENIGN. ONLY THE NORTHWEST COASTAL ZONES...WHICH ARE CONTINUING TO HAVE LOW WIND CHILLS...AND THE BRISK WINDS IN THE NORTHWEST MARINE AREAS...ARE OF NOTE. IN BERING STRAIT...THE WINDS AT TIN CITY ARE GUSTING TO 40 MPH. THE STRONGEST WINDS WILL CONTINUE TO BE FOCUSED THERE. THE WEAKENING LOW PRESSURE SYSTEM NOW JUST EAST OF THE PRIBILOFS HAS BECOME NEARLY STATIONARY. SOME ENERGY IS MOVING NORTHWARD TO THE BERING SEA COAST OF NORTHERN ALASKA. THIS IS EXPECTED TO INCREASE THE WINDS THERE TODAY AND TONIGHT. THE WINDS OVER NORTON SOUND ARE EXPECTED TO DIMINISH WEDNESDAY AS THE CIRCULATION AROUND THE PRIBILOF ISLANDS LOW IS TRANSFERRED NORTHWARD TO THE CHUKCHI SEA COAST. THERE WILL PROBABLY BE SOME LOCALLY GUSTY WINDS IN CHANNELED AREAS OF THE CENTRAL AND WESTERN BROOKS RANGE STARTING THIS EVENING AND CONTINUING INTO WEDNESDAY EVENING. THE GFS AND NAM COMPUTER WEATHER FORECAST MODELS HAVE SIMILAR PROJECTIONS THROUGH THURSDAY MORNING. THE PRIBILOF ISLANDS LOW IS FORECAST TO REMAIN PRETTY CLOSE TO THE ISLANDS UNTIL WEDNESDAY EVENING...AT WHICH TIME IT IS EXPECTED TO HEAD INTO THE GULF OF ALASKA. BRISK NORTH WINDS ON THE BACK SIDE OF THE LOW WILL CONTINUE BLOWING OVER THE COASTAL WATERS FROM CAPE LISBURNE DOWN PAST SAINT LAWRENCE ISLAND FOR THE REST OF THIS WEEK. ALL OF THE COMPUTER WEATHER FORECAST MODELS FORECAST THE NORTH PACIFIC STORM TRACK TO REMAIN WELL BELOW 55 DEGREES NORTH LATITUDE FOR THE REST OF THIS WEEK. FOR THIS COMING SUNDAY NIGHT / APRIL 1 - 2 / THE GFS MODEL FORECASTS A LARGE LOW TO MOVE NORTHWARD FROM THE PACIFIC TO THE GULF OF ALASKA. THE EUROPEAN MODEL FORECASTS ONLY WEAK CIRCULATION OVER THE GULF OF ALASKA NEXT WEEK. THE BEST GUESS WOULD BE TO SPLIT THE DIFFERENCE BETWEEN THE MODELS...NEITHER ONE LOOKS REASONABLE FOR THE FORECAST FOR NEXT WEEK. AN AREA OF HIGH PRESSURE ALOFT IS BUILDING OVER THE EASTERN GULF OF ALASKA AND IS EXPECTED TO BUILD UP OVER THE YUKON TERRITORY AND NORTHERN ALASKA THROUGH WEDNESDAY NIGHT...AND TO HOLD THERE FOR THE REST OF THE WEEK. THE GFS MODEL FORECASTS THE HIGH PRESSURE TO RECEDE INTO NORTHWEST CANADA AND TO BE REPLACED BY WEAK LOW PRESSURE ALOFT OVER THE ALASKA MAINLAND ON SUNDAY. THE GFS THEN FORECASTS THE NORTHWEST CANADA HIGH ALOFT TO REBUILD OVER THE YUKON AND THE ALASKA INTERIOR. THE UPSHOT OF THIS IS THAT THERE WILL NOT BE MUCH PRECIPITATION OUTSIDE OF THE NORTON SOUND COASTAL ZONES...AND ONLY SOME IN THOSE ZONES. THE BEST BET FOR SNOW FOR THE NEXT 36 HOURS IS THE EAST SIDE OF THE NULATO HILLS...WHICH WILL BENEFIT FROM EASTERLY UP SLOPE FLOW. TEMPERATURES WILL CONTINUE TO GRADUALLY MODERATE. THE CENTRAL AND EASTERN INTERIOR...AS WELL AS THE ARCTIC...WILL HAVE VERY LITTLE IF ANY PRECIPITATION FOR THE REMAINDER OF THIS WEEK. THIS MORNINGS POLAR ORBITING SATELLITE IMAGERY SHOWS STRATOCUMULUS EXITING THE BROOKS RANGE EAST OF ARCTIC VILLAGE...AND A SMALL DECK OF STRATOCUMULUS OVER THE YUKON FLATS / IT CLEARED OUT AT FORT YUKON JUST BEFORE 3 AM AKDT. / LAYERED FRONTAL CLOUDS AHEAD OF THE PRIBILOF ISLAND LOW OCCLUDED FRONT ARE ADVANCING NORTHWARD...AND COVER ALL OF THE LOWER YUKON VALLEY...THE YUKON DELTA...AND A GOOD PART OF NORTON SOUND. INFRARED SATELLITE DERIVED SURFACE TEMPERATURES IN THE CENTRAL BROOKS RANGE ARE FROM -40C TO -45C. ON THE ARCTIC COASTAL PLAIN THE TEMPERATURES ARE FROM -35C TO -40C. && .AFG WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY FOR AKZ213. WIND CHILL WARNING FOR AKZ201. BRISK WIND ADVISORY FOR PKZ210-PKZ220-PKZ225-PKZ230. && $$ TF MAR 12 ______________________________________________________________________ PAFG - Reference: ['polar orbiting satellite imagery shows mostly clear skies over the'] 099 FXAK69 PAFG 281300 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 500 AM AKDT WED MAR 28 2012 .DISCUSSION... THE LOW CENTERED JUST EAST OF THE PRIBILOF ISLANDS HAS HARDLY MOVED DURING THE PAST 24 HOURS -- AS EXPECTED. THE STRENGTH OF THE LOW INCREASED SOME ON TUESDAY AND HENCE THE NORTHERLY GALES DEVELOPED ON THE NORTHWEST COAST YESTERDAY AFTERNOON. THE LOW HAS BEEN GRADUALLY WEAKENING SINCE YESTERDAY /TUESDAY / EVENING. THE OCCLUDED FRONT AHEAD OF THE PRIBILOF ISLAND LOW HAS BROUGHT SOME SNOW TO THE LOWER YUKON VALLEY...THE MIDDLE YUKON VALLEY...THE YUKON DELTA...THE NORTON SOUND COAST AND THE SEWARD PENINSULA. THE SNOWFALL AMOUNTS HAVE BEEN LIGHT...ONLY AN INCH OF SNOW IS EXPECTED ON THE SOUTHERN SEWARD PENINSULA TODAY. AS THE OCCLUSION WEAKENS TONIGHT THE SNOW IN THE WEST WILL END. PERSISTENT HIGH PRESSURE OVER CHUKOTKA AND A PERSISTENT TROUGH OF LOW PRESSURE EXTENDING FROM THE YUKON DELTA TO THE SEWARD PENINSULA WILL MAINTAIN BRISK NORTH/NORTHEAST WINDS FROM CAPE LISBURNE DOWN OVER THE CHUKCHI SEA COAST AND THE WESTERN SEWARD PENINSULA FOR SOME TIME...PROBABLY THROUGH THE END OF THIS WEEK. THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS HAVE SIMILAR PROJECTIONS WHICH ARE CONSISTENT WITH THE OUTPUT FROM YESTERDAYS RUNS. BOTH MODELS FORECAST THE PRIBILOF ISLAND LOW TO CONTINUE WEAKENING AND TO MOVE EASTWARD ACROSS THE ALASKA PENINSULA INTO THE GULF OF ALASKA TONIGHT. ALSO...BOTH MODELS FORECAST HIGH PRESSURE ALOFT OVER THE EASTERN GULF OF ALASKA AND THE SOUTHEASTERN MAINLAND OF ALASKA TO BUILD INTO THE ALASKAN INTERIOR TODAY AND TONIGHT...AND TO SHIFT NORTHWARD OVER THE NORTHERN INTERIOR AND THE BROOKS RANGE THURSDAY AND THURSDAY NIGHT. CIRCULATION ALOFT AROUND THIS FEATURE WILL BECOME VERY WEAK TONIGHT AND THURSDAY...AND WILL REMAIN SO THROUGH THIS FRIDAY. A LARGE LOW PRESSURE SYSTEM ALOFT NORTH OF ALASKA...NEAR 80 DEGREES NORTH LATITUDE...IS EXPECTED TO EXPAND SOUTHWARD TO THE ALASKA ARCTIC COAST FRIDAY AND SATURDAY. ON SATURDAY NIGHT...THE GFS MODEL FORECASTS A STRONG TROUGH ALOFT TO MOVE SOUTHWARD OVER THE ALASKAN ARCTIC AND THE BROOKS RANGE. THIS COULD BRING SNOW TO MUCH OF THE ALASKAN ARCTIC OVER THIS WEEKEND. THE GFS AND EUROPEAN MODELS DIVERGE SIGNIFICANTLY STARTING THIS WEEKEND...THE EUROPEAN MODEL FORECASTS A MUCH STRONGER LOW ALOFT TO ADVANCE SOUTHWARD TO THE SEWARD PENINSULA SATURDAY NIGHT. THE MODELS DIVERGE EVEN FURTHER IN THE PROJECTIONS FOR NEXT WEEK. THE AMOUNT OF UNCERTAINTY IN THE FORECASTS STARTING WITH THIS SATURDAY IS DEFINITELY GREATER THAN USUAL. HOWEVER...THE GFS AND EUROPEAN MODEL FORECASTS FOR THE END OF NEXT WEEK INDICATE HIGH PRESSURE ALOFT BUILDING OVER THE EASTERN BERING SEA. IF THIS IS CLOSE TO THE REAL OUTCOME...MUCH OF THE REALM WILL HAVE MOSTLY SUNNY WEATHER AND RISING TEMPERATURES IN THE SECOND HALF OF NEXT WEEK. THIS MORNINGS GEOSTATIONARY SATELLITE IMAGERY SHOWS THE NORTH PACIFIC STORM TRACK FAR TO THE SOUTH OF THE ALASKA MAINLAND. THE POLAR ORBITING SATELLITE IMAGERY SHOWS MOSTLY CLEAR SKIES OVER THE EASTERN INTERIOR...THE EASTERN BROOKS RANGE...AND THE ARCTIC SLOPE. LAYERED FRONTAL CLOUDS COVER THE WEST HALF OF THE INTERIOR. LOWER LAYERED CLOUDS -- TO THE WEST OF THE OCCLUDED FRONT -- COVER THE BERING AND CHUKCHI SEA COASTS. THE MAJOR LEADS IN THE CHUKCHI SEA ICE OFFSHORE THE WESTERN ARCTIC COAST HAVE GOOD DEFINITION AND HAVE BEEN EASY TO FOLLOW AS THEY MOVE. THE BRISK NORTHEAST WINDS HAVE MOVED THE ICE SOUTHWESTWARD ABOUT 15 MILES IN THE PAST 24 HOURS. && .AFG WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY FOR AKZ213. WIND CHILL WARNING FOR AKZ201. GALE WARNING FOR PKZ210-PKZ225. BRISK WIND ADVISORY FOR PKZ200-PKZ220-PKZ230. && $$ TF MAR 12 ______________________________________________________________________ PAFG - Reference: ['this mornings polar orbiting satellite imagery shows layered'] 580 FXAK69 PAFG 121342 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 542 AM AKDT SAT MAY 12 2012 .DISCUSSION... THE WEATHER MAPS THIS MORNING ARE TYPICAL OF EARLY SUMMER...A PATTERN ANY EXPERIENCED ANALYST HAS SEEN HUNDREDS OF TIMES BEFORE. CIRCULATION OVER THE REALM IS WEAK AND FORECAST BY THE COMPUTER MODELS TO REMAIN SO THROUGH NEXT WEEK. THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS FORECAST A COLD LOW PRESSURE SYSTEM ALOFT TO MOVE SOUTH SOUTHEASTWARD...AND TO REACH KODIAK ISLAND SUNDAY MORNING. A TROUGH OF LOW PRESSURE WILL REMAIN EXTENDING FROM THE LOW ALOFT TO THE SOUTHERN CHUKCHI SEA THROUGH EARLY MONDAY. FOLLOWING THIS...HIGH PRESSURE ALOFT WILL GRADUALLY AND STEADILY BUILD OVER THE EASTERN BERING SEA STARTING LATE MONDAY. BY WEDNESDAY NIGHT...THE HIGH PRESSURE ALOFT WILL COVER THE WEST HALF OF THE REALM AND HOLD THERE. THE FRIDAY EVENING GFS MODEL RUN DIFFERS FROM THE FRIDAY AFTERNOON FORECASTS OF THE GFS AND EUROPEAN MODELS. THE FRIDAY AFTERNOON RUNS FORECAST THE HIGH PRESSURE ALOFT TO BUILD OVER ALL BUT THE EASTERNMOST PART OF THE REALM...WITH VERY WEAK CIRCULATION. THIS IS A PATTERN TYPICAL OF EARLY SUMMER IN ALASKA. THE FRIDAY EVENING GFS MODEL RUN FORECASTS NORTH FLOW ALOFT OVER THE EASTERN HALF OF NORTHERN ALASKA STARTING WEDNESDAY...AND TO CHANGE TO NORTHEASTERLY FLOW WITH A SERIES OF SMALL DISTURBANCES MOVING ALONG WITH IT. THE INTERMEDIATE GFS MODEL RUNS VERY OFTEN TAKE EXCURSIONS OFF THE PREVIOUS MODEL RUNS COURSE...SO THE PREVIOUS AFTERNOONS MODEL RUN IS OFTEN FAVORED OVER THE RUN 6 HOURS LATER.L THE UPSHOT IS THAT AN OUTBREAK OF MOSTLY CLOUDY...COOLER AND SHOWERY WEATHER IS NOT IN THIS MORNINGS FORECASTS FOR THE EASTERN OR CENTRAL INTERIOR. A SMALL TROUGH OF LOW SURFACE PRESSURE IS FORMING IN THE EASTERN BROOKS RANGE AND IS EXPECTED TO SHIFT TO THE SOUTHERN BEAUFORT SEA JUST NORTH OF THE ARCTIC COAST OF THE YUKON TERRITORY TONIGHT. THIS PROCESS OCCURS OFTEN IN THE SOUTHEAST BERING SEA AND CAN BE FORECAST WITH CONFIDENCE...AS IT IS TODAY. THE REASON THIS IS OF INTEREST TO THE FORECASTS IS THAT IT CAUSES THE EAST WINDS OVER THE ALASKAN ARCTIC COAST FROM PRUDHOE BAY EASTWARD TO SHIFT TO THE WEST. THIS MORNINGS FORECASTS FOR THAT AREA ARE FOR EAST WINDS TODAY AND TONIGHT...AND WEST WINDS MONDAY AND BEYOND. THIS MORNINGS WEATHER BALLOON DATA INDICATES UNSTABLE AIR OVER THE EAST HALF OF NORTHERN ALASKA. SOME SHOWERS...AND ISOLATED THUNDERSTORMS...ARE EXPECTED. THE ALASKA LIGHTNING DETECTION SYSTEM RECORDED 40 LIGHTNING STRIKES FRIDAY AFTERNOON AND EVENING, THIS WAS THE LARGEST DAILY TOTAL OF LIGHTNING STRIKES FOR THE YEAR SO FAR. MOST OF THE STRIKES WERE BETWEEN BETTLES AND GALENA...AND THE REST WERE AROUND MCGRATH. THE AMOUNT OF MOISTURE IN THE AIR MASS OVER NORTHERN ALASKA THIS MORNING IS SCANTY...FROM 0.25 TO 0.35 INCH...SO STRONG THUNDERSTORMS ARE IMPOSSIBLE. THIS IS TYPICAL OF MAY...THE MONTH OF THE YEAR IN NORTHERN ALASKA WHEN AFTERNOON RELATIVE HUMIDITY IS TYPICALLY LOWER THAN IN THE REST OF THE YEAR. THE NAM AND GFS MODELS FORECAST AN AXIS OF HIGH PRESSURE NOW OVER THE NORTH GULF COAST TO BUILD NORTHWARD TOWARD THE ALASKA RANGE. THIS IS A GOOD PATTERN FOR BRISK GAP WINDS IN THE AFTERNOON AND EVENING...SO THE FORECASTS FOR THE ALASKA RANGE AND THE DELTANA AND TANANA FLATS INCLUDE GUSTY WINDS FOR THOSE AREAS THIS AFTERNOON AND EVENING. THIS MORNINGS POLAR ORBITING SATELLITE IMAGERY SHOWS LAYERED CIRRUS AND ALTOSTRATUS CLOUDS STREAMING OFF THE WESTERN ALASKA RANGE INTO THE UPPER KUSKOKWIM AND MIDDLE YUKON VALLEYS. SKIES ARE MOSTLY CLOUDY TO THE WEST. THERE ARE CONVECTIVE DEBRIS OVER THE WESTERN INTERIOR...AND LOW STRATUS OVERCAST OVER THE WEST COASTAL REGIONS. THE EASTERN INTERIOR IS MOSTLY CLEAR. && .FIRE WEATHER... GUSTY WINDS OUT OF ALASKA RANGE PASSES WILL REACH SOME VALLEY FLOORS IN THE SOUTHERN INTERIOR THIS AFTERNOON AND EVENING. THESE...AND LATE AFTERNOON RELATIVE HUMIDITY BETWEEN 20 TO 30 PERCENT IN PLACES...ARE TO BE WATCHED WITH CARE. THE WIND THIS AFTERNOON IS NOT EXPECTED TO BE AS STRONG AS YESTERDAY. && .HYDROLOGY... ASIDE FROM THE FLOODING AT MANLEY HOT SPRINGS TWO WEEKS AGO...THE 2012 NORTHERN ALASKA BREAKUP ON RIVERS HAS BEEN THE MOST QUIET IN AT LEAST 40 YEARS. THANKS TO A GRADUAL AND MODEST WARMING STARTING IN APRIL...THE SNOWMELT WAS STRETCHED OUT OVER ENOUGH TIME TO KEEP RIVERS AT MODEST STAGES. THE LOWER YUKON VALLEY DOES HAVE SOME ICE JAMS BUT SO FAR THERE HAS BEEN NO HIGH WATER WITH THEM. BREAKUP IN THE UPPER KUSKOKWIM VALLEY IS ABOUT OVER. && .AFG WATCHES/WARNINGS/ADVISORIES... NONE. && $$ TF MAY 12 ______________________________________________________________________ PAFG - Reference: ['polar orbiting satellite imagery indicates that the weather system'] 528 FXAK69 PAFG 180007 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 407 PM AKDT THU MAY 17 2012 .DISCUSSION... THE NAM AND GSM COMPUTER WEATHER FORECAST MODELS DIFFER SOME IN THE CHUKCHI SEA FORECASTS. THIS MORNINGS / 10 AM ALASKA TIME / GSM MODEL RUN FORECASTS A LOW ALOFT TO MOVE FROM THE NORTHWEST CHUKCHI SEA TO THE WESTERN ALASKA ARCTIC COAST ON SATURDAY. AS IS OFTEN THE CASE...THE 10 AM GSM MODEL RUN HAS DIFFERENCES FROM THE EARLY MORNING / 4 AM ALASKA TIME / RUN. USUALLY...THE GSM 10 AM / AND THE 10 PM / RUN DO NOT IMPROVE THE FORECAST. THE NAM MODEL FORECASTS THIS LOW TO MOVE ON A TRACK FARTHER UP IN THE ARCTIC...IN A MANNER THAT IT WOULD HAVE LESS IMPACT ON THE ALASKAN ARCTIC THAN THE OUTCOME IN THE GSM MODEL PROJECTIONS. HIGH PRESSURE ALOFT NOW OVER THE ALASKA MAINLAND IS FORECAST TO GRADUALLY SHIFT WESTWARD TO CHUKOTKA ON FRIDAY. LOW ALOFT NOW IN THE NORTHWEST CHUKCHI SEA WILL MOVE EAST...A TROUGH OF LOW PRESSURE EXTENDING SOUTHWARD FROM THE LOW WILL REACH THE WESTERN ALASKAN ARCTIC ON FRIDAY...AND WEAKEN AS IT MOVES EASTWARD TO REACH BARROW ON SATURDAY. THIS IS EXPECTED TO BRING SOME SNOW TO THE WESTERN ARCTIC COASTAL AREA...BUT NOT VERY MUCH. THE AFTERNOON POLAR ORBITING SATELLITE IMAGERY INDICATES THAT THE WEATHER SYSTEM IN THE WEST CHUKCHI SEA IS NOT VERY STRONG. FOR THE REST OF THE UPCOMING WEEK...AN AXIS OF HIGH PRESSURE ALOFT IS EXPECTED TO EXTEND FROM THE YUKON...OVER INTERIOR ALASKA...TO THE GULF OF ANADYR. THIS FAVORS SUNNY...WARMER...AND DEFINITELY DRY WEATHER IN THE INTERIOR. THE WEST COAST WILL BE CLOUDY WHEN WINDS ARE ONSHORE. FOR NOW...WINDS ON THE ALASKA WEST COAST ARE SHIFTING FROM EAST TO NORTHEAST. THUS...ASIDE FROM THE NORTHWEST SEWARD PENINSULA...CLOUDS OUT THERE ARE EXPECTED TO DECREASE FRIDAY. ON SATURDAY...SOUTHWEST WINDS ARE FORECAST TO BRING MORE CLOUD COVER TO THE COAST FROM CAPE KRUSENSTERN / WEST OF KOTZEBUE / TO POINT HOPE. THIS AFTERNOONS SATELLITE IMAGERY SHOWS CLOUDY WEATHER FROM THE SEWARD PENINSULA OVER THE CHUKCHI SEA...THE NOATAK VALLEY...AND THE ALASKAN ARCTIC INCLUDING THE BROOKS RANGE. CLOUDS HAVE BEEN CLEARING OVER NORTON SOUND. MUCH OF THE INTERIOR IS CLEAR. THE FORTYMILE COUNTRY / THE SOUTHEASTERN INTERIOR / IS PARTLY CLOUDY. THE AIR MASS IS TOO DRY FOR REAL CONVECTIVE DEVELOPMENT...SO THERE ARE NO THUNDERSTORMS FORECAST FOR THIS EVENING OR FOR FRIDAY. && .FIRE WEATHER...THE MEDIUM RANGE FORECAST MODELS PROJECT THE HIGH PRESSURE ALOFT TO HOLD OVER INTERIOR ALASKA FOR MOST OF THE NEXT NINE DAYS. THUS...THE MOST IMPORTANT PART OF THE FORECASTS IS NOW FOR FIRE WEATHER. LATE AFTERNOON RELATIVE HUMIDITY HAS BEEN DROPPING BELOW 20 PERCENT IN SOME PARTS OF THE INTERIOR...AND THIS EFFECT MAY BECOME MORE WIDESPREAD IN THE NEXT SEVERAL DAYS. && .HYDROLOGY...THE 2012 BREAKUP CONTINUES TO BE VERY GENTLE. SOME ICE JAMS ARE BRINGING UP WATER LEVELS AT MARSHALL AND SAINT MARYS / ON THE LOWER YUKON RIVER /. WHEN TEMPERATURES WARM OVER THE NOATAK VALLEY AND THE SEWARD PENINSULA...WATERCOURSES SUCH AS THE BUCKLAND RIVER WILL BEGIN BREAKUP. && .AFG WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FOR AKZ221-AKZ222-AKZ223-AKZ226. FLOOD WATCH FOR AKZ215. && $$ TF MAY 12 ______________________________________________________________________ PAFG - Reference: ['this mornings polar orbiting satellite imagery shows cloud cover'] 748 FXAK69 PAFG 051330 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 530 AM AKDT TUE JUN 5 2012 .DISCUSSION... HIGH PRESSURE ALOFT COVERS THE NORTHEAST MAINLAND THIS MORNING. THE GFS AND NAM COMPUTER WEATHER FORECAST MODELS PREDICT THIS AREA OF HIGH PRESSURE TO EXPAND WESTWARD TODAY AND TONIGHT...AND TO COVER ALL OF THE REALM NORTH OF THE ARCTIC CIRCLE ON WEDNESDAY. TEMPERATURES AT 850 MILLIBARS / ABOUT 5000 FEET ABOVE SEA LEVEL / ARE FORECAST TO COME UP FROM ABOUT 8 DEGREES CELSIUS TODAY TO 10 DEGREES CELSIUS ON WEDNESDAY...AND AS MUCH AS 12 DEGREES CELSIUS ON THURSDAY. SINCE MID SUMMER TEMPERATURES AT 850 MILLIBARS OVER INTERIOR ALASKA CAN REACH 20 DEGREES CELSIUS...THE HIGH TEMPERATURES IN THIS MORNINGS INTERIOR FORECASTS GO ONLY AS FAR AS THE LOWER 80S. ON FRIDAY...THE TEMPERATURES AT THIS LEVEL ARE FORECAST TO REACH AS FAR AS 16 DEGREES CELSIUS...BUT NO FURTHER FOR THE WEEKEND THROUGH NEXT WEEK. THE HIGH PRESSURE ALOFT IS EXPECTED TO HOLD OVER THE REALM NORTH OF THE ARCTIC CIRCLE THROUGH FRIDAY NIGHT. THEN...OVER THE WEEKEND COLDER AND MODERATELY STRONG NORTHEAST FLOW ALOFT IS FORECAST TO BRING SIGNIFICANTLY COLDER TEMPERATURES...AND AN INFLUX OF CLOUDS FROM THE ARCTIC...TO THE EAST HALF OF THE REALM STARTING LATE SATURDAY. THIS COOLING TREND SHOULD DEVELOP OVER ALL OF NORTHERN ALASKA BY SUNDAY EVENING...ESPECIALLY IN THE EAST. BY MID WEEK NEXT WEEK...THE INFLOW OF COLD AIR ALOFT WILL WEAKEN. ALTHOUGH 850 MILLIBAR TEMPERATURES WILL BE DOWN TO 4 TO 6 DEGREES CELSIUS THEN...A RECOVERY OF TEMPERATURES IN NORTHERN ALASKA CAN BE EXPECTED BEGINNING WEDNESDAY...THOUGH IT IS UNLIKELY TO REACH THE WARMTH EXPECTED HERE FOR THE NEXT 3 DAYS. THE ATMOSPHERE OVER INTERIOR ALASKA IS STILL UNSTABLE THIS MORNING. THE BETHEL RADAR SHOWED A REMARKABLE SWATH OF HEAVY RETURNS ON MONDAY EVENING...COVERING ALL OF THE KUSKOKWIM DELTA AND A GOOD PORTION OF THE LOWER YUKON VALLEY. THE ALASKA LIGHTNING DETECTION SYSTEM RECORDED 1429 STRIKES ON MONDAY...THE LARGEST TOTAL FOR THIS SEASON SO FAR. MOST OF THE STRIKES WERE IN THE TROUGH OF THERMAL LOW PRESSURE IN THE INTERIOR...EXTENDING FROM THE LOWER YUKON VALLEY TO THE CENTRAL INTERIOR...THE MIDDLE TANANA VALLEY...AND THE UPLANDS BETWEEN THE YUKON AND TANANA RIVERS. THE NAM20 COMPUTER WEATHER FORECASTING MODEL PROJECTS AN UNSTABLE AIR MASS OVER NEARLY ALL OF THE INTERIOR TODAY...AND THE CENTRAL YUKON VALLEY THIS EVENING. FOLLOWING ITS FORECASTS FROM THE PAST SEVERAL DAYS...THIS MODEL PREDICTS THE UNSTABLE AIR TO SHIFT WESTWARD ON WEDNESDAY...COVERING THE LOWER YUKON VALLEY...THE INTERIOR SEWARD PENINSULA AND THE KOYUKUK AND NOATAK VALLEYS. THE NAM20 MODEL IS A HIGHLY DETAILED MODEL COVERING ALASKA...THE WESTERN MAINLAND OF CANADA...THE GULF OF ALASKA AND BERING SEA AND THE ALASKA AND WESTERN CANADIAN ARCTIC. ITS PREDICTIONS OF SURFACE WIND FLOW AND ATMOSPHERIC STABILITY ARE USUALLY QUITE GOOD. THIS MORNINGS POLAR ORBITING SATELLITE IMAGERY SHOWS CLOUD COVER OVER THE INTERIOR SIMILAR TO MONDAYS...SO THE WEATHER TODAY IS EXPECTED TO BE SIMILAR TO MONDAYS. THE EXCEPTION WILL BE A WESTWARD SHIFT OF THE MOST ACTIVE THUNDER AND LIGHTNING AREA. THIS MORNINGS WEATHER BALLOON RUN AT FAIRBANKS SHOWS A DECREASE IN MOISTURE OVER THE PAST 24 HOURS...FROM A PRECIPITABLE WATER OF 0.87 INCH YESTERDAY TO 0.69 INCH THIS MORNING. THIS IS TO BE EXPECTED NEAR THE AXIS OF EXPANDING HIGH PRESSURE ALOFT. LOW CLOUDS COVER ALL OF THE ARCTIC COAST EAST OF POINT LAY THIS MORNING. THE 15 TO 25 KNOT EASTERLY WINDS ARE ACCOMPANIED BY A WELL MIXED LAYER OF AIR WITHIN A FEW HUNDRED FEET FROM THE SURFACE. THE CLOUD BASES UP THERE NOW ARE FROM 300 TO 600 FEET. THESE NUMBERS REPRESENT THE DEPTH OF THE WELL MIXED LAYER. THERE IS NOT THE EXTENSIVE THICK FOG WHICH COULD BE EXPECTED WITH LIGHT WINDS AT THIS TIME OF YEAR. AT POINT LAY AND WAINWRIGHT THE WINDS ARE DEFINITELY OFFSHORE...AND THE SKY IS CLEAR. THE FAA WEB CAMERAS SHOW THIS BEAUTIFULLY. THIS PARAGRAPH CONTAINS A LARGE PART OF WHAT WE HAVE BEEN ABLE TO FIND ABOUT ARCTIC ALASKAN COAST LOW CLOUDS AND FOG OVER THE PAST 38 YEARS. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .FIRE WEATHER... THE FIRE WEATHER WATCH FOR THE YUKON FLATS AND SURROUNDING UPLANDS REMAINS IN EFFECT. AFTERNOON MINIMUM RELATIVE HUMIDITY THERE IS EXPECTED TO BE 20 TO 30 PERCENT...ROUGHLY 5 PERCENT LOWER THAN YESTERDAY. && .HYDROLOGY... NO HEAVY RAINFALL HAS BEEN OBSERVED IN NORTHERN ALASKA FOR THE PAST 2 DAYS. RIVER LEVELS AT MOST LOCATIONS ARE SLOWLY FALLING FROM MODERATE STAGES. IF THERE IS ANY HEAVY RAINFALL DURING THE NEXT TWO DAYS IT WILL BE LOCALIZED TO SMALL AREAS. && .AFG WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FOR AKZ220. BRISK WIND ADVISORY FOR PKZ240-PKZ245. && $$ TF JUN 12 ______________________________________________________________________ PAFG - Reference: ['this mornings polar orbiting satellite imagery shows mostly'] 619 FXAK69 PAFG 281313 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 513 AM AKDT THU JUN 28 2012 .DISCUSSION... CIRCULATION OVER NORTHERN ALASKA CONTINUES TO BE VERY WEAK...AND THE WEATHER HAS BEEN UNEVENTFUL...UNUSUALLY SO. HIGH PRESSURE ALOFT OVER THE BEAUFORT SEA AND LOW PRESSURE IN THE GULF OF ALASKA HAVE RESULTED IN EASTERLY FLOW OVER THE CENTRAL AND SOUTHERN INTERIOR. A SERIES OF WEAK TROUGHS OF LOW PRESSURE ALOFT IS EXPECTED TO CONTINUE TO MOVE WESTWARD OVER THE INTERIOR OF NORTHERN ALASKA. THESE TROUGHS ARE EXPECTED TO BRING PERIODS OF RAIN TO THE SOUTHERN INTERIOR FOR THE REST OF THIS WEEK. IN THIS PATTERN...THE NORTHERN INTERIOR...THE BROOKS RANGE AND THE INLAND PLAIN OF THE ARCTIC ARE EXPECTED TO CONTINUE TO HAVE RELATIVELY MILD TEMPERATURES AND LITTLE IF ANY PRECIPITATION. THE SOUTHERN INTERIOR IS CONTINUING TO HAVE SHOWERY AND COOL WEATHER. IN THE WESTERN INTERIOR...TEMPERATURES ARE NEAR SEASONAL NORMALS AND LITTLE OF THE RAIN IN THE EASTERN INTERIOR IS REACHING THE AREA. OVER THE WEEKEND...THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS FORECAST THE BEAUFORT SEA HIGH ALOFT TO BUILD DOWN OVER THE EASTERN MAINLAND. THIS SHOULD BRING DRIER AND WARMER WEATHER TO THE EASTERN INTERIOR. AT THE SAME TIME...LOW PRESSURE OVER THE WESTERN CHUKCHI SEA IS FORECAST TO BRING INCREASING SOUTHERLY FLOW OVER THE NORTHWEST COAST. THIS WILL PROBABLY BE ACCOMPANIED BY SOME RAIN. ON MONDAY...LOW PRESSURE ALOFT WILL HAVE MOVED FROM THE NORTHEAST GULF OF ALASKA TO THE SOUTHERN YUKON TERRITORY. SOME TROUGHS ALOFT MAY MOVE FROM THIS SYSTEM TO THE EASTERN INTERIOR. IF SO...THUNDERSTORMS CAN BE EXPECTED NEAR THE YUKON BORDER. AS IS USUAL FOR MEDIUM RANGE FORECASTS...THE OUTLOOK FOR THE SECOND HALF OF NEXT WEEK IS A LITTLE UNCERTAIN. THE GFS MODEL RUN WEDNESDAY AFTERNOON FORECASTS HIGH PRESSURE ALOFT TO PREVAIL OVER THE NORTH HALF OF THE REALM FOR THE SECOND HALF OF NEXT WEEK. IF SO...WARMER AND DRIER WEATHER WILL DEVELOP OVER ALL OF NORTHERN ALASKA EXCEPT THE ALASKA RANGE. AS IS TYPICALLY THE CASE WITH FORECAST MODELS HAVING A SMALLER SCALE FORECAST SYSTEM...THE NAM FORECASTS MORE PRECIPITATION THAN THE GFS. AND AS IS NORMALLY THE CASE...THE NAM FORECASTS MORE PRECIPITATION THAT THE GFS. THE GFS USUALLY IS CLOSER TO THE MARK ON PRECIPITATION FORECASTS...AND IT ISL THE FAVORED MODEL TODAY. IN THE MEDIUM RANGE...THE GFS MODEL FORECAST FOR NEXT WEEK LOOKS MORE REASONABLE THE THE EUROPEAN MODEL FORECAST. THE EUROPEAN MODEL PREDICTS A LARGE LOW ALOFT TO MOVE SOUTHWARD OVER THE BERING SEA COAST OF NORTHERN ALASKA DURING MOST OF NEXT WEEK. THEN...AS SEEMS ODDLY COMMON...THE TWO MODEL FORECASTS PULL CLOSER TOGETHER. BOTH PREDICT A LARGE LOW ALOFT OVER THE GULF OF ALASKA AND HIGH PRESSURE OVER THE YUKON. THIS MORNINGS POLAR ORBITING SATELLITE IMAGERY SHOWS MOSTLY OVERCAST CLOUDS OVER THE SOUTHERN AND CENTRAL INTERIOR...AND A FEW LINGERING CONVECTIVE CLOUDS OVER THE NORTH. THE WESTERN MAINLAND IS ALSO MOSTLY OVERCAST. SKIES ARE PARTLY CLOUDY OVER THE WESTERN SEWARD PENINSULA. THE SUNNY DAY OVER WALES ON WEDNESDAY MAY PROVE TO BE THE MOST BEAUTIFUL WEATHER OUT THERE FOR THE SEASON. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .FIRE WEATHER... THE MOST UNSTABLE AIR MASS WILL REMAIN OVER THE NORTHEASTERN INTERIOR. THUNDERSTORMS IN THE EASTERN INTERIOR WILL BE WET. AFTERNOON MINIMUM RELATIVE HUMIDITY WILL BE ABOVE 50 PERCENT NEARLY EVERYWHERE IN THE REALM. THE LAST LIGHTNING STRIKES RECORDED BY THE ALASKA LIGHTNING DETECTION SYSTEM WERE AROUND 11 PM AKDT EAST OF ARCTIC VILLAGE. YESTERDAY...115 LIGHTNING STRIKES WERE RECORDED...ALL OF THEM IN THE EASTERN BROOKS RANGE AND A FEW OVER THE EASTERN BEAUFORT SEA COAST. && .HYDROLOGY... STREAMS AND RIVERS IN THE ARCTIC CONTINUE TO SLOWLY FALL AS A RESULT OF CONTINUING DRY WEATHER. IN THE INTERIOR...MOST RIVERS ARE AT FAIRLY STEADY LEVELS THAT ARE BELOW BANKFULL. SOME RISES ARE EXPECTED FROM THE RECENT PERIODS RAINFALL IN THE EASTERN AND CENTRAL INTERIOR...ESPECIALLY IN THE TANANA BASIN...WHERE BOTH RAINFALL AND HIGH ELEVATION SNOW AND ICE MELT ARE BRINGING RIVER LEVELS UP. IN THE WEST...RIVER STAGES ARE STEADY OR SLOWLY FALLING. && .AFG WATCHES/WARNINGS/ADVISORIES... NONE. && $$ TF JUN 12 ______________________________________________________________________ PAFG - Reference: ['on this mornings polar orbiting satellite imagery there is a mass'] 231 FXAK69 PAFG 291318 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 518 AM AKDT FRI JUN 29 2012 .DISCUSSION... A PATTERN OF UNUSUALLY WEAK CIRCULATION IS CONTINUING OVER NORTHERN ALASKA. A PORTION OF THE HIGH PRESSURE ALOFT OVER THE BEAUFORT SEA WILL BUILD SOUTHWARD OVER THE CENTRAL ARCTIC AND THE CENTRAL INTERIOR STARTING TONIGHT...AND WILL REMAIN OVER THOSE AREAS THROUGH THE WEEKEND. AN INFLUX OF SOMEWHAT DRIER AIR WILL ACCOMPANY THE HIGH PRESSURE. THE ALASKA LIGHTNING DETECTION SYSTEM RECORDED 1028 STRIKES ON TUESDAY...IN THE NORTHEAST INTERIOR. FOR COMPARISON...ON WEDNESDAY...115 STRIKES...IN THE EASTERN BROOKS RANGE AND EASTERN ARCTIC. ON THURSDAY...52 STRIKES...NEARLY ALL IN THE FAR NORTHEASTERN INTERIOR. THE LARGEST 24-HOUR TOTAL THIS SEASON SO FAR IS 2711 STRIKES ON JUNE 6...MOST IN THE WESTERN INTERIOR. FOR THE PAST SEVERAL DAYS...THE MOST PROMISING SOURCE OF ENERGY AND CHANGE IN CIRCULATION REMAINS THE RUSSIAN FAR EAST...INCLUDING SIBERIA AND CHUKOTKA. SATELLITE IMAGERY OVER THE PAST 12 HOURS HAS SHOWN AN INFLUX OF CLOUDS OVER SIBERIA AND CHUKOTKA HEADED TOWARD NORTHWEST ALASKA. ALTHOUGH MOST OF THE ENERGY WITH THIS INFLUX WILL HEAD NORTH...AND NOT REACH ALASKA...IT IS AN INDICATION OF THINGS TO COME. A SERIES OF SURFACE LOW PRESSURE SYSTEMS ARE MOVING EAST AND NORTHEASTWARD OVER CHUKOTKA. THE FIRST IS FORECAST TO TURN NORTHWARD TONIGHT AND TO WEAKEN OVER THE CENTRAL CHUKCHI SEA SHORTLY AFTERWARD. THE SECOND IS EXPECTED OVER CHUKOTKA ON SUNDAY. INCREASING SOUTHERLY WINDS AT THE SURFACE AND ALOFT WILL DEVELOP OVER THE EASTERN BERING SEA SUNDAY NIGHT. THIS...ACCOMPANIED BY A MODERATELY STRONG TROUGH OF LOW PRESSURE ALOFT...WILL BRING THE FIRST WIDESPREAD RAINFALL TO THE WEST THIS MONTH. THE INCREASED SOUTHERLY WINDS WILL BE CAUSE FOR ISSUANCE FOR THE FIRST MARINE ADVISORIES SINCE EARLY THIS WEEK. RETURNING TO THE MAINLAND...ANOTHER LARGE AREA OF CLOUDS NOW INBOUND OVER THE SOUTHERN YUKON TERRITORY IS EXPECTED TO BRING ANOTHER BOUT OF RAIN AND ISOLATED THUNDERSHOWERS TO THE EASTERN AND CENTRAL INTERIOR TODAY AND TONIGHT. SATELLITE IMAGERY SHOWS THIS SYSTEM TO BE LARGER AND BETTER ORGANIZED THAN ITS TWO PREDECESSORS OVER THE PAST 3 DAYS...SO THE RAINFALL IT BRINGS MAY BE MORE WIDESPREAD THAN THE PRECIPITATION EARLIER THIS WEEK. THE GSM / GLOBAL SPECTRAL MODEL / RUN FROM YESTERDAY FORECASTS A SERIES OF SUCH WEATHER SYSTEMS TO ORIGINATE OVER THE NORTHEASTERN GULF OF ALASKA AND MOVING NORTHWARD...TO BRING MORE SHOWERS TO THE EASTERN INTERIOR. THIS PROCESS IS EXPECTED TO CONTINUE THROUGH THE END OF NEXT WEEK. WESTERN AND ARCTIC ALASKA HAVE HAD LESS THAN NORMAL PRECIPITATION...QUITE A BIT BELOW NORMAL IN THE ARCTIC. / SO FAR THIS MONTH...BARROW HAS HAD 0.09 INCH OF PRECIPITATION AND KOTZEBUE 0.20 INCH. / IT LOOKS LIKE THIS WILL CONTINUE IN THE ARCTIC...WHILE THERE WILL BE RESUMPTION OF MORE NORMAL PRECIPITATION IN THE WEST STARTING NEXT WEEK. A SMALL SURFACE LOW PRESSURE SYSTEM HAS HELD PLACE OVER MACKENZIE BAY FOR THE PAST SEVERAL DAYS. BARTER ISLAND CONTINUES TO HAVE WINDS FROM THE WEST...WHILST THE REST OF THE ALASKAN ARCTIC COAST HAS HAD GENERALLY NORTHEAST WINDS. THE LOW CLOUDS AND FOG WHICH HELD OVER MOST OF THE ARCTIC COAST FOR SEVERAL DAYS UNEXPECTEDLY LIFTED YESTERDAY. BARTER ISLAND HAS REMAINED SOCKED IN. ITS WEST WINDS ALONE DO NOT EXPLAIN THIS. FARTHER WEST...THE WEB CAMERAS SHOW ANOTHER BEAUTIFUL DAY BEGINNING IN WALES. THE MEDIUM RANGE FORECASTS DIVERGE STARTING TUESDAY NIGHT. THE EUROPEAN MODEL FORECASTS THE INCOMING LOW PRESSURE FROM CHUKOTKA TO REACH THE WESTERN GULF OF ALASKA TUESDAY NIGHT...WHILE THE GSM RUN FROM YESTERDAY EVENING FORECASTS IT TO HAVE MORE ENERGY AND TO HOLD OVER THE EASTERN BERING SEA UNTIL LATE NEXT WEEK. FOLLOWING THAT...THE GSM MODEL FORECASTS THIS LOW TO MOVE INTO THE WESTERN GULF OF ALASKA. IN A MANNER OF SPEAKING...THE GSM MODEL FORECASTS THIS IMPORTANT WEATHER SYSTEM TO CATCH UP WITH THE EUROPEAN MODEL. THIS PROCESS OF RECONVERGENCE OF MODEL FORECASTS IS OFTEN SEEN...FOR REASONS NOT YET WELL KNOWN. ON THIS MORNINGS POLAR ORBITING SATELLITE IMAGERY THERE IS A MASS OF CONVECTIVE CLOUDS OVER THE KOYUKUK AND CENTRAL YUKON VALLEYS. THIS CLOUD AREA ORIGINATED OVER THE NORTHEASTERN INTERIOR YESTERDAY...AND IT IS LESSENING IN EXTENT AND APPARENT STRENGTH. IT HAS BROUGHT VERY LITTLE RAINFALL INTO NORTHWEST ALASKA AND LITTLE MORE IS EXPECTED. THIS MORNING...THE BARROW SEA ICE WEB CAM SHOWS OPEN TO CLOSE PACK OF ROTTING ICE. THERE HAS NOT BEEN MUCH CHANGE THERE THIS WEEK. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .FIRE WEATHER... THE AIRMASS OVER THE INTERIOR REMAINS MOIST AND UNSTABLE...ESPECIALLY OVER THE NORTHEASTERN INTERIOR. ALONG WITH A SLIGHTLY DRIER AIRMASS ON SATURDAY AND SUNDAY...THE AIRMASS OVER THE EASTERN INTERIOR WILL BE MORE UNSTABLE THAN TODAY. MINIMUM RELATIVE HUMIDITY THIS AFTERNOON WILL BE NO LOWER THAN 45 PERCENT...AND IN MOST PARTS OF NORTHERN ALASKA...ABOVE 60 PERCENT. ASIDE FROM GUSTY WINDS NEAR THUNDERSTORMS...WIND FLOW OVER NORTHERN ALASKA CONTINUES TO BE VERY LIGHT. && .HYDROLOGY... MOST RIVERS IN NORTHERN ALASKA ARE AT MODERATE LEVELS AND SLOWLY FALLING. IN THE EASTERN BROOKS RANGE...WARMER TEMPERATURES AND SOME ISOLATED THUNDERSHOWERS HAVE BROUGHT SMALL RISES TO SOME RIVERS THERE. IN THE SOUTHEASTERN INTERIOR...RAIN SHOWERS AND MILD TEMPERATURES ALOFT HAVE BROUGHT RIVERS UP SOME IN THE TANANA RIVER BASIN AND PARTICULARLY ON THE GOODPASTER RIVER. && .AFG WATCHES/WARNINGS/ADVISORIES... NONE. && $$ TF JUN 12 ______________________________________________________________________ PAFG - Reference: ['this mornings polar orbiting satellite imagery shows a shrinking'] 740 FXAK69 PAFG 301339 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 539 AM AKDT SAT JUN 30 2012 .DISCUSSION... THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS FORECAST THE LONG LIVED EASTERLY FLOW ALOFT TO CHANGE TODAY. HIGH PRESSURE ALOFT OVER THE BEAUFORT SEA IS EXTENDING SOUTHWARD...OVER THE EASTERN INTERIOR. WINDS ALOFT WILL BECOME NORTHERLY NEAR THE YUKON BORDER. A TROUGH ALOFT EXTENDS NORTHWARD OVER THE YUKON TERRITORY. SATELLITE IMAGERY SHOWS AN AREA OF CLOUDS OVER THE SOUTHEASTERN INTERIOR AHEAD OF THE TROUGH. THIS FEATURE HAS BROUGHT WIDESPREAD RAIN OVER THE AREA. A SECOND BAND OF CLOUDS IS EXPECTED TO MOVE IN A SIMILAR MANNER ACROSS THE YUKON OVER THE ALASKA BORDER LATER TODAY. THIS IS EXPECTED TO BRING MORE SHOWERS...AND SOME THUNDERSTORMS...TO THE EASTERN INTERIOR THIS AFTERNOON AND EVENING. INDEED...THIS TROUGH ALOFT IS FORECAST TO HOLD OVER THE YUKON TERRITORY THROUGH TUESDAY...AND THEN TO SHRINK INTO A SMALL LOW ALOFT TO MOVE WESTWARD OVER THE BROOKS RANGE TUESDAY NIGHT AND WEDNESDAY. THIS IS THE BASIS OF THE NUMEROUS SHOWERS IN THIS MORNINGS FORECAST FOR THE SOUTHEASTERN INTERIOR...ESPECIALLY THE FORTYMILE COUNTRY. A LARGE LOW PRESSURE ALOFT NOW OVER THE SOUTHERN CHUKCHI SEA IS STRENGTHENING AND ADVANCING TOWARD ALASKA. THIS WILL BRING SOUTHERLY FLOW OVER THE WESTERN HALF OF THE REALM THIS WEEKEND...AND THEN STRENGTHEN MONDAY AND TUESDAY. THE RESULT OF THESE CHANGES IN CIRCULATION WILL BE CLOUDIER AND WINDIER WEATHER...AND THE ONSET OF SOME RAIN ON THE WEST COAST ON SUNDAY THROUGH TUESDAY. THE GFS MODEL FORECASTS THE LARGE LOW ALOFT TO REACH THE CENTRAL BERING SEA EARLY TUESDAY...AND TO MOVE INTO THE WESTERN GULF OF ALASKA THURSDAY NIGHT. BY FRIDAY NIGHT...THE EASTERLY FLOW OVER THE REALM WILL RETURN...BETWEEN A HIGH ALOFT IN THE BEAUFORT SEA AND A LARGE LOW IN THE GULF OF ALASKA. SOMEWHAT WARMER...DRIER AND MOSTLY SUNNY WEATHER IS EXPECTED OVER MOST OF NORTHERN ALASKA NEXT WEEKEND. ISOLATED LATE AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED OVER MUCH OF NORTHERN ALASKA...INCLUDING SOME OF THE COASTAL REGIONS...NEXT WEEKEND. THESE THUNDERSHOWERS WILL GENERALLY NOT BRING AS MUCH RAIN AS THE ONES THIS WEEK DID. THIS MORNINGS POLAR ORBITING SATELLITE IMAGERY SHOWS A SHRINKING AREA OF CONVECTIVE CLOUDS OVER THE WESTERN BROOKS RANGE. THESE ARE LEFT OVER FROM THUNDERSTORMS WHICH WERE OVER THE CENTRAL BROOKS RANGE FRIDAY EVENING. THE ALASKA LIGHTNING DETECTION SYSTEM RECORDED 188 LIGHTNING STRIKES IN ALASKA FRIDAY AND FRIDAY EVENING. MOST WERE IN THE EASTERN BROOKS RANGE. A SMALLER CLUSTER WAS OVER THE FORTYMILE COUNTRY. NEARLY ALL OF THE INLAND AREAS OF NORTHERN ALASKA ARE PARTLY CLOUDY THIS MORNING...BUT CLOUD COVER IS EXPECTED TO INCREASE THIS AFTERNOON. HIGHLIGHTS OF THIS MORNINGS WEB CAMERA IMAGERY INCLUDE PERFECT CLEAR SKIES OVER MT. MCKINLEY AND HEAVY FOG AT DEADHORSE AND CHANDALAR SHELF. THESE ARE AT... HTTP://AKWEATHERCAMS.FAA.GOV COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .FIRE WEATHER... THE AIRMASS OVER THE EASTERN AND CENTRAL INTERIOR IS EXPECTED TO BE UNSTABLE THROUGH MONDAY...ESPECIALLY THE EASTERN INTERIOR. ISOLATED LATE AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED IN THE EASTERN AND CENTRAL INTERIOR. THERE WILL BE LESS RAINFALL WITH THESE THAN THERE WAS IN THE FIRST 6 DAYS OF THIS WEEK. MINIMUM HUMIDITY WILL BE ABOVE 50 PERCENT NEARLY EVERYWHERE...ALTHOUGH SOME INTERIOR SITES WILL HAVE HUMIDITY AS LOW AS 40 PERCENT. && .HYDROLOGY... MOST NORTHERN ALASKA RIVERS ARE AT LEVEL OR SLOWLY FALLING STAGES. THE KNOWN EXCEPTIONS ARE... THE SALCHA...FORTYMILE...TANANA RIVER NEAR FAIRBANKS AND THE KOYUKUK RIVERS ARE HAVING SMALL RISES... THE GOODPASTER RIVER / NEAR BIG DELTA / CRESTED AT ABOUT 4 AM FRIDAY... THE SAGAVANIRKTOK RIVER ROSE SOME ON THURSDAY AND IS REMAINING AT NEARLY STEADY STAGES NOW. NO RIVERS IN NORTHERN ALASKA ARE CLOSE TO BANKFUL. A STEADY RATE OF SNOW AND ICE MELT IN THE ALASKA RANGE IS HOLDING STREAMS AND RIVERS IN THE SOUTHERN TANANA VALLEY AT LEVEL STAGES. IN THE WESTERN INTERIOR...LITTLE IF ANY RAIN IS EXPECTED...SO RIVER STAGES ARE CONTINUING TO RECEDE VERY SLOWLY. THE WESTERN COASTAL ZONES WILL HAVE SOME RAIN OVER THE NEXT THREE DAYS. THE RIVERS THERE ARE NOT EXPECTED TO HAVE SIGNIFICANT RISES IN THE NEXT THREE DAYS. IN THE ARCTIC...STREAMS AND RIVERS ARE AT LEVEL OR VERY SLOWLY DECLINING LEVELS WITH THE EXCEPTION OF THOSE FED BY HIGHLAND SNOW MELT IN THE BROOKS RANGE. && .AFG WATCHES/WARNINGS/ADVISORIES... NONE. && $$ TF JUN 12 ______________________________________________________________________ PAFG - Reference: ['todays polar orbiting satellite imagery shows a large cluster of'] 953 FXAK69 PAFG 032307 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 307 PM AKDT TUE JUL 3 2012 .DISCUSSION... THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS BOTH FORECAST THE LOW ALOFT NOW ABOUT 200 MILES WEST OF NUNIVAK ISLAND TO CONTINUE ITS SOUTHEASTWARD COURSE TO ARRIVE OVER BRISTOL BAY WEDNESDAY AFTERNOON BY THURSDAY EVENING...THE GFS MODEL FORECASTS THIS LOW TO BE OVER THE WESTERN GULF OF ALASKA...AND THE NAM MODEL FORECASTS IT TO BE JUST SOUTH OF THE ALASKA PENINSULA. TO DAYS GFS MODEL FORECAST IS CONSISTENT WITH MODEL RUNS BACK TO LAST FRIDAY AND IT IS TO DAYS PREFERRED MODEL. THE GFS MODEL FORECASTS THE LOW ALOFT TO REMAIN OVER THE GULF OF ALASKA UNTIL MID WEEK NEXT WEEK...WHEN IT IS EXPECTED TO MOVE NORTHEASTWARD INTO THE YUKON TERRITORY. THERE IS A SMALL LOW ALOFT OVER THE YUKON TERRITORY FOR MORE THAN A DAY NOW. THE GFS MODEL FORECASTS THIS LOW PRESSURE TO WEAKEN AND TO BE ABSORBED IN THE CIRCULATION AROUND THE GULF OF ALASKA LOW LATE TOMORROW. THIS AGREES WITH THE NAM MODEL FORECAST. CIRCULATION AROUND THIS LOW ALOFT HAS BROUGHT A SERIES OF BANDS OF CLOUDS FROM THE YUKON TERRITORY TO THE EASTERN AND CENTRAL INTERIOR. THESE HAVE BEEN ACCOMPANIED BY PERIODS OF LIGHT RAIN. AS IT TYPICALLY THE CASE...THE NAM MODEL IS FORECASTING TOO MUCH PRECIPITATION IN NEARLY ALL OF NORTHERN ALASKA. FURTHERMORE...THE SUCCESSIVE 6 HOUR PRECIPITATION FORECASTS APPEAR TO SHIFT BACK AND FORTH IN AN UNNATURAL MANNER. THE GFS PRECIPITATION FORECAST LOOKS REASONABLE. AS IT HAS FOR SEVERAL DAYS NOW...THE GFS FORECASTS HIGH PRESSURE ALOFT TO REMAIN OVER THE ARCTIC SECTION THIS WEEK. NEXT WEEK...THE GFS MODEL FORECASTS THE HIGH PRESSURE TO MOVE FURTHER WEST...TO BE OVER THE RUSSIAN FAR EAST BY THE MIDDLE OF NEXT WEEK. OVERALL...THIS PATTERN OF CIRCULATION ALOFT CAN BE EXPECTED TO BE ASSOCIATED WITH FAIRLY UNEVENTFUL WEATHER THROUGHOUT THE REALM. TODAYS POLAR ORBITING SATELLITE IMAGERY SHOWS A LARGE CLUSTER OF CONVECTIVE CLOUDS OVER THE CENTRAL BROOKS RANGE ...THE KOYUKUK VALLEY ...AND THE CENTRAL INTERIOR. THESE CLOUDS PRODUCED LIGHTNING STRIKES UNTIL 8.15 AM AKDT THIS MORNING. THIS IS A REAL UNUSUAL EVENT IN NORTHERN ALASKA. IN LATE SPRING AND SUMMER...LIGHTNING STRIKES NORMALLY START IN THE EARLY AFTERNOON AND RUN AS LATE AS MIDNIGHT OR INTO THE VERY EARLY MORNING HOURS. THE NAM20 COMPUTER WEATHER FORECAST MODEL FORECASTS THE AIR MASS OVER THE NORTHERN INTERIOR AND THE BROOKS RANGE TO BE QUITE UNSTABLE THIS AFTERNOON AND EVENING...AND PRETTY MUCH THE SAME WEDNESDAY AND THURSDAY. THE AIR MASS OVER THE EASTERN INTERIOR IS FORECAST TO BE MILDLY UNSTABLE. THE STABILITY FORECAST FOR THE EASTERN INTERIOR IS UNDER DONE. THE MORNING WEATHER BALLOON SOUNDING FOR FAIRBANKS SHOWED POSITIVE ENERGY OF 920 JOULES PER KILOGRAM. THIS IS A LOT OF ENERGY...NOT OFTEN SEEN IN NORTHERN ALASKA. FURTHERMORE...THE SOUNDING SHOWED THAT AIR RISING FROM THE BOUNDARY LAYER WILL EASILY REACH THE TROPOPAUSE...WHICH IS AT AN ALTITUDE NEAR 34000 FEET TODAY. THIS WILL...HOWEVER REQUIRE A SURFACE TEMPERATURE AROUND 71 DEGREES. CONSIDERING THE EXTENSIVE CLOUD COVER...RAINFALL AND AREAS OF FOG OVER THE AREA...THIS MAY NOT HAPPEN. IF IT DOES...THE RESULT WILL BE EVENING THUNDERSTORMS. THE VISIBLE SATELLITE IMAGERY SHOWED EXTENSIVE CONVECTIVE CLOUDS AND THUNDERSTORMS OVER THE EASTERN INTERIOR ...AND OVER THE NORTH SLOPES OF THE BROOKS RANGE YESTERDAY EVENING. ONE INTERESTING FEATURE WAS AN AREA OF FOG WHICH APPEARED BETWEEN CAPE HALKETT AND PRUDHOE BAY SHORTLY AFTER MIDNIGHT. THIS AREA OF FOG EXPANDED AND DRIFTED WESTWARD AND SOUTHWARD THROUGH 7 AM AKDT THIS MORNING. AFTER THAT...IT CONTINUED MOVING TOWARD THE SOUTHWEST. THE INLAND PORTION OF THE FOG CLEARED FROM THE EAST BY 11 AM AKDT THIS MORNING. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .FIRE WEATHER... THE UNSTABLE AIR MASS WHICH PREVAILS OVER MOST OF THE INTERIOR HAS PRODUCED THUNDERSTORMS OVER THE EASTERN INTERIOR AND PARTS OF THE BROOKS RANGE AND THE UPPER COLVILLE BASIN IN THE WESTERN ARCTIC. THE ALASKA LIGHTNING DETECTION SYSTEM RECORDED 1171 STRIKES ON SUNDAY AND 1884 STRIKES YESTERDAY /MONDAY /. THE THUNDERSTORMS HAVE BEEN WET. MINIMUM RELATIVE HUMIDITY HAS BEEN ABOVE 40 PERCENT NEARLY EVERYWHERE. PARTS OF THE NORTHERN INTERIOR HAVE HAD MINIMUM RELATIVE HUMIDITY ALMOST AS LOW AS 30 PERCENT. && .HYDROLOGY... RAINFALL IN THE PAST 24 HOURS IS FROM 1/4 TO 1/2 INCH IN MOST OF THE EASTERN INTERIOR. A FEW LOCATIONS IN THE SOUTHEASTERN INTERIOR HAVE HAD 0.70 INCH IN THE PAST 24 HOURS AND OVER 2 INCHES IN THE PAST 2 DAYS. RIVERS IN THE EASTERN INTERIOR...THE PORCUPINE ...FORTYMILE ... UPPER YUKON AND TANANA ARE RISING AND ARE DUE TO CREST WEDNESDAY AND THURSDAY. STAGES ARE OR SOON WILL BE WITHIN A FOOT OR TWO BELOW MINOR FLOOD STAGE ON THE SALCHA ...TANANA AT BIG DELTA ...NABESNA ...GOODPASTER AND CHISANA RIVERS. && .AFG WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH FOR AKZ224. SMALL CRAFT ADVISORY FOR PKZ220-PKZ225-PKZ230-PKZ245. && $$ TF JUL 12 ______________________________________________________________________ PAFG - Reference: ['todays polar orbiting satellite imagery shows cloudy skies nearly'] 264 FXAK69 PAFG 050013 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 413 PM AKDT WED JUL 4 2012 .DISCUSSION... THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS FORECAST THE LARGE LOW ALOFT NOW OVER BRISTOL BAY TO MOVE INTO THE GULF OF ALASKA...WHERE IT WILL REMAIN THROUGH NEXT TUESDAY. THIS FORECAST IS CONSISTENT WITH PREVIOUS MODEL RUNS OVER THE PAST SEVERAL DAYS. CIRCULATION AROUND THE LOW WILL INCLUDE SOME INVERTED TROUGHS OF LOW PRESSURE ALOFT...WHICH ARE EXPECTED MOVE WESTWARD OVER THE INTERIOR AND BERING SEA COASTAL ZONES. THESE DISTURBANCES WILL BRING RAIN SHOWERS TO THOSE AREAS. ON THURSDAY...THE LOW ALOFT IS FORECAST TO MOVE NORTHWARD OVER THE ALASKA MAINLAND. GRADUALLY WEAKENING CIRCULATION AROUND THE LOW WILL COVER ALL OF THE MAINLAND. THROUGH THE REST OF THE WEEK. THESE PATTERNS CAN BE EXPECTED TO BRING SHOWERS TO THE INTERIOR DAY AFTER DAY...AND SOMETIMES TO THE BERING SEA COASTAL ZONES. THE AIR MASS OVER NORTHERN ALASKA IS PRESENTLY MOST UNSTABLE OVER THE BROOKS RANGE ZONES. THE NAM20 COMPUTER WEATHER FORECAST MODEL PROJECTS THE AREA OF UNSTABLE AIR TO EXPAND SOUTHWARD OVER THE INTERIOR WITH THE EXCEPTIONS OF THE SOUTHWEST INTERIOR AND ALASKA RANGE ZONES BY FRIDAY. TODAYS POLAR ORBITING SATELLITE IMAGERY SHOWS CLOUDY SKIES NEARLY EVERYWHERE IN THE REALM...WITH THE EXCEPTIONS OF SOME OF THE NORTHWEST INTERIOR AND ABOUT HALF OF THE NORTH SLOPES OF THE BROOKS RANGE. INCREASED NORTHEAST WINDS OVER THE ARCTIC COASTAL ZONES CLEARED MOST OF THE AREA TODAY...BUT LOW CLOUDS AND PATCHY FOG ARE EXPECTED TO RETURN TONIGHT AS THE WIND GRADUALLY DIMINISHES. AS WAS THE CASE YESTERDAY...A LARGE AREA OF LOW CLOUDS FORMED OVERNIGHT ON THE WEST HALF OF THE ARCTIC INLAND COASTAL PLAIN. THE AREA COVERED BY THESE LOW CLOUDS DECREASED STEADILY THROUGH THE DAY TODAY...BUT PRUDHOE BAY AND IVOTUK CLEARED ONLY BRIEFLY. HIGHLIGHTS OF TODAYS WEB CAMERA IMAGERY INCLUDE MANY VIEWS OF GLORIOUS SUNNY BLUE SKY OVER THE ARCTIC ZONES...INCLUDING CHANDALAR SHELF...BARROW...AND A DRAMATIC CLEARING AT MID AFTERNOON AT WALES ON THE BERING STRAIT COAST. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .FIRE WEATHER... ISOLATED THUNDERSTORMS ARE FORECAST FOR THE BROOKS RANGE AND FOR THE INTERIOR ZONES EXCLUDING THE ALASKA RANGE ZONES AND THE SOUTHWEST INTERIOR. THE THUNDERSTORMS WILL BE WET. MINIMUM RELATIVE HUMIDITY WILL BE ABOVE 40 PERCENT JUST ABOUT EVERYWHERE...AND IN MUCH OF THE REALM IT WILL BE ABOVE 50 PERCENT. AS OF 3.15 PM AKDT THIS AFTERNOON THE ALASKA LIGHTNING DETECTION SYSTEM HAS RECORDED 62 STRIKES...ALL IN THE EASTERN BROOKS RANGE. ON THE OTHER SIDE OF THE BORDER IN CANADA...A COUPLE DOZEN STRIKES HAVE BEEN RECORDED ON THE MACKENZIE RIVER DELTA. FOR COMPARISON...THERE WERE 843 LIGHTNING STRIKES IN ALASKA ON TUESDAY. && .HYDROLOGY... EXTENSIVE RAINFALL IN THE EASTERN INTERIOR BROUGHT RIVER STAGES ON A NUMBER OF RIVERS CLOSE TO BANKFUL OR A LITTLE ABOVE THAT DURING THE PAST SEVERAL DAYS. THE TANANA RIVER AT FAIRBANKS IS EXPECTED TO CREST THIS EVENING AND THEN TO REMAIN NEAR BANK FULL THROUGH FRIDAY BEFORE BEGINNING TO SLOWLY RECEDE OVER THE WEEKEND. THE TANANA RIVER IS EXPECTED TO CREST AT NENANA THURSDAY. THE SALCHA RIVER CRESTED YESTERDAY. THE PORCUPINE RIVER NEAR THE YUKON BORDER IS PRESENTLY CRESTING. WATER LEVELS ON THE NABESNA AND CHISANA RIVERS WILL REMAIN ELEVATED THROUGH FRIDAY. THE GOODPASTER RIVER NEAR BIG DELTA CRESTED AT THE LEVEL OF MINOR FLOODING ON MONDAY AFTERNOON...AND HAS GENERALLY HAD FALLING...BUT FLUCTUATING LEVELS SINCE THEN. IT IS EXPECTED TO SLOWLY RECEDE OVER THE NEXT SEVERAL DAYS. ELSEWHERE IN NORTHERN ALASKA...RIVERS ARE AT STEADY OR SLOWLY FALLING LEVELS WELL BELOW BANK FULL. && .AFG WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY FOR PKZ235-PKZ240. && $$ TF JUL 12 ______________________________________________________________________ PAFG - Reference: ['polar orbiting satellite imagery over the past three days has'] 466 FXAK69 PAFG 201358 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 558 AM AKDT FRI JUL 20 2012 .DISCUSSION... THE HIGH ENERGY WESTERLY FLOW ALOFT OVER NORTHERN ALASKA LOOKS LIKE IT WILL DIMINISH...AT LEAST FOR A DAY OR SO...STARTING SATURDAY NIGHT. THE GFS AND NAM COMPUTER WEATHER FORECAST MODELS ARE IN GOOD AGREEMENT ON THIS. BOTH MODELS FORECAST WEAK HIGH PRESSURE ALOFT TO BUILD OVER THE SOUTHEASTERN ALASKA MAINLAND SATURDAY NIGHT. THE GFS AND EUROPEAN COMPUTER WEATHER FORECAST MODELS PROJECT A RESPITE FROM SATURDAY NIGHT THROUGH MONDAY NIGHT...FOLLOWED BY INCREASING WEST AND SOUTHWEST WINDS ALOFT TUESDAY. AS IS USUALLY TRUE FOR HIGH ENERGY CIRCULATION ALOFT...COMPUTER WEATHER FORECAST MODELS DIVERGE SIGNIFICANTLY ABOUT 5 DAYS INTO THE FORECAST. THIS IS TRUE FOR THE THURSDAY EVENING GFS AND EUROPEAN MODEL RUNS. THE MODELS DIFFER SIGNIFICANTLY STARTING WITH THE FORECAST FOR NEXT WEDNESDAY. THE EUROPEAN MODEL FORECASTS HIGH PRESSURE ALOFT TO BUILD DECISIVELY NORTHWARD OVER THE ALASKA MAINLAND STARTING NEXT WEDNESDAY...WITH WEAKER CIRCULATION THROUGH THE END OF THIS MONTH. THE GFS MODEL PREDICTS VIGOROUS WESTERLIES FROM NEXT TUESDAY THROUGH THE END OF JULY. SINCE A CONTINUATION OF HIGH ENERGY WEATHER OF A DURATION CLOSE TO TEN DAYS IS VERY UNLIKELY IN NORTHERN ALASKA IN SUMMER...THE EUROPEAN MODEL PROJECTION LOOKS MUCH MORE REASONABLE THAN THAT OF THE GFS. SATELLITE IMAGERY THIS MORNING SHOWS AN INBOUND OCCLUDED FRONT APPROACHING FROM BRISTOL BAY. THIS WEATHER SYSTEM IS EXPECTED TO BRING RAIN TO THE SOUTHWESTERN INTERIOR LATER TODAY AND TONIGHT. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .FIRE WEATHER... THE STRONG SHORT WAVE ALOFT THAT CROSSED THE INTERIOR FROM THE WEST ON THURSDAY AFTERNOON TO ITS CURRENT LOCATION NEAR THE YUKON BORDER WAS A KEY FACTOR IN A MAJOR LIGHTNING DAY FOR INTERIOR ALASKA. NONE OF THE WEATHER BALLOON SOUNDINGS RECORDED INSTABILITY. THE DYNAMICS OF THE SHORT WAVE WERE THE FACTOR. AS OF 5.50 AM AKDT THIS MORNING...A TOTAL OF 2034 STRIKES WERE RECORDED BY THE ALASKA LIGHTNING DETECTION SYSTEM DURING THE PAST 24 HOURS. THE FIRST AREA WAS A BAND ABOUT 100 MILES WIDE...EXTENDING FROM KALTAG TO THE CENTRAL INTERIOR. LIGHTNING OCCURRED IN THIS AREA FROM MID DAY THURSDAY INTO THE EVENING. THE SECOND AREA INCLUDES THE FORTYMILE COUNTRY...DELTANA AND TANANA FLATS...AND THE EASTERN ALASKA RANGE. LIGHTNING BEGAN IN THIS AREA AS STRIKES IN THE FIRST AREA WERE ENDING. SINCE THE LIGHTNING THERE IS CONTINUING...THE NORTHWAY TERMINAL AVIATION FORECAST WAS UPDATED TO INCLUDE MORNING THUNDERSTORMS -- A WEATHER EVENT JUST ABOUT UNHEARD OF. OVERALL...THIS WAS AN EXTRAORDINARY OUTBREAK OF MID LATITUDE VARIETY WEATHER. THE STRONG WESTERLY FLOW ALOFT HELPED STRENGTHEN IT...AND TO RAPIDLY CARRY IT OVER THE REALM. ONLY A BRIEF PERIOD OF WARMER WEATHER / AFTERNOON HIGHS IN THE 70S / IS EXPECTED IN THE EASTERN INTERIOR ON SUNDAY AND MONDAY. A RESUMPTION OF FAST WEST AND SOUTHWEST FLOW ALOFT ON TUESDAY IS EXPECTED TO BRING A RESUMPTION OF MOSTLY CLOUDY AND RAINY WEATHER TO ALL OF NORTHERN ALASKA ON TUESDAY AND WEDNESDAY NEXT WEEK. OBVIOUSLY...THIS WEATHER PATTERN WILL SERVE TO GREATLY SUPPRESS FIRE BEHAVIOR. && .HYDROLOGY... DURING THE PAST THREE DAYS...MOST OF THE NOATAK...KOBUK...AND KOYUKUK VALLEYS HAVE HAD 1 TO 2 INCHES OF RAIN. THE CENTRAL INTERIOR...THE MIDDLE TANANA VALLEY AND THE UPPER TANANA VALLEY AND FORTYMILE COUNTRY HAVE HAD SIMILAR AMOUNTS OF RAIN IN THE PAST THREE DAYS. POLAR ORBITING SATELLITE IMAGERY OVER THE PAST THREE DAYS HAS SHOWN A REMARKABLE SERIES OF VIGOROUS CLUSTERS OF HEAVY RAINCLOUDS MOVING FROM THE CHUKOTSK PENINSULA AND SEWARD PENINSULA REGIONS ACROSS THE NORTHWEST AND EASTERN INTERIOR. THESE HAVE DISPLAYED THE STRENGTH USUALLY SEEN IN AUTUMN IN THE MID LATITUDES. THE LAST IN THIS SERIES OF SHORT WAVES ALOFT IN STRONG WESTERLY FLOW IS NOW OVER THE FORTYMILE COUNTRY...DELTANA AND TANANA FLATS...AND THE EASTERN ALASKA RANGE. THIS CLUSTER OF HEAVY RAINCLOUDS HAS BEEN PRODUCING LIGHTNING STRIKES ALL NIGHT LONG -- A REMARKABLE OCCURRENCE IN ALASKA. THIS WEEK BEGAN WITH FAIRLY LOW STAGES ON NORTHERN ALASKA RIVERS...AND MOST WATERCOURSES IN NORTHERN ALASKA ARE STILL AT LOW STAGES IN SPITE OF THE RAIN. THE AMOUNT OF RAINFALL THIS WEEK IS SURE TO CHANGE THIS SITUATION. HEADWATER STREAMS IN THE KOBUK AND KOYUKUK VALLEYS...AND IN THE FORTYMILE COUNTRY...ARE SURE TO RISE. AS OF 5 AM AKDT THIS MORNING...ONLY A COUPLE OF REPORTING GAGES HAVE SHOWN SIGNIFICANT RISES. THE LARGEST HAS BEEN ON BIRCH CREEK ABOVE TWELVE MILE CREEK. THIS IS IN YUKON TANANA UPLANDS ABOUT MIDWAY BETWEEN FAIRBANKS AND CIRCLE CITY...AT AN ELEVATION 1981 FEET. THE RIVER HAS COME UP 2 1/2 FEET IN THE PAST 30 HOURS. NONETHELESS...THE DOWNPOURS IN THE SOUTHEASTERN INTERIOR IN THE PAST 24 HOURS ARE SURE TO CAUSE RAPID SURGES IN SOME SMALL BASINS. && .AFG WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY FOR PKZ230-PKZ235. && $$ TF JUL 12 ______________________________________________________________________ PAFG - Reference: ['the early morning polar orbiting satellite imagery shows the cold'] 930 FXAK69 PAFG 211357 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 557 AM AKDT SAT JUL 21 2012 .DISCUSSION... THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS HAVE SIMILAR PROJECTIONS THROUGH SUNDAY NIGHT. A MODERATELY STRONG SHORT WAVE ALOFT NOW EXTENDING FROM BARROW TO NOME IS EXPECTED TO REACH THE EASTERN BEAUFORT SEA LATE THIS EVENING. THE COLD FRONT AHEAD OF THIS SHORT WAVE NOW EXTENDS FROM BARTER ISLAND TO THE YUKON DELTA. THE FRONT IS FORECAST TO MOVE EAST AND TO DISSIPATE OVER MACKENZIE BAY AND THE CENTRAL INTERIOR THIS EVENING. THIS COLD FRONT HAD STRENGTH. SNOW BEGAN IN BARROW LATE FRIDAY MORNING...AND HAS CONTINUED THERE STEADILY SINCE MIDNIGHT. AFTER THE PASSAGE OF THE SHORT WAVE ALOFT INTO THE CANADIAN ARCTIC...WEAK HIGH PRESSURE ALOFT IS FORECAST TO BUILD OVER THE EASTERN INTERIOR ON SUNDAY. THIS PATTERN FAVORS WARMER AND SOMEWHAT DRIER WEATHER IN THE EASTERN INTERIOR ON SUNDAY. STARTING ON SUNDAY...A SLOW MOVING LOW PRESSURE AREA ALOFT NOW MOVING TOWARD SOUTHWEST ALASKA WILL EXPAND OVER THE WESTERN INTERIOR. SCATTERED SHOWERS ARE EXPECTED OVER THE CENTRAL AND WESTERN INTERIOR WITH THIS. ON SUNDAY NIGHT AND MONDAY...ANOTHER STRONG SHORT WAVE ALOFT IS FORECAST TO MOVE FROM THE FAR WESTERN CHUKCHI SEA OVER CHUKOTKA. MODERATELY STRONG SOUTHWEST FLOW ALOFT IS EXPECTED TO DEVELOP OVER ARCTIC AND THE BERING SEA COAST MONDAY AND TUESDAY. THE GFS AND EUROPEAN MODELS ARE IN BASIC AGREEMENT ON THE FORECAST THROUGH TUESDAY. EMBEDDED IN THIS SHORT WAVE ALOFT IS A SURFACE LOW PRESSURE SYSTEM NOW IN THE FAR SOUTHWEST CHUKCHI SEA. THIS SURFACE LOW...AND ITS WEATHER FRONT...ARE EXPECTED TO BE CLOSE TO ALASKAS CHUKCHI SEA COAST ON MONDAY. INCREASING SOUTH WINDS ARE FORECAST FOR THE WESTERN ARCTIC COAST ON SUNDAY...AND ON THE BERING SEA COAST MONDAY AND MONDAY NIGHT. AS WAS THE CASE YESTERDAY...THE EUROPEAN MODEL AND THE GFS MODEL DIVERGE STARTING WITH THE FORECAST FOR NEXT TUESDAY NIGHT. THE GFS HOLDS SOUTHWEST FLOW ALOFT OVER THE REALM FROM TUESDAY NIGHT THROUGH THE REST OF JULY...WHILE THE EUROPEAN MODEL FORECASTS HIGH PRESSURE ALOFT TO DECISIVELY BUILD OVER THE ENTIRE INTERIOR ON WEDNESDAY. GOING FORWARD FROM WEDNESDAY...GFS FORECASTS INCREASING SOUTHWEST FLOW ALOFT TO RESUME OVER NEARLY THE ENTIRE REALM FOR THE REST OF JULY. THE EUROPEAN MODEL PREDICTS HIGH PRESSURE AND WEAK CIRCULATION ALOFT OVER THE INTERIOR. THE EUROPEAN MODEL FORECAST OF HIGH PRESSURE ALOFT REBUILDING OVER THE INTERIOR NEXT WEEK LOOKS BASICALLY CONSISTENT WITH ITS PREVIOUS RUN. IN THIS REGARD IT IS REASONABLE. HOWEVER...THE STRENGTH OF THE HIGH PRESSURE ALOFT WHICH THE EUROPEAN MODEL FORECASTS OVER WESTERN CANADA AND EASTERN ALASKA FOR NEXT WEEKEND LOOKS LIKE IT IS OVERDONE. THEREFORE...IT DOES NOT SEEM REASONABLE TO EXPECT INTERIOR ALASKA TEMPERATURES TO GET MUCH BEYOND 80 DEGREES NEXT WEEKEND. THE GFS AND EUROPEAN MODEL FORECASTS ARE SIMILAR IN ONE IMPORTANT REGARD. THIS IS THE PERSISTENCE OF STRONG LOW PRESSURE ALOFT OVER THE CHUKCHI SEA. THE EARLY MORNING POLAR ORBITING SATELLITE IMAGERY SHOWS THE COLD FRONT FROM BARTER ISLAND TO THE YUKON DELTA GRADUALLY WEAKENING. FROM 200 TO 300 MILES IN ADVANCE OF THIS FRONT...THERE ARE CLUSTERS OF SHOWERS OVER THE SOUTHEASTERN INTERIOR. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .FIRE WEATHER... TEMPORARILY WARMER AND DRIER WEATHER IS EXPECTED SUNDAY OVER THE EASTERN INTERIOR...BUT WINDS WILL BE LIGHT AND MINIMUM RELATIVE HUMIDITY WILL BE ABOVE 50 PERCENT. ASIDE FROM THIS...MOSTLY CLOUDY AND DAMP WEATHER...INCLUDING SCATTERED SHOWERS MOST OF THE TIME...IS EXPECTED THROUGHOUT THE REALM FOR THE UPCOMING WEEK. THE ALASKA LIGHTNING DETECTION SYSTEM PICKED UP ONLY 20 STRIKES IN THE LAST 24 HOURS. THIS CONTRASTS WITH THE 2057 STRIKES FROM 6 AM AKDT THURSDAY TO 6 AM AKDT FRIDAY. && .HYDROLOGY... SOME RIVERS IN THE EASTERN INTERIOR ARE RISING...BUT ARE NOT EXPECTED TO APPROACH BANKFUL. MOST NORTHERN ALASKA RIVERS ARE AT RATHER LOW STAGES...SOME ARE STEADY AND A FEW ARE CONTINUING TO HAVE SLOWLY FALLING STAGES. THE SOUTHWESTERN INTERIOR...INCLUDING THE CENTRAL INTERIOR...THE LOWER KOYUKUK AND MIDDLE YUKON VALLEYS...AND ESPECIALLY THE UPPER KUSKOKWIM VALLEY...WILL GET MOST OF THE PRECIPITATION IN NORTHERN ALASKA NEXT TWO DAYS. WHILE THE RAINFALL RATE WILL BE LIGHT...ITS DURATION WILL BE FAIRLY LONG. THUS...SLOW AND STEADY RISES ON RIVERS IN THESE AREAS ARE EXPECTED...ALTHOUGH RIVER LEVELS WILL BE WELL UNDER BANKFUL. && .AFG WATCHES/WARNINGS/ADVISORIES... NONE. && $$ TF JUL 12 ______________________________________________________________________ PAFG - Reference: ['early morning polar orbiting satellite imagery shows scattered'] 031 FXAK69 PAFG 111309 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 509 AM AKDT SAT AUG 11 2012 .DISCUSSION... THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS FORECAST A CONTINUATION OF THE VERY WEAK CIRCULATION OVER NORTHERN ALASKA AND ITS COASTAL WATERS THROUGH NEXT WEEK. BOTH FORECAST A BROAD AREA OF HIGH PRESSURE ALOFT OVER THE ALASKA MAINLAND SOUTH OF THE ARCTIC CIRCLE TO VERY GRADUALLY SHIFT SOUTHWARD OVER THIS WEEKEND. BOTH MODELS FORECAST A WEAK LOW ALOFT TO FORM OVER THE EAST SIBERIAN SEA SUNDAY AND TO MOVE OVER THE SOUTHEASTERN CHUKCHI SEA SUNDAY NIGHT. A TROUGH OF LOW PRESSURE ALOFT EXTENDING SOUTHWARD FROM THE LOW TO SAINT LAWRENCE ISLAND IS FORECAST TO DEVELOP MONDAY NIGHT AND TUESDAY...AND THEN TO WEAKEN AS IT MOVES NORTHEASTWARD OVER THE ALASKAN ARCTIC TUESDAY NIGHT AND WEDNESDAY. SOUTHWESTERLY FLOW ALOFT IN ADVANCE OF THIS SYSTEM IS EXPECTED TO BRING SOME LIGHT RAIN TO NORTHWEST ALASKA DURING THE FIRST HALF OF NEXT WEEK. THE GFS MODEL FORECASTS ANOTHER LOW ALOFT TO MOVE OVER THE SOUTHEASTERN CHUKCHI SEA THURSDAY AND FRIDAY...AND WEAK HIGH PRESSURE ALOFT TO REDEVELOP OVER THE ALASKA MAINLAND SUNDAY AND SUNDAY NIGHT. MORE SUNNY LATE SUMMER WEATHER CAN BE EXPECTED IN MUCH OF THE REALM WITH THIS. TEMPERATURES ALOFT ARE NOT FORECAST TO BE VERY WARM...ONLY AROUND 50 DEGREES FAHRENHEIT NEAR THE 5000 FOOT LEVEL...SO AFTERNOON TEMPERATURES IN MOST OF THE INTERIOR SHOULD REMAIN IN THE 70S. THE RELATIVE HUMIDITY BRIEFLY DROPPED TO A RANGE OF 35 TO 40 PERCENT ON FRIDAY AFTERNOON AT SOME CENTRAL AND EASTERN INTERIOR LOCATIONS. SIMILAR VALUES ARE EXPECTED TODAY AND SUNDAY. SURFACE WINDS ARE EXPECTED TO CONTINUE TO BE QUITE LIGHT FOR THE NEXT SEVERAL DAYS THROUGHOUT THE INTERIOR. THE AIR MASS OVER THE INTERIOR REMAINS STABLE...ALTHOUGH EARLY MORNING WEATHER BALLOON DATA INDICATES THAT THE DEPTH OF THE SURFACE BASED MIXING LAYER THIS AFTERNOON WILL BE TYPICALLY 1000 TO 2000 FEET MORE THAN IT WAS YESTERDAY. ON FRIDAY...THE ALASKA LIGHTNING DETECTION SYSTEM DID NOT RECORD ANY LIGHTNING STRIKES IN ALASKA. THIS IS UNUSUAL DURING SUMMER IN INTERIOR ALASKA. ALL RIVERS IN NORTHERN ALASKA REMAIN AT LEVELS WELL BELOW BANKFUL. STAGES ON MOST NORTHERN ALASKA RIVERS ARE STEADY OR SLOWLY FALLING. TO SUM IT UP...A WEEK OF QUIET SUMMER WEATHER IS IN STORE FOR NORTHERN ALASKA. THE SOUTHERN EDGE OF THE PACK ICE IN THE CHUKCHI SEA RUNS WEST FROM BARROW. DURING THE PAST TWO WEEKS THERE HAS BEEN VERY LITTLE CHANGE IN THE CHUKCHI SEA ICE ALONG THE ALASKA ARCTIC COAST. THE ICE ALONG THE IMMEDIATE COAST FROM WAINWRIGHT TO BARROW CLEARED DURING THIS TIME. THIS MORNING THE NATIONAL WEATHER SERVICE OBSERVER AT BARROW ESTIMATES THE ICE EDGE IS 7 MILES OFFSHORE...WHERE IT HAS REMAINED FOR DAYS. IN THE BEAUFORT SEA FROM BARROW TO PRUDHOE BAY...ICE REMAINS...EXCEPT FOR SOME OPEN WATER WITHIN 20 TO 40 MILES OF SHORE. EAST OF PRUDHOE BAY...MOST WATERS ARE ICE FREE SOUTH OF 72 DEGREES NORTH LATITUDE...ALTHOUGH AREAS OF OPEN PACK ICE REMAIN WITHIN 40 MILES OF SHORE EARLY MORNING POLAR ORBITING SATELLITE IMAGERY SHOWS SCATTERED ALTOSTRATUS CLOUDS OVER MOST OF THE EASTERN AND NORTHERN INTERIOR...AND MOSTLY CLOUDY SKIES OVER THE WESTERN MAINLAND...AND OVERCAST LAYERED CLOUDS OVER THE ARCTIC. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .FIRE WEATHER... && .HYDROLOGY... && .AFG WATCHES/WARNINGS/ADVISORIES... NONE. && $$ TF AUG 12 ______________________________________________________________________ PAFG - Reference: ['early morning polar orbiting satellite imagery shows a large deck'] 910 FXAK69 PAFG 121410 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 610 AM AKDT SUN AUG 12 2012 .DISCUSSION... THE SATURDAY EVENING RUNS OF THE GFS AND NAM COMPUTER WEATHER FORECAST MODELS OFFER SIMILAR SOLUTIONS. HIGH PRESSURE ALOFT AND VERY WEAK CIRCULATION WILL PERSIST OVER THE INTERIOR THROUGH TONIGHT. AS EARLIER MODEL RUNS HAD FORECAST...THE NAM AND GFS RUNS FROM SATURDAY EVENING PREDICT A SHORT WAVE ALOFT TO MOVE EASTWARD...AND TO EXTEND FROM THE CHUKCHI SEA THROUGH BERING STRAIT AND OVER SAINT LAWRENCE ISLAND TONIGHT. A SIMILAR SHORT WAVE ALOFT IS FORECAST TO FOLLOW 24 HOURS LATER...REACHING THESE AREAS MONDAY NIGHT. THESE DEVELOPMENTS ARE EXPECTED TO BE ACCOMPANIED BY SOME LIGHT RAIN OVER NORTHWEST ALASKA DURING THE NEXT 3 DAYS. THE MODELS FORECAST LOW PRESSURE AT THE SURFACE TO DEVELOP OVER SIBERIA STARTING TONIGHT...AND TO GRADUALLY STRENGTHEN THROUGH TUESDAY NIGHT. ON WEDNESDAY...THE GFS FORECASTS A 984 MB LOW TO MOVE EASTWARD OVER CHUKOTKA. THIS LOOKS LIKE A REASONABLE FORECAST. THE SURFACE CHART FROM THE RUN BASED ON DATA FROM 10 PM AKDT SATURDAY INCLUDED A 992 MILLIBAR LOW WHICH HAD MOVED NORTHWARD AROUND 40 MPH OVER THE SEA OF OKHOTSK TO INLAND CHUKOTKA. A SYSTEM MOVING THIS RAPIDLY CAN BE EXPECTED TO CARRY SIGNIFICANT ENERGY. / NOTE THAT A SYSTEM WITH A LOT OF ENERGY DOES NOT NECESSARILY MOVE RAPIDLY. / THE MODELS FORECAST A SERIES OF SUCH LOWS TO MOVE NORTHEASTWARD OVER CHUKOTKA FOR THE NEXT 4 DAYS. THE INFLUX OF ENERGY...AS THAT PRESENTLY IN PROGRESS...CAN REASONABLY BE EXPECTED TO BRING MORE ACTIVE WEATHER TO NORTHWEST ALASKA BY MID WEEK THIS WEEK. THE GFS SURFACE FORECAST INDICATES THAT THE CIRCULATION OVER NORTHWEST ALASKA WILL REACH ITS MAXIMUM LEVEL FOR THE WEEK ON THIS WEDNESDAY. SOUTHERLY GALES THROUGH BERING STRAIT ARE POSSIBLE THIS WEDNESDAY. THE GFS MODEL FORECASTS STEADILY DIMINISHING CIRCULATION OVER NORTHERN ALASKA FROM THURSDAY THROUGH THE FOLLOWING TUESDAY. COOLER AIR AND LOW PRESSURE ALOFT ARE EXPECTED TO EXPAND OVER THE REALM DURING THE FIRST DAYS OF THE WEEK AFTER THIS ONE / STARTING MONDAY AUGUST 21. / THE GFS AND EUROPEAN FORECAST MODELS HAVE PRETTY SIMILAR PROJECTIONS FOR THIS...MORE SO THAN IS NORMALLY THE CASE. THE PERSISTENCE OF THE HIGH PRESSURE ALOFT WHICH HAS LINGERED OVER NORTHERN ALASKA FOR ABOUT A WEEK MAY TURN OUT TO BE GREATER THAN THE GFS FORECAST. IF SO...THE WEEK OF AUGUST 20 IN NORTHERN ALASKA WILL HAVE SCATTERED SHOWERS AND SEASONABLE TEMPERATURES. IF THE GFS FORECAST IS CLOSE TO THE REAL OUTCOME...THEN COOL AND SHOWERY WEATHER MAY BE EXPECTED. AFTER ALMOST A DAY OF FINE FLYING WEATHER...THE ARCTIC COAST IS HAVING AN OUTBREAK OF FOG AND LOW CLOUDS...AND THIS LOOKS AS THOUGH IT MAY LAST. THE SURFACE HIGH PRESSURE AND VERY WEAK WINDS ASSOCIATED WITH IT MAY BE PART OF THE EXPLANATION OF THIS. SOMEWHAT IMPROVED CONDITIONS ARE LIKELY OVER THE ALASKAN ARCTIC COASTAL ZONES AND THE INLAND COASTAL PLAIN STARTING TONIGHT AND MONDAY AS THE HIGH PRESSURE OVER THE ALASKAN ARCTIC COAST MOVES NORTHEASTWARD. THIS WILL BE ACCOMPANIED BY LIGHT BUT STEADY EASTERLY SURFACE WINDS OVER THE ALASKA ARCTIC COAST...A DEVELOPMENT WHICH OFTEN LIFTS VISIBILITY AND...TO SOME EXTENT...THE LOW CLOUDS THAT USUALLY ACCOMPANY IT. EARLY MORNING POLAR ORBITING SATELLITE IMAGERY SHOWS A LARGE DECK OF ALTOSTRATUS CLOUDS OVER THE FORTYMILE COUNTRY...THE EASTERN ALASKA RANGE...THE SOUTHERN YUKON FLATS AND THE MIDDLE TANANA VALLEY. THIS AREA OF CLOUDS HAS BEEN MORE PERSISTENT THAN HAD BEEN EXPECTED. THE WEAKNESS OF CIRCULATION IN THE HIGH PRESSURE ALOFT OVER THE REGION MAY BE PART OF THE EXPLANATION FOR THIS. OVER THE CENTRAL AND WESTERN INTERIOR THERE ARE LARGE AREAS OF CLEAR SKIES. THE MORNING WEATHER BALLOON RUNS AT FAIRBANKS AND MCGRATH SHOW THAT THE AIR MASS OVER THE INTERIOR HAS RETAINED ITS STABILITY. THE ALASKA LIGHTNING DETECTION SYSTEM DID NOT RECORD ANY LIGHTNING IN ALASKA ON FRIDAY AND SATURDAY. THUNDERSTORMS ARE NOT IN THE FORECASTS FOR THE NORTHERN ALASKA INTERIOR FOR TODAY OR FOR MONDAY. THE PACK ICE OFFSHORE BARROW CONTINUES TO HOLD. ON SATURDAY EVENING...THE OBSERVER AT THE NATIONAL WEATHER SERVICE OFFICE IN BARROW REPORTED ICE FREE WATERS FOR AT LEAST 9 MILES TO THE WEST. HOWEVER...THE NORTH AND NORTHWEST SECTORS HAD SIGNIFICANT ICE FROM 4 TO 5 MILES OFFSHORE FROM BARROW. SOME OF THIS ICE APPEARED TO BE MULTIYEAR ICE. EAST WINDS...WHICH FAVOR MOVEMENT OF THE ICE OUT TO SEA...ARE NOT EXPECTED OVER THE ALASKAN ARCTIC COAST FOR MORE THAN A DAY OR SO OUT OF THE NEXT WEEK. MOST OF THE TIME...THE WINDS ARE FORECAST TO BE SOUTH TO SOUTHWEST. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .FIRE WEATHER... AFTERNOON RELATIVE HUMIDITY AT A FEW INTERIOR STATIONS WAS A LOW AS 25 PERCENT...MOST LOCATIONS HAD MINIMUM RELATIVE HUMIDITY FROM 30 TO 40 PERCENT ON SATURDAY AFTERNOON. WINDS WILL CONTINUE TO BE VERY LIGHT THROUGHOUT NORTHERN ALASKA. THE AIR MASS OVER INTERIOR ALASKA REMAINS STABLE. THE ALASKA LIGHTNING DETECTION SYSTEM DID NOT REPORT ANY LIGHTNING ON SATURDAY. SLIGHTLY WARMER AND DRIER WEATHER IS EXPECTED IN THE INTERIOR OR MONDAY. VERY LITTLE PRECIPITATION IS EXPECTED IN THE INTERIOR FOR THE NEXT SEVERAL DAYS. && .HYDROLOGY... RIVERS THROUGHOUT THE REALM ARE WELL WITHIN THEIR BANKS. SMALL RISES ARE IN PROGRESS ON THE CANNING RIVER NEAR KAKTOVIK...THE OLD CROW RIVER NEAR ITS CONFLUENCE WITH THE PORCUPINE RIVER...AND THE YUKON RIVER AT DAWSON AND EAGLE. OTHER THAN THESE...NORTHERN ALASKA RIVERS ARE AT STEADY OR SLOWLY FALLING STAGES. THIS PATTERN IS EXPECTED TO CONTINUE THIS WEEK DUE TO THE LACK OF RAINFALL NEARLY EVERYWHERE. TEMPERATURES IN HIGHER ELEVATION SNOW FIELDS AND GLACIERS ARE EXPECTED TO BE NEAR OR SLIGHTLY COOLER THAN NORMAL...SO SNOW AND ICE MELT IN THE HIGHLANDS WILL BE WELL BELOW LEVELS WHICH COULD CAUSE HIGH WATER DOWNSTREAM. && .AFG WATCHES/WARNINGS/ADVISORIES... NONE. && $$ TF AUG 12 ______________________________________________________________________ PAFG - Reference: ['this mornings polar orbiting satellite imagery shows that the'] 217 FXAK69 PAFG 131407 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 607 AM AKDT MON AUG 13 2012 .DISCUSSION... AN END TO HE LONG PERIOD OF VERY QUIET WEATHER IN NORTHERN ALASKA IS NOW IN SIGHT. SURFACE ANALYSES OF THE RUSSIAN FAR EAST SHOW INCREASINGLY ENERGETIC LOW PRESSURE SYSTEMS MOVING NORTHWARD INTO THE CHUKCHI SEA. THIS SUPPORTS THE FORECASTS OF THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS...WHICH PREDICT THAT A SERIES OF ENERGETIC LOW PRESSURE SYSTEMS IN SIBERIA WILL CAUSE INCREASING SOUTH WINDS OVER NORTHWEST ALASKA STARTING TONIGHT...AND REACHING A PEAK WEDNESDAY AND WEDNESDAY NIGHT. DURING THIS TIME...SOUTHERLY GALES ARE EXPECTED FROM SAINT LAWRENCE ISLAND TO POINT HOPE. RAIN IS EXPECTED TO FALL FOR SEVERAL DAYS OVER THE NORTHWEST MAINLAND OF ALASKA THIS WEEK. FOLLOWING THIS...GRADUALLY WEAKENING CIRCULATION AND SCATTERED SHOWERS ARE EXPECTED TO BE THE RULE. AFTERNOON HIGH TEMPERATURES IN THE INTERIOR HAVE BEEN NEAR NORMAL...AND OVERNIGHT LOW TEMPERATURES HAVE BEEN ABOVE NORMAL. THE BIG CHANGES HAVE COME IN THE ARCTIC. SUNDAYS HIGH TEMPERATURES WERE ABOUT 10 DEGREES FAHRENHEIT ABOVE SATURDAYS. NEARLY ALL OF THE ALASKAN ARCTIC HAD AFTERNOON TEMPERATURES IN THE 50S AND 60S ON SUNDAY...A LEVEL WELL ABOVE NORMAL. THE NATIONAL WEATHER SERVICE OBSERVER AT BARROW REPORTS THAT THE SEA WEST OF BARROW IS ICE FREE TO THE WEST. A FEW PIECES OF ICE ARE TO THE NORTHWEST OF BARROW...AT AN ESTIMATED DISTANCE OF 8 MILES. TO THE NORTH OF BARROW...ONLY A FEW PIECES OF ICE ARE IN SIGHT...BUT ICE BLINK ON THE HORIZON IS EVIDENCE OF PACK ICE HOLDING BEYOND A DISTANCE OF 9 MILES FROM BARROW. SOUTHEAST TO SOUTHWEST WINDS ARE EXPECTED TO HOLD OVER THE ALASKAN ARCTIC COAST FOR THE REST OF THIS WEEK. THIS WIND REGIME WILL PREVENT SIGNIFICANT ONSHORE MOVEMENT OF THE ICE...AND MAY IN FACT AID AND ABET ITS MOVEMENT SEAWARD. THIS MORNINGS POLAR ORBITING SATELLITE IMAGERY SHOWS THAT THE VERY LONG LASTING DECK OF ALTOSTRATUS THAT HELD OVER THE SOUTHEASTERN INTERIOR ON SUNDAY HAS SHIFTED SOUTHEASTWARD. MOST OF THE FORTYMILE COUNTRY HAS CLEARED. SO HAS MOST OF THE ALASKA RANGE EAST OF THE TOK CUTOFF ROAD. SKIES OVER MOST OF THE INTERIOR AND THE ARCTIC EAST OF POINT LAY ARE CLEAR. SKIES ARE CLOUDY OVER THE BERING SEA COASTAL REGIONS...ESPECIALLY THE SEWARD PENINSULA AND THE SOUTHEASTERN CHUKCHI SEA. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .FIRE WEATHER... MINIMUM RELATIVE HUMIDITY IN INTERIOR ZONES WAS IN THE 30S PERCENT AT MANY LOCATIONS. A FEW HAD MINIMUM RELATIVE HUMIDITY REACH AS LOW AS 23 PERCENT. THE REMOTE AUTOMATIC WEATHER STATION AT THE ANGEL CREEK AUTOMATIC WEATHER STATION...AT AN ELEVATION OF 1100 FEET IN THE MIDDLE TANANA VALLEY...ON SUNDAY AFTERNOON...THE MINIMUM RELATIVE HUMIDITY WAS 23 PERCENT AND THE PEAK WIND GUST WAS 21 MPH. SO FAR...SURFACE WINDS DURING THE AFTERNOONS HAVE BEEN QUITE LIGHT. THIS IS EXPECTED TO CONTINUE TO BE THE CASE THROUGH TUESDAY. BRISK SOUTH WINDS / 10 TO 20 MPH / ARE EXPECTED IN THE FAR NORTHWEST INTERIOR STARTING WEDNESDAY...BUT THESE WILL COME IN CONJUNCTION WITH INCREASING CLOUDS...SOME RAIN...AND RISING RELATIVE HUMIDITY. && .HYDROLOGY... ALL NORTHERN ALASKA RIVERS ARE WELL WITHIN THEIR BANKS. NEARLY ALL ARE AT STEADY OR SLOWLY FALLING STAGES. STAGES ON THE KOYUKUK RIVER AT BETTLES HAVE COME DOWN 1.3 FEET IN THE PAST 5 DAYS. THE STAGE ON THE KOBUK RIVER AT KIANA HAS COME DOWN 1.8 FEET DURING THE PAST 7 DAYS. THERE HAVE BEEN SMALL RISES / A FEW INCHES / OF THE STAGES OF GOLDSTREAM CREEK NEAR FAIRBANKS...JUDY CREEK NEAR NUIQSUT AND THE PORCUPINE RIVER NEAR THE YUKON BORDER. THE YUKON RIVER AT EAGLE HAS COME UP 1.8 FEET IN THE PAST 24 HOURS. SNOW AND GLACIAL MELT IN HIGHLAND WATERSHEDS IS AT MODERATE LEVELS BECAUSE TEMPERATURES ALOFT HAVE NOT RISEN TO LEVELS WHICH CAUSE SIGNIFICANT MELT. AT THE 5000 FOOT LEVEL IN THE EASTERN INTERIOR...TEMPERATURES ARE FORECAST TO RISE AS FAR UP AS 51 DEGREES FAHRENHEIT AT MID WEEK. TEMPERATURES AT THIS ALTITUDE CAN RISE INTO THE 60S...A LEVEL AT WHICH CONSIDERABLE MELT WILL OCCUR. PRECIPITATION IN NORTHERN ALASKA IS EXPECTED TO BE INCONSEQUENTIAL EXCEPT ON SOUTH FACING HILLS IN THE NORTHWEST MAINLAND...WHICH COULD PICK UP AN INCH OF RAIN IN THE THREE DAY PERIOD / THIS TUESDAY THROUGH THURSDAY / AT THE MIDDLE OF THIS WEEK. && .AFG WATCHES/WARNINGS/ADVISORIES... NONE. && $$ TF AUG 12 ______________________________________________________________________ PAFG - Reference: ['lisburne...last night. this mornings polar orbiting satellite'] 600 FXAK69 PAFG 141430 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 630 AM AKDT TUE AUG 14 2012 .DISCUSSION... CIRCULATION OVER NORTHWEST ALASKA HAS INCREASED SIGNIFICANTLY DURING THE PAST 24 HOURS...SOUTH WINDS NEAR BERING STRAIT HAVE REACHED SPEEDS OF 20 TO 30 MPH. A SERIES OF PROGRESSIVELY STRONGER LOW PRESSURE SYSTEMS OVER THE RUSSIAN FAR EAST HAVE BROUGHT THIS CHANGE. A 984 MILLIBAR LOW CENTER IS FORECAST TO BE NEAR 160 DEGREES EAST LONGITUDE AND 67 DEGREES NORTH LATITUDE LATE THIS EVENING. BRISK SOUTHWEST FLOW ALOFT HAS DEVELOPED OVER THE NORTHWEST HALF OF THE REALM IN ADVANCE OF THIS SYSTEM AND IS EXPECTED TO CONTINUE THROUGH EARLY FRIDAY. HIGH PRESSURE ALOFT IS FORECAST TO HOLD OVER THE SOUTHEAST HALF OF NORTHERN ALASKA THROUGH EARLY FRIDAY. DRY AND WARM WEATHER WILL CONTINUE THERE. A SHORT WAVE ALOFT IS EXPECTED TO MOVE FROM THE GULF OF ALASKA TO THE UPPER TANANA VALLEY AND THE FORTYMILE COUNTRY ON FRIDAY. THIS COULD CREATE CONDITIONS FAVORABLE FOR THUNDERSTORMS ON FRIDAY. OFFSHORE FLOW OVER THE ALASKAN ARCTIC BROUGHT NEAR RECORD HIGH TEMPERATURES THERE ON MONDAY. MORE NORMAL...ONSHORE WINDS WILL DEVELOP FRIDAY AND SATURDAY...AND BRING AFTERNOON TEMPERATURES DOWN 10 TO 20 DEGREES FROM WHERE THEY WERE SUNDAY AND MONDAY. COASTAL FOG HAS RETURNED TO PRUDHOE BAY AND BARTER ISLAND THIS MORNING...AND THOUGH IT WILL CLEAR LATER TODAY...IT IS SYMPTOMATIC OF THE BEGINNING OF A COOLING TREND. A 1000 MILLIBAR LOW MOVED NORTHEASTWARD...PAST CAPE LISBURNE...LAST NIGHT. THIS MORNINGS POLAR ORBITING SATELLITE IMAGERY SHOWS THE WEATHER FRONT ASSOCIATED WITH THIS LOW EXTENDING FROM THE WESTERN BROOKS RANGE TO NOME. SKIES OVER THE FAR EASTERN ARCTIC AND THE SOUTHEASTERN HALF OF THE INTERIOR ARE CLEAR. COASTAL HAZARD POTENTIAL DAYS 3 AND 4. WIND DRIVEN RISES IN WATER LEVELS FROM 2 TO 2.8 FEET ABOVE NORMAL TIDE LEVELS ARE EXPECTED ON THE NORTON SOUND AND SAINT LAWRENCE ISLAND COASTS FROM WEDNESDAY EVENING THROUGH THURSDAY. WAVES FROM 6 TO 9 FEET OFFSHORE WILL DIMINISH SOME AS THEY BREAK ON SHORE. ALTHOUGH THERE WILL BE ELEVATED SURF WEDNESDAY AFTERNOON THROUGH THURSDAY...CONDITIONS DO NOT APPEAR SERIOUS ENOUGH FOR A HIGH SURF ADVISORY. && .FIRE WEATHER... MINIMUM RELATIVE HUMIDITY IN THE SOUTHEASTERN INTERIOR RANGED FROM 25 TO 35 PERCENT AT MOST REPORTING STATIONS...BUT A FEW REPORTED VALUES FROM 19 TO 24 PERCENT. WARM AND DRY WEATHER IS EXPECTED TO CONTINUE OVER THE SOUTHEASTERN INTERIOR FOR THE REST OF THIS WEEK. WINDS DURING THE AFTERNOONS HAVE BEEN LIGHT...BUT SOUTHWEST WINDS FROM 10 TO 15 MPH ARE EXPECTED IN MUCH OF THE INTERIOR WEDNESDAY AND THURSDAY. NO LIGHTNING WAS OBSERVED BY THE ALASKA LIGHTNING DETECTION SYSTEM ON MONDAY. THE AIR MASS OVER NORTHERN ALASKA REMAINS STABLE...NO THUNDERSTORMS ARE EXPECTED TODAY. && .HYDROLOGY... CLOSE TO ONE INCH OF RAIN HAS FALLEN AT KIVALINA IN THE PAST 24 HOURS. RAINFALL TOTALS IN THE PAST 24 HOURS OVER OTHER PARTS OF NORTHWEST ALASKA ARE MOSTLY FROM ONE QUARTER TO ONE HALF OF AN INCH. THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS FORECAST FROM 1 TO 3 INCHES OF RAIN OVER THE SOUTHWEST FACING SLOPES OF THE WESTERN BROOKS RANGE OVER THE NEXT 48 HOURS. SO FAR...THE RESPONSE ON THE RIVERS HAS BEEN SMALL. THE WULIK RIVER AND IKALUKROK CREEK...BOTH NEAR THE RED DOG MINE NORTH OF KOTZEBUE...BEGAN TO RISE MONDAY AFTERNOON. STAGES ON THEM ARE UP SEVERAL INCHES. THE STAGE ON THE MEADE RIVER NEAR ATQASUK HAS COME UP ABOUT SEVEN INCHES IN THE PAST 24 HOURS...AND APPEARS TO BE CRESTING. HOWEVER...THE AMOUNT OF RAINFALL FORECAST BY THE NAM AND GFS MODELS IS SIGNIFICANT. EVEN IF ONLY HALF OF THE FORECAST RAINFALL IS OBSERVED...SMALL STREAMS COULD RISE CLOSE TO BANK FULL BY WEDNESDAY EVENING. RISING STAGES ON THE MAIN STEMS OF LARGER RIVERS WILL FOLLOW. DOWN SLOPE FLOW OVER HIGHER TERRAIN IN NORTHWEST ALASKA WILL RESULT IN MUCH SMALLER AMOUNTS OF PRECIPITATION ON NORTHEAST FACING SLOPES. OUTSIDE OF NORTHWEST ALASKA...ALL RIVERS IN THE REALM ARE AT STEADY OR SLOWLY FALLING STAGES WELL BELOW BANK FULL. && .AFG WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY FOR PKZ210-PKZ220-PKZ225. BRISK WIND ADVISORY FOR PKZ235. && $$ TF AUG 12 ______________________________________________________________________ PAFG - Reference: ['the morning polar orbiting satellite imagery shows an increasingly'] 034 FXAK69 PAFG 061353 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 553 AM AKDT THU SEP 6 2012 .DISCUSSION... THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS ARE IN AGREEMENT. STRONG LOW PRESSURE ALOFT AND AT THE SURFACE...NOW SITUATED OVER THE EASTERN BEAUFORT SEA...IS EXPECTED TO MOVE EASTWARD AT A SPEED OF 10 TO 15 MPH. IT IS FORECAST TO WEAKEN SLOWLY. WINDS ALOFT OVER ALL OF THE REALM SAVE THE NORTHWEST ARE FAIRLY STRONG OUT OF THE SOUTHWEST. THIS IS A GOOD PATTERN FOR WIDESPREAD RAIN...EXCEPT IN THE SOUTHEASTERN INTERIOR WHICH HAS DRY DOWN SLOPE FLOW OFF THE ALASKA RANGE. THE WESTERLIES ARE FORECAST TO WEAKEN TONIGHT AND FRIDAY. HOWEVER...THE WESTERLY CIRCULATION OVER THE BEAUFORT SEA AND ADJACENT COASTS WILL CONTINUE THROUGH SATURDAY. THE FORECAST MAPS LOOK LIKE A LATE OCTOBER SCENE. THE FAIRBANKS WEATHER RADAR MEASURED WINDS ALOFT HAVE BEEN SOUTHWEST TO 45 MPH AT THE 5000 FOOT LEVEL ALL NIGHT. THESE ARE EXPECTED TO GRADUALLY DIMINISH TODAY. SIGNIFICANT COOLING ALOFT IS FORECAST OVER THE ARCTIC SLOPE AND THE NORTHWEST INTERIOR ON THURSDAY NIGHT THROUGH FRIDAY NIGHT. BASED ON THIS...SNOWFALL ACCUMULATION IS IN THE WESTERN ARCTIC ZONES. A LOW PRESSURE SYSTEM NOW A BIT WEST OF THE PRIBILOFS IS FORECAST TO MOVE ASHORE OVER THE SOUTHERN YUKON DELTA TONIGHT. THIS WILL BE THE FINAL WESTERN AND ARCTIC ALASKA LOW IN THE SERIES WHICH HAS BEEN IN PROGRESS FOR THE PAST WEEK. WEAK CIRCULATION IS EXPECTED THROUGHOUT THE REALM / THE EASTERN ARCTIC EXCEPTED / BY FRIDAY AFTERNOON. THE MEDIUM RANGE COMPUTER FORECAST MODELS PREDICT A PICKUP IN CIRCULATION OVER THE SOUTHWEST MAINLAND STARTING MONDAY...AND INCREASING FURTHER LATE NEXT WEEK. IF THIS WORKS OUT...MILDER TEMPERATURES WILL DEVELOP OVER THE INTERIOR AND SOUTHWEST ALASKA STARTING IN THE MIDDLE OF NEXT WEEK. THE MORNING POLAR ORBITING SATELLITE IMAGERY SHOWS AN INCREASINGLY DISORGANIZED MASS OF CLOUDS OVER THE ALASKA MAINLAND. THE HIGHEST CLOUDS ARE IN THE LEE / NORTH OF / THE ALASKA RANGE FROM DENALI PARK TO THE CANADA BORDER. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .HYDROLOGY... ALL NORTHERN ALASKA RIVERS ARE WELL BELOW BANKFULL. THERE ARE SMALL RISES IN PROGRESS SOME RIVERS IN THE NORTHEAST PART OF THE REALM. SEVERAL ARCTIC SLOPE RIVERS HAD TEXTBOOK CRESTS DURING THE FIRST FIVE DAYS OF THE MONTH...THE MOST PRONOUNCED WAS ON THE IKPIKPUK RIVER...LOCATED BETWEEN BARROW AND UMIAT. THE WULIK RIVER EAST OF KIVALINA CONTINUES TO SLOWLY FALL. BY WAY OF HISTORY...THE WULIK HAD ITS HIGHEST RECORDED CREST ON RECORD ON AUGUST 25-26...3 FEET ABOVE ANY OBSERVED LEVEL IN ABOUT 20 YEARS OF RECORDS. THE RED DOG MINE...ABOUT 40 MILES UPSTREAM ON THE WULIK RIVER FROM KIVALINA...AT AN ELEVATION AROUND 1000 FEET...HAD A TOTAL AUGUST RAINFALL OF 15.25 INCHES. NO OTHER WEATHER STATION IN ALASKA HAD MORE RAIN THAN THIS...EVEN IN SOUTHEAST ALASKA. RETURNING TO THE PRESENT...THE HEAVIEST RAINFALL IN NORTHERN ALASKA DURING THE NEXT TWO DAYS WILL BE IN THE KOYUKUK...MIDDLE YUKON AND UPPER KUSKOKWIM VALLEYS...IN ADVANCE OF A TROUGH OF LOW PRESSURE ALOFT COMING IN FROM THE BERING SEA COAST. && .AFG WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FOR AKZ226 UNTIL 6AM. SMALL CRAFT ADVISORY FOR PKZ200-PKZ245. && $$ TF SEP 12 ______________________________________________________________________ PAFG - Reference: ['this mornings polar orbiting satellite imagery shows breaks in'] 279 FXAK69 PAFG 071358 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 558 AM AKDT FRI SEP 7 2012 .DISCUSSION... THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS HAVE SIMILAR PROJECTIONS THROUGH SATURDAY NIGHT. THE ENERGY LEVEL OF THE WEATHER OVER NORTHERN ALASKA IS COMING DOWN...AND LOOKS LIKE IT WILL BE LOW KEY UNTIL MID WEEK NEXT WEEK OR BEYOND. THE STRONG LOW PRESSURE SYSTEM NOW CENTERED 200 MILES NORTH OF SACHS HARBOR...IN THE FAR NORTHEASTERN BEAUFORT SEA...IS GRADUALLY WEAKENING AND CONTINUING TO MOVE NORTHEASTWARD. WEST TO NORTHWEST GALES IN THE SOUTH QUADRANT OF THIS SYSTEM ARE FORECAST TO WEAKEN LATE THIS AFTERNOON AS THE LOW PULLS AWAY. THE INFLUX OF COLD AIR TO THE WEST OF THIS LOW IS REFLECTED IN THE SNOW AT WAINWRIGHT AND BARROW...WHICH HAS BEEN FALLING SINCE THURSDAY MORNING. THE MORNING WEATHER BALLOON DATA SHOWS THAT COOLING ALOFT HAS OCCURRED NEARLY EVERYWHERE OVER NORTHERN ALASKA. THE AIR MASS IS SLIGHTLY UNSTABLE OVER MUCH OF THE REALM...A CONDITION FAVORABLE FOR SHOWERS. YESTERDAY...THE WEB CAMS AT THE EIELSON VISITORS CENTER IN DENALI NATIONAL PARK SHOWED ABOUT 4 INCHES OF NEW SNOW...WHICH WAS ENOUGH TO CLOSE THE ROAD INTO THE CENTER FOR SEVERAL HOURS. A WEAK LOW WHICH ORIGINATED OVER THE GULF OF ANADYR THURSDAY MORNING IS NOW JUST NORTH OF NUNIVAK ISLAND AND CONTINUING TO TRACK SOUTHEASTWARD AT 30 MPH. ALTHOUGH THERE IS LITTLE WIND WITH THIS SYSTEM...IT IS BRINGING SOME SHOWERS TO THE YUKON DELTA AND THE SOUTHWESTERN INTERIOR. THIS MORNINGS POLAR ORBITING SATELLITE IMAGERY SHOWS BREAKS IN THE OVERCAST FORMING OVER MUCH OF THE REALM...ESPECIALLY IN THE EASTERN INTERIOR. THERE IS AN ARC OF HIGH CLOUDS EXTENDING FROM THE SOUTHEASTERN BEAUFORT SEA TO THE EASTERN BROOKS RANGE. THESE CLOUDS ARE ASSOCIATED WITH THE LARGE BEAUFORT SEA LOW PRESSURE SYSTEM. THE CLOUD PATTERNS OVER THE REMAINDER OF NORTHERN ALASKA ARE RATHER DISORGANIZED. THE MEDIUM RANGE COMPUTER WEATHER FORECAST MODELS AGREE WELL THROUGH NEXT WEDNESDAY...PROJECTING A LARGE AND SLACK AREA OF LOW PRESSURE AND COOL AIR ALOFT OVER THE ALASKA MAINLAND. THIS SEEMS LIKE A REASONABLE FORECAST. ALTHOUGH THE DETAILS IN THE MODELS DIFFER AFTER NEXT WEDNESDAY...THE GFS AND EUROPEAN FORECAST MODELS BOTH PREDICT A SOUTHERLY INFLUX OF MILDER AIR ALOFT OVER SOUTHWEST ALASKA STARTING NEXT FRIDAY. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .HYDROLOGY... AFTER THE RECENT RAINFALL...TYPICALLY FROM ONE HALF TO ONE INCH OVER TWO DAYS...THE KOYUKUK RIVER IS CRESTING TODAY...AT STAGES COMFORTABLY BELOW BANKFULL. THE PORCUPINE RIVER IN THE FAR NORTHEASTERN INTERIOR IS CRESTING. ALL RIVERS IN NORTHERN ALASKA ARE WELL BELOW BANKFULL. NO SIGNIFICANT PRECIPITATION IS FORECAST FOR THE NEXT FIVE DAYS OR MORE. && .AFG WATCHES/WARNINGS/ADVISORIES... HIGH SURF ADVISORY FOR AKZ203-AKZ204. SMALL CRAFT ADVISORY FOR PKZ210-PKZ235-PKZ240. GALE WARNING FOR PKZ245. && $$ TF SEP 12 ______________________________________________________________________ PAFG - Reference: ['polar orbiting satellite imagery has shown the weather front'] 278 FXAK69 PAFG 162224 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 224 PM AKDT SUN SEP 16 2012 .DISCUSSION... THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS HAVE THE SAME SOLUTION FOR THE PATH AND STRENGTH OF THE STRONG LOW PRESSURE SYSTEM NOW MOVING NORTH IN KUSKOKWIM BAY. INCREASED SPEED OF ITS NORTHWARD MOVEMENT WILL CARRY IT TO BARROW AT 10 AM MONDAY...AND THEN SLOWLY WESTWARD TO 200 MILES NORTH OF POINT LAY BY TUESDAY AFTERNOON. CIRCULATION AROUND THIS LOW IS FORECAST TO WEAKEN THROUGH TUESDAY. A SMALLER LOW NEAR WRANGEL ISLAND WILL DISSIPATE SUN NIGHT. A LOW WILL DEVELOP NEAR PRUDHOE BAY SUN NIGHT AND MOVE TO 100 MILES NORTHEAST OF BARROW BY 4PM MON AND THEN DRIFT WEST. A SECONDARY LOW IS FORECAST TO MOVE NORTHWARD THROUGH THE PRIBILOF ISLAND WATERS MONDAY EVENING AND TO REACH THE YUKON DELTA TUESDAY. CIRCULATION AROUND THIS LOW IS NOT AT ALL AS STRONG AS CIRCULATION AROUND THE FIRST LOW. THE SECONDARY LOW IS FORECAST TO WEAKEN THROUGH TUESDAY. THE ENERGY LEVEL OF WINDS AT THE SURFACE AND ALOFT OVER NORTHERN ALASKA WILL LESSEN CONSIDERABLY BY TUESDAY AND IS FORECAST BY THE MEDIUM RANGE MODELS TO CONTINUE AT A LOW LEVEL UNTIL NEXT WEEKEND...WHEN A NEW NORTH PACIFIC LOW IS PROJECTED TO MOVE NORTHWARD INTO SOUTHWEST ALASKA. BEYOND THIS TIME...THE FORECAST UNCERTAINTY IS TOO HIGH FOR MUCH OF A CONFIDENCE FACTOR TO THE FORECASTS. THIS IS TO BE EXPECTED. THE DOWN SLOPE WINDS OVER THE ALASKA RANGE...TO THE EAST OF TODAYS STRONG LOW PRESSURE SYSTEM...ARE HIGH. THE FAIRBANKS RADAR IS NOW MEASURING SOUTH WINDS TO 100 KNOTS / 115 MPH. / THE HAZE...FROM BLOWING DUST...HAS BEEN VISIBLE TO THE DISTANT SOUTH OF FAIRBANKS SINCE SUNRISE. THE VERY LARGE CLOUD SHIELD IN ADVANCE OF THE BRISTOL BAY LOW IS STARTING TO DIMINISH IN EXTENT. THE THICKEST CLOUDS OVER THE REALM ARE NOW OVER THE NORTHERN INTERIOR AND THE ARCTIC. INFRARED SATELLITE IMAGERY INDICATES CLOUD TOP TEMPERATURES NEAR -60 DEGREES C...WHICH TODAY IS AT AN ALTITUDE NEAR 35 THOUSAND FEET. THE WEATHER FRONT ASSOCIATED WITH THIS IS STRONGLY DEFINED ON SATELLITE IMAGERY. THE FRONT IS WRAPPED AROUND THE YUKON DELTA AND EXTENDS THROUGH GALENA THROUGH 50 DEGREES NORTH LATITUDE / 150 DEGREES WEST...WHICH IS ABOUT 700 MILES SOUTH OF ANCHORAGE. THIS FEATURE WILL BEGIN TO LOSE STRENGTH...BUT NOT UNTIL TONIGHT. POLAR ORBITING SATELLITE IMAGERY HAS SHOWN THE WEATHER FRONT WRAPPED AROUND THE WRANGEL ISLAND LOW ADVANCING SOUTHWESTWARD. CIRCULATION AROUND THIS LOW IS NOT TOO STRONG...BUT HAS NOT LOST WHAT STRENGTH IT DOES HAVE DURING THE DAY TODAY. THERE ARE LARGE BREAKS IN THE OVERCAST WHICH HAVE DEVELOPED OVER THE UPPER TANANA VALLEY AND THE FORTYMILE COUNTRY TODAY. AND THERE IS A CLEAR ZONE ABOUT 50 MILES WIDE BEHIND THE WEATHER FRONT ASSOCIATED WITH THE BRISTOL BAY LOW. AHEAD OF THIS FRONT...SOME HEAVY RAIN HAS FALLEN IN THE ALASKA RANGE...MOSTLY ON THE SOUTH SIDE...AND IN THE UPPER KUSKOKWIM VALLEY. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .HYDROLOGY... SOME MODERATE RAIN IN ADVANCE OF THE BRISTOL BAY LOW FRONT. SOME 24 HOUR RAINFALL TOTALS ARE... PHELAN CREEK NEAR PAXON................1.35 INCHES RICHARDSON HIGHWAY NEAR TRIMMS CAMP....3.99 FLAT...................................1.46 MCGRATH................................1.03 STREAMS IN THESE AREAS ARE AT LOW STAGES...SO NO PROBLEMS WITH HIGH WATER ARE EXPECTED. && .AFG WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FOR AKZ227. HIGH WIND WARNING FOR AKZ223-AKZ225-AKZ226. SMALL CRAFT ADVISORY FOR PKZ225-PKZ230-PKZ235-PKZ240-PKZ245. GALE WARNING FOR PKZ200-PKZ210-PKZ220-PKZ225-PKZ230-PKZ235- PKZ240-PKZ245. && $$ TF SEP 12 ______________________________________________________________________ PAFG - Reference: ['polar orbiting satellite imagery shows a low pressure circulation'] 495 FXAK69 PAFG 180050 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 450 PM AKDT MON SEP 17 2012 .DISCUSSION... A SERIES OF ACTIVE LOW PRESSURE SYSTEMS MOVING NORTHWARD FROM THE CENTRAL PACIFIC UP TO THE BERING SEA COAST OF THE ALASKA MAINLAND WILL CONTINUE TO BRING ACTIVE WEATHER TO MUCH OF THE REALM...MAINLY THE ALASKA RANGE AND IN THE WEST. THE FIRST IN THE SERIES IS A WEAKENING LOW ABOUT 100 MILES NORTH OF BARROW. THIS SYSTEM BROUGHT STRONG WINDS TO THE ARCTIC AND NORTHWEST COASTAL WATERS...THE ARCTIC OFFSHORE WATERS...AND A GOOD PORTION OF THE INTERIOR. THE FAIRBANKS WEATHER RADAR HAS BEEN OBSERVING WELL DEFINED PLUMES OF BLOWING SNOW OFF THE ALASKA RANGE MOUNTAINS...FROM MOUNT MCKINLEY SINCE 7 PM SATURDAY...AND FROM MOUNT HAYES SINCE 1 PM THIS AFTERNOON. SUCH FEATURES ARE RARELY SEEN ON THIS RADAR...AND THEY REFLECT STRONG WINDS ACROSS THE MOUNTAINS. THESE PLUMES ARE NOT DISCERNIBLE ON INFRARED SATELLITE IMAGERY...BUT ARE EASILY SEEN ON VISIBLE IMAGERY. THE SECOND LOW IN THE SERIES IS MOVING THROUGH THE EASTERN ALEUTIANS NOW AND WILL REACH NUNIVAK ISLAND TUESDAY AFTERNOON. THIS SYSTEM WILL BE RELATIVELY WEAK COMPARED TO ITS PREDECESSOR. THE THIRD LOW IN THE SERIES IS NOT YET FIRMLY IN HAND...BUT THE GFS COMPUTER WEATHER FORECAST MODEL PROJECTS IT TO MOVE AT A HIGH SPEED...ABOUT 70 / SEVENTY / MPH...NORTHWARD OUT OF THE PACIFIC TO REACH THE ALASKA PENINSULA TUESDAY EVENING. AGAIN...SATELLITE IMAGERY HAS NOT YET DEFINED A CLEAR PATTERN THAT SUCH A LOW PRESSURE SYSTEM MUST HAVE TO BE CREDIBLE. HENCE...THE CONFIDENCE FACTOR IS NOT HIGH YET. IT IS CLEAR THAT THIS SYSTEM COULD BE THE ONE MOST CRITICAL TO NORTHERN ALASKA WEATHER FOR THE REST OF THIS WEEK. THE COMMONLY USED TERM APPLIED TO OUR THIRD LOW IS... A PINEAPPLE EXPRESS... MEANING THAT ITS PATTERN INCLUDES STRONG FLOW ALOFT FROM THE PACIFIC NEAR HAWAII STRAIGHT NORTH TO THE ALASKA MAINLAND. THE GFS COMPUTER WEATHER FORECAST MODEL FORECASTS THE SURFACE LOW TO STRENGTHEN...BUT NOT TO A GREAT EXTENT. SINCE THE LOW IS FORECAST TO MOVE OVER LAND ONCE IT REACHES ALASKA...IT WILL NOT HAVE THE FLUX OF ENERGY FROM THE OCEAN TO FUEL ITS POWER. THE IMPORTANT PART OF THE PATTERN IS THE COMPRESSION OF FLOW OVER THE ALASKA RANGE STARTING TUESDAY NIGHT AND CONTINUING INTO WEDNESDAY. THIS IS THE BASIS OF THE HIGH WIND WATCH FOR ZONES 223...225...226 FOR ALL DAY WEDNESDAY. THE STRONG INFLUX OF MOISTURE FROM THE SOUTH BROUGHT SIGNIFICANT SNOWFALL TO THE BROOKS RANGE HIGHLANDS. SIX INCHES OF NEW SNOW WAS REPORTED IN ATIGUN PASS THIS AFTERNOON. INDEED...THIS AFTERNOONS POLAR ORBITING SATELLITE IMAGERY SHOWS A LOW PRESSURE CIRCULATION AREA ALOFT OVER THE CENTRAL BROOKS RANGE. SUCH MEDIUM SIZED WEATHER FEATURES SUCH AS THIS ONE CAN BRING SIGNIFICANT PRECIPITATION...EITHER RAIN OR SNOW. THIS ONE HAS DONE SO. THIS AFTERNOONS VISIBLE SATELLITE IMAGERY ALSO SHOWS EXTENSIVE AREAS IN THE BROOKS RANGE COVERED BY SNOW. ANOTHER SIGNIFICANT FEATURE OF THE WEATHER THAT THE THE THIRD LOW IS EXPECTED TO BRING TO THE INTERIOR IS WARM TEMPERATURES...INTO THE 60S LATER THIS WEEK. THE MEDIUM RANGE FORECAST MODELS PREDICT ONGOING MILD WEATHER THROUGHOUT THE REALM FOR THE NEXT 10 DAYS OR SO. THE SNOW COVER IN THE BROOKS RANGE NOTHWITHSTANDING...REAL WINTER IS...FOR NOW...FAR AWAY FROM NORTHERN ALASKA. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE. WINDS OVER THE BERING AND CHUKCHI SEA COAST WILL MOSTLY BE FROM THE NORTH...A DIRECTION OF WIND THAT DISFAVORS HIGH TIDES AND SURF...EXCEPT FOR THE NORTH SHORE OF SAINT LAWRENCE ISLAND. && .HYDROLOGY... HEAVY RAIN THAT FELL IN THE ALASKA RANGE ON SATURDAY THROUGH SUNDAY WAS INTERCEPTED MAINLY ON THE SOUTH SIDE OF THE MOUNTAINS. ONLY A SMALL CREST -- LESS THAN ONE FOOT -- WAS OBSERVED ON PHELAN CREEK NEAR PAXON. .FIRE WEATHER... ON SUNDAY...THE GREY HAZE BETWEEN FAIRBANKS AND THE ALASKA RANGE WAS BLOWING DUST OFF THE MOUNTAINS AND THEIR NORTHERN FOOTHILLS. THE WIND QUICKLY FANNED THE DRY CREEK FIRE INTO RENEWED RAPID GROWTH...THIS AFTER WEEKS OF GENTLE SMOLDERING. SMOKE WAS RAPIDLY BLOWN NORTHWARD INTO FAIRBANKS SUNDAY EVENING. THEN...LATE SUNDAY NIGHT AND BEFORE SUNRISE THIS MORNING...THERE WAS A LARGE DARK RED DOME OVER THE THE FIRE. SUCH A WILDFIRE EVENT IS VERY RARE IN ALASKA. THE RESUMPTION OF HIGH WINDS THROUGH THE ALASKA RANGE ON WEDNESDAY COULD BRING A RESUMPTION TO THE DRY CREEK FIRE. && .AFG WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY FOR PKZ200-PKZ215-PKZ220-PKZ240-PKZ245. WIND ADVISORY FOR AKZ223-AKZ225-AKZ226. HIGH WIND WATCH FOR AKZ223-AKZ225-AKZ226. && $$ TF SEP 12 ______________________________________________________________________ PAFG - Reference: ['polar orbiting satellite imagery today has shown slightly granular'] 649 FXAK69 PAFG 192358 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 358 PM AKDT WED SEP 19 2012 .DISCUSSION... THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS ARE COMING INTO BETTER AGREEMENT THAN THEY HAVE BEEN IN THE LAST SEVERAL DAYS. DURING HIGH ENERGY CIRCULATION OVER ALASKA AND THE NORTHEAST PACIFIC SUCH DIVERGENCE IS PRONE TO HAPPEN. A STRONG AREA OF HIGH PRESSURE ALOFT IS FORECAST BY THE MODELS TO HOLD OVER THE WESTERN LOWER 48 STATES AND NORTHWEST CANADA FOR THE REST OF THIS WEEK. BY MID WEEK NEXT WEEK...A BROAD AREA OF LOW PRESSURE AND WEAK CIRCULATION ALOFT IS FORECAST TO DEVELOP OVER THE ALASKA MAINLAND. SOMEWHAT COOLER AND DEFINITELY QUIETER WEATHER IS EXPECTED NEXT WEEK. THE AXIS OF THE STRONG NORTHWARD FLOWING JET STREAM FROM 33 DEGREES NORTH LATITUDE 160 DEGREES WEST LONGITUDE HAS SHIFTED SLIGHTLY TO THE EAST TODAY. THE BAND OF INCOMING CLOUDS ASSOCIATED WITH THIS JET STREAM WAS 500 MILES WIDE ON TUESDAY AFTERNOON...AND HAS THINNED DOWN TO LESS THAN 300 MILES WIDE NOW. THIS MEANS THAT MOST OF THE TRANSFER OF ENERGY WITH THIS SYSTEM HAS TAKEN PLACE. THE STRONG FLOW ALOFT WILL TAKE SOME TIME TO DIMINISH. THIS POINT WILL NOT BE REACHED UNTIL THE END OF THE WEEKEND. HOWEVER...THE STRONG WINDS NEAR THE SURFACE WILL DIMINISH TONIGHT. THE DEVELOPMENT OF A NEW SURFACE LOW PRESSURE SYSTEM NORTH OF BARTER ISLAND IS A HIGH CONFIDENCE FORECAST BASED ON MUCH PAST EXPERIENCE. WEST WINDS 20 TO 30 MPH...WITH GUSTS TO 40 MPH IN THE MORNING...ARE EXPECTED ON THE EASTERN BEAUFORT SEA COAST OF ALASKA ON THURSDAY. THESE WINDS WILL BE FROM THE WEST TO WEST SOUTHWEST...WHICH MEANS THERE WILL BE JUST ENOUGH OF AN OFFSHORE COMPONENT TO THE WIND TO PRECLUDE SIGNIFICANT SURF COMING UP ASHORE. THE WIND PROFILER DATA FROM TALKEETNA AND THE FAIRBANKS RADAR SHOW SOUTHEAST WINDS IN THE LOWEST 5 THOUSAND FEET HAVE INCREASED A LITTLE OVER THE SOUTHERN INTERIOR. THE WINDS WILL BEGIN TO DIMINISH LATER THIS EVENING. THIS PROCESS WILL BE GRADUAL. POLAR ORBITING SATELLITE IMAGERY TODAY HAS SHOWN SLIGHTLY GRANULAR CLOUDS OVER THE WESTERN THIRD OF THE REALM. THESE REFLECT A VERY SLIGHTLY UNSTABLE AIR MASS...A FEATURE THAT IS BORNE OUT BY THE WEATHER BALLOON DATA FROM MCGRATH...FAIRBANKS...NOME AND KOTZEBUE THIS MORNING. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .HYDROLOGY... PRECIPITATION HAS BEEN SIGNIFICANT IN THE ALASKA RANGE...BUT ONLY ON THE SOUTH SIDE. THE NORTH SIDE AND THE EASTERN AND CENTRAL INTERIOR HAVE HAD VERY LITTLE OR NO RAIN. THE WESTERN INTERIOR AND THE WESTERN COASTAL ZONES HAVE HAD SOME LIGHT RAIN...BUT NOWHERE NEAR ENOUGH TO BRING UP STREAMS AND RIVERS. .FIRE WEATHER... THE STRONG CHINOOK WIND OVER THE ALASKA RANGE HAS BROUGHT AFTERNOON RELATIVE HUMIDITY DOWN JUST BELOW 40 PERCENT AT A COUPLE OF EASTERN INTERIOR REPORTING STATIONS. BRISK WINDS HAVE NOT REACHED DOWN INTO THE VALLEYS WHERE THE HUMIDITY IS LOW. ALL OF THIS WILL END THIS EVENING...AND GRADUALLY COOLER TEMPERATURES AND HIGHER RELATIVE HUMIDITY WILL FOLLOW FOR THE REST OF THE WEEK. && .AFG WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FOR AKZ227. HIGH WIND WARNING FOR AKZ223-AKZ224-AKZ225-AKZ226. SMALL CRAFT ADVISORY FOR PKZ210-PKZ220-PKZ245. && $$ TF SEP 12 ______________________________________________________________________ PAFG - Reference: ['early morning polar orbiting satellite imagery shows strong'] 628 FXAK69 PAFG 281330 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 530 AM AKDT FRI SEP 28 2012 .DISCUSSION... THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS AGREE CLOSELY ON THE PROJECTIONS THROUGH SATURDAY NIGHT. INDEED...THE MODELS USED FOR THIS MORNINGS FORECASTS ARE NICELY FOLLOWING THE FORECASTS FROM EARLIER MODEL RUNS. THE LARGE TROUGH OF LOW PRESSURE ALOFT EXTENDING FROM THE HIGH ARCTIC SOUTHWARD OVER THE ALASKA MAINLAND IS FORECAST TO EXIT INTO NORTHWEST CANADA ON SUNDAY. A NEW LOW PRESSURE SYSTEM WILL MOVE INTO THE WESTERN BERING SEA NEAR CAPE NAVARIN EARLY SUNDAY. HIGH PRESSURE AHEAD OF THIS LOW WILL BUILD OVER MAINLAND ALASKA STARTING SUNDAY...AND TAKE UP RESIDENCE FOR THE REST OF THE WEEK. THE LOW PRESSURE OVER THE EASTERN BERING SEA WILL BRING BOUTS OF BRISK SOUTHEAST WINDS...PERHAPS BRIEFLY REACHING GALE STRENGTH...ALONG WITH RAIN TO THE WEST COAST. SOUTHEAST WINDS IN THAT AREA ORIGINATE FROM WARMER REGIONS AND RESULT IN THE INFLUX OF A STABLE AIR MASS. THIS IS THE OPPOSITE OF THE BRISK NORTH WINDS WHICH HAVE BEEN BLOWING OVER WESTERN ALASKA FOR THE PAST SEVERAL DAYS. COMING FROM A COLDER REGION TO THE DISTANT NORTH...THE NORTHERLY CIRCULATION BRINGS COLD AIR TO AN AREA WARMER THAN ITS ORIGIN...AND THUS FORMS AN UNSTABLE AIR MASS. THE WIND GUSTS IN AN UNSTABLE AIR MASS ARE LARGER THAN THOSE IN A STABLE AIR MASS. ANOTHER RESULT OF THE UNSTABLE AIR MASS NOW OVER THE ARCTIC AND WESTERN COASTS OF NORTHERN ALASKA IS RELATIVELY STEADY CEILING HEIGHTS DUE TO THE WELL MIXED UNSTABLE AIR MASS. THE AVIATION WEATHER IN THESE AREAS HAS BEEN STEADIER THAN IT TYPICALLY IS IN PERIODS OF ONSHORE FLOW OF STABLE AIR. A FINAL RESULT OF THE INSTABILITY OF THE ARCTIC AND WEST COAST AIR MASS IS THE ABSENCE OF FREEZING RAIN...WHICH ALMOST ALWAYS OCCURS IN STABLE AIR MASSES. IN THESE SITUATIONS...MOIST AIR WITH TEMPERATURES ABOVE FREEZING FLOATS ABOVE AIR WITH TEMPERATURES WELL BELOW FREEZING DOWN TO THE SURFACE. FORTUNATELY...TODAYS WEATHER PATTERN DIFFERS COMPLETELY WITH THAT OF A FREEZING RAIN EVENT. EARLY MORNING POLAR ORBITING SATELLITE IMAGERY SHOWS STRONG CIRCULATION OVER THE MACKENZIE DELTA OF CANADA. A TROUGH OF LOW PRESSURE AT THE SURFACE EXTENDS WESTWARD FROM THE LOW JUST OFFSHORE THE ARCTIC COAST AT FLAXMAN ISLAND. BRISK WEST WINDS HAVE BEEN BLOWING OVER THIS SECTION OF THE COAST SINCE MID DAY THURSDAY. THIS TROUGH IS A COMMON FEATURE OF CIRCULATION OVER THE EASTERN ARCTIC COAST OF ALASKA. THE NUMERICAL FORECAST MODELS ARE CONSISTENTLY PROJECTING THIS FEATURE TO DISSIPATE AT MID DAY TODAY. THE BRISK WEST WINDS OF THIS MORNING WILL QUICKLY WEAKEN AND BECOME NORTHEAST AS THIS OCCURS. THE MEDIUM RANGE FORECAST MODELS AGREE WELL IN THE TREND THROUGH THE END OF NEXT WEEK...HIGH PRESSURE ALOFT WILL BUILD AND HOLD OVER THE EASTERN AND CENTRAL MAINLAND...WHILE PERSISTENT LOW PRESSURE OVER THE BERING SEA WILL CONTINUE TO BRING UNSETTLED WEATHER TO THE WEST COAST. BEYOND THE END OF NEXT WEEK...THE NUMERICAL MODELS DIVERGE...AND THE OUTLOOK IS TYPICALLY UNCERTAIN. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .HYDROLOGY... NORTHERN ALASKA RIVERS ARE WELL WITHIN THEIR BANKS. STAGES ON MOST NORTHERN ALASKA RIVERS ARE EITHER LEVEL OR SLOWLY FALLING. THERE IS A MINOR RISE IN PROGRESS ON THE YUKON RIVER FROM THE DALTON HIGHWAY DOWN TO GALENA. LITTLE PRECIPITATION IS EXPECTED IN NORTHERN ALASKA DURING THE NEXT TWO DAYS. THE INCOMING NORTHWEST BERING SEA LOW IS EXPECTED TO BRING RAIN TO MUCH OF THE WEST COAST STARTING SUNDAY...BUT THE AMOUNT OF RAIN IS NOT FORECAST TO BE LARGE ENOUGH FOR MUCH RESPONSE ON THE RIVERS. && .AFG WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY FOR PKZ200-PKZ210-PKZ215-PKZ220-PKZ225- PKZ245. && $$ TF SEP 12 ______________________________________________________________________ PAFG - Reference: ['early morning polar orbiting satellite imagery shows a generally'] 717 FXAK69 PAFG 291406 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 606 AM AKDT SAT SEP 29 2012 .DISCUSSION... THE LARGE AREA OF LOW PRESSURE ALOFT OVER THE ALASKA MAINLAND IS WEAKENING AND WILL EXIT INTO NORTHWEST CANADA THIS WEEKEND. BY MONDAY AFTERNOON...HIGH PRESSURE ALOFT WILL BUILD OVER THE EASTERN MAINLAND IN ADVANCE OF A NEW AND MODERATELY STRONG LOW PRESSURE SYSTEM. THE NEW LOW WILL ENTER THE WESTERN BERING SEA LATE THIS AFTERNOON...AND WILL BE CENTERED NEAR SAINT MATTHEW ISLAND MONDAY AFTERNOON. THIS SEQUENCE OF EVENTS IS CONSISTENT WITH THE PAST SEVERAL DAYS OF GFS COMPUTER WEATHER FORECAST MODEL RUNS. THE NORTHERLY FLOW OF COLD AND UNSTABLE AIR FROM THE ARCTIC OVER THE WESTERN HALF OF THE REALM HAS GREATLY WEAKENED...AND WILL BE REPLACED BY SOUTHERLY FLOW ON SUNDAY. THIS SOUTHERLY CIRCULATION IS FORECAST TO STRENGTHEN SUNDAY NIGHT AND TO REMAIN VIGOROUS THROUGH MONDAY NIGHT. SOUTH TO SOUTHEAST GALES ARE EXPECTED ON THE WEST COAST DURING THIS TIME. ON TUESDAY...THE GFS MODEL FORECASTS A LARGER AND STRONGER LOW PRESSURE SYSTEM TO MOVE NORTHEASTWARD OVER THE END OF THE ALEUTIANS. ALONG WITH THIS...A STRONG SHORT WAVE ALOFT WILL CROSS OVER THE BERING SEA COAST OF NORTHERN ALASKA...AND MOVE NORTH OF THE ARCTIC COAST ON WEDNESDAY. THIS SHOULD BRING EXTENSIVE RAINFALL TO THE NORTHERN AND WESTERN INTERIOR AND THE ENTIRE WEST COAST TUESDAY EVENING AND TUESDAY NIGHT. FAIRLY STRONG SOUTH TO SOUTHWEST FLOW WILL RESUME OVER THE BERING SEA AND CHUKCHI SEA COASTS ON WEDNESDAY...AND CONTINUE FOR THE REST OF THE WEEK. AT SEA...THERE WILL BE SOUTHEASTERLY GALES OVER ALL OF THE WESTERN COAST STARTING WEDNESDAY AND CONTINUING THROUGH FRIDAY. IN SUM...IT LOOKS LIKE ANOTHER WEEK OF ROUGH AND UNSETTLED WEATHER OUT WEST. OVER THE INTERIOR...COOLING ALOFT HAS BEEN TAKING PLACE SINCE YESTERDAY. THE PATTERN IS THAT OF AN ADVANCING ARCTIC FRONT...A WEATHER SYSTEM WHICH USUALLY BRINGS EXTENSIVE SNOWFALL TO THE INTERIOR. OVERNIGHT THERE HAS BEEN SNOW IN MUCH OF THE SOUTHWESTERN INTERIOR. GIVEN THE GRADUAL EASTWARD ADVANCE OF THIS FRONT ALOFT...THIS MORNINGS FORECASTS INCLUDE UP TO 2 INCHES OF NEW SNOWFALL FOR TODAY. THIS PROCESS WILL BE DECISIVELY REVERSED MONDAY NIGHT AND TUESDAY AS TEMPERATURES RISE. THE GFS AND EUROPEAN MEDIUM RANGE MODEL FORECASTS DIVERGE ONCE THE PROJECTIONS REACH THE MIDDLE OF NEXT WEEK. THE GFS MODEL FORECASTS THE LOW IN THE WESTERN ALEUTIANS TO BE SIGNIFICANTLY STRONGER THAN THE EUROPEAN MODEL DOES. THE MAKINGS OF THIS LOW PRESSURE SYSTEM ARE THE REMAINS OF TROPICAL STORM EWINIAR...WHICH MOVED SLOWLY THROUGH THE WESTERN NORTH PACIFIC EARLIER THIS WEEK. SUCH SYSTEMS ALMOST ALWAYS STRENGTHEN SIGNIFICANTLY ONCE THEY REACH THE MID LATITUDES...ESPECIALLY THOSE WHICH MOVE UP OVER THE ALEUTIANS TO THE BERING SEA. FOR THIS REASON...THE GFS MODEL IS THE MODEL OF CHOICE FOR TODAY. EARLIER THIS WEEK...THE GFS WAS THE MODEL OF CHOICE BECAUSE IT HAD A REALISTIC FORECAST OF THE HIGH PRESSURE ALOFT WHICH IS DUE TO BUILD OVER THE EASTERN MAINLAND ON MONDAY. THIS STRENGTHENS THE CASE FOR THE GFS MODEL TO REMAIN THE PREFERRED MODEL FOR TODAYS FORECASTS. EARLY MORNING POLAR ORBITING SATELLITE IMAGERY SHOWS A GENERALLY DISORGANIZED ASSORTMENT OF CLOUDS OVER NEARLY ALL OF NORTHERN ALASKA. THERE IS SOME CLEAR WEATHER OVER THE NOATAK AND WULIK RIVER VALLEYS...THE CHUKCHI SEA EAST OF POINT HOPE AND BERING STRAIT...AND THE DIOMEDES. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .HYDROLOGY... NORTHERN ALASKA RIVERS ARE ALL WELL WITHIN THEIR BANKS AND MOST ARE RECEDING. SOME SMALL RISES HAVE BEEN OBSERVED ON THE YUKON RIVER FROM THE CANADA BORDER TO GALENA...BUT THESE HAVE COME ON STAGES FAR BELOW FLOOD LEVELS. FREEZEUP ON ARCTIC STREAMS WILL BEGIN IN THE NEXT TWO WEEKS. && .AFG WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY FOR PKZ210. && $$ TF SEP 12 ______________________________________________________________________ PAFG - Reference: ['polar orbiting satellite imagery has shown extensive convective'] 111 FXAK69 PAFG 151301 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 501 AM AKDT MON OCT 15 2012 .DISCUSSION... THE GFS AND NAM COMPUTER WEATHER FORECAST MODELS ARE IN GOOD AGREEMENT THROUGH 4 AM WEDNESDAY. A LARGE AND LONG-LIVED LOW PRESSURE SYSTEM NOW ABOUT 600 MILES NORTHWEST OF BARROW IS GRADUALLY WEAKENING...AND DRIFTING SLOWLY TO THE NORTHWEST. THE WEATHER AT SEA IN THE CHUKCHI AND ALONG THE ALASKAN CHUKCHI SEA COAST IS THE MOST IMPORTANT ASPECT OF THIS MORNINGS FORECASTS. COLD AIR HAS BEEN STREAMING DOWN FROM THE FAR NORTHWESTERN CHUKCHI SEA THROUGH BERING STRAIT. THE EDGE OF THE ARCTIC ICE PACK IS NOW ABOUT 400 MILES NORTHWEST OF BARROW...AND ADVANCING SOUTHWARD 10 TO 15 MILES A DAY. THE ABNORMALLY LONG FETCH OVER THE CHUKCHI SEA DOWN TO THE ALASKA ARCTIC COAST WEST OF CAPE HALKETT IS THE MAIN FACTOR IN THE BUILDUP OF ROUGH SEAS. THE INCOMING SWELLS AT BARROW HAVE BEEN FROM 4 TO 6 FEET HIGH. DUE TO ABNORMALLY FREQUENT WEST WINDS IN THE ALASKAN ARCTIC THIS SUMMER AND FALL...THE WIDE BEACH AND SHALLOW WATER OUT FROM SHORE HAVE BEEN MUCH REDUCED. AS A RESULT...THE INCOMING SWELLS ON THE ALASKAN NORTHERN ARCTIC COAST ARE NOT BREAKING SEVERAL HUNDRED YARDS OFFSHORE AS THEY USUALLY DO. INSTEAD...THE INBOUND SWELLS ARE NOT BREAKING UNTIL REACHING THE SHORELINE. THE RUN UP OF THE BREAKING SURF IS CONSIDERABLY MORE NOW THAN IT WOULD BE UNDER NORMAL SHORELINE CONDITIONS. POLAR ORBITING SATELLITE IMAGERY HAS SHOWN EXTENSIVE CONVECTIVE CLOUDS OVER THE CHUKCHI SEA. THIS...AND THE EARLY MORNING WEATHER BALLOON DATA FROM BARROW...KOTZEBUE...AND NOME...INDICATE AN UNSTABLE AIR MASS. THIS FEATURE GIVES A LARGER TRANSFER OF ENERGY FROM THE WIND TO THE SEA. THIS HAS BEEN THE CASE FOR SEVERAL DAYS NOW. A LARGE LOW PRESSURE SYSTEM ALOFT NOW EXTENDS FROM THE EASTERN CHUKCHI SEA DOWN TO BRISTOL BAY...AND HIGH PRESSURE ALOFT IS OVER THE YUKON TERRITORY. THERE IS ALSO A LARGE AREA OF HIGH PRESSURE ALOFT OVER THE RUSSIAN FAR EAST. BY WEDNESDAY...MOST OF THE LOW PRESSURE WILL TRANSFER TO THE GULF OF ALASKA...AND THE REMAINDER WILL WEAKEN OVER THE NORTHEASTERN CHUKCHI SEA. BY THURSDAY NIGHT...THE HIGH PRESSURE NOW OVER THE RUSSIAN FAR EAST WILL BUILD OVER THE BERING SEA. NORTHEAST FLOW WILL PREVAIL OVER NEARLY ALL OF NORTHERN ALASKA. THIS AREA OF HIGH PRESSURE HAS BEEN FORECAST TO BE QUITE STRONG BY THE FORECAST MODELS FOR THE PAST SEVERAL DAYS. THE GFS MODEL FORECASTS BRISK NORTH TO NORTHWEST FLOW ALOFT TO PREVAIL OVER THE REALM THROUGH EARLY NEXT WEEK. STRONG HIGH PRESSURE ALOFT IS FORECAST TO REMAIN OVER THE SOUTHERN MAINLAND OF ALASKA THROUGH THE MIDDLE OF NEXT WEEK. ALTHOUGH THE STRENGTH OF THIS HIGH PRESSURE IN THE FORECAST MODELS IS UNUSUAL...IT IS POSSIBLE. SEASONABLE TO ABOVE NORMAL TEMPERATURES WILL PREVAIL OVER NORTHERN ALASKA FOR THE NEXT 7 TO 10 DAYS. THE OCCLUDED FRONT NOW OVER THE SOUTHERN MAINLAND IS BRINGING SNOWFALL TO THE SOUTHEASTERN INTERIOR. THE AREA OF SNOWFALL IS FORECAST TO EXTEND WESTWARD THROUGH TONIGHT. SEVERAL INCHES OF NEW SNOW IS EXPECTED OVER THE EASTERN INTERIOR DURING THE NEXT 48 HOURS. NORTHERN ALASKA RIVERS ARE WELL WITHIN THEIR BANKS AND MOST ARE SLOWLY DROPPING. THERE IS ONE EXCEPTION...THE FORTYMILE RIVER AT THE TAYLOR HIGHWAY BEGAN RISING SATURDAY AFTERNOON...AS A RESULT OF SIGNIFICANT RAINFALL IN THE YUKON-TANANA UPLANDS FRIDAY AND SATURDAY. THE RIVER CAME UP 5 FEET...AND HAS JUST CRESTED. IT IS SLOWLY FALLING NOW. COASTAL HAZARD POTENTIAL DAYS 3 AND 4 /WEDNESDAY AND THURSDAY/...NONE && .AFG WATCHES/WARNINGS/ADVISORIES... HIGH SURF ADVISORY FOR AKZ202-AKZ207-AKZ213. SMALL CRAFT ADVISORY FOR PKZ200-PKZ210-PKZ215-PKZ220-PKZ225. && $$ TF/CC OCT 12 ______________________________________________________________________ PAFG - Reference: ['early morning polar satellite imagery over the mainland of alaska'] 305 FXAK69 PAFG 171414 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 614 AM AKDT WED OCT 17 2012 .DISCUSSION... THE LARGE AREA OF LOW PRESSURE ALOFT EXTENDING SOUTHWARD OVER THE ALASKA MAINLAND FROM THE EASTERN CHUKCHI SEA IS FORECAST TO CONTINUE SPLITTING INTO A WEAK ARCTIC PORTION AND A MODERATELY STRONG GULF OF ALASKA PORTION. THE GFS AND NAM COMPUTER WEATHER FORECAST MODELS PROJECT HIGH PRESSURE ALOFT NOW OVER THE WESTERN BERING SEA TO BUILD OVER THE CENTRAL AND EASTERN BERING SEA THURSDAY...AND THEN TO REMAIN OVER THAT AREA THROUGH THE WEEKEND AND BEYOND. THE GFS MODEL FORECASTS A LARGE AREA OF HIGH PRESSURE ALOFT TO REMAIN OVER WESTERN ALASKA THROUGH NEXT WEEK. CIRCULATION ALOFT OVER ALASKA IS FORECAST TO SIGNIFICANTLY WEAKEN. THE GFS MODEL FORECAST IS NOT CONSISTENT WITH EARLIER RUNS...WHICH FORECAST THE BERING SEA HIGH PRESSURE SYSTEM TO WEAKEN IN THE SECOND HALF OF THIS WEEK...AND FOR LOW PRESSURE FROM THE NORTHWEST PACIFIC TO STRENGTHEN AS IT MOVED NORTHWARD OVER SIBERIA. THE MOST RECENT NORTH PACIFIC SURFACE ANALYSES SUGGEST THAT THE LATEST GFS MODEL RUN IS MORE REASONABLE THAN EARLIER RUNS. THIS IS BECAUSE THE LOW PRESSURE SYSTEM NOW HEADED TOWARD SIBERIA CLEARLY LACKS THE ENERGY REQUIRED TO BE IN LINE WITH EARLIER MODEL RUNS. THERE ARE SEVERAL RELEVANT SHORTER TERM WEATHER FEATURES. FIRST...THE THREE INBOUND SHORT WAVES ALOFT...WHICH WERE MOVING SLOWLY NORTHWESTWARD OVER THE ALASKA MAINLAND 24 HOURS AGO...ARE CONTINUING TO DRIFT WESTWARD. THE FIRST IS MUCH WEAKENED...AND NOW EXTENDS FROM WAINWRIGHT DOWN TO ILIAMNA. THE SECOND EXTENDS FROM CAPE HALKETT / ON THE NORTHERN ARCTIC COAST / DOWN TO THE WESTERN ALASKA RANGE. THE THIRD IS NOW OVER THE SOUTHEASTERN INTERIOR. ALL THREE OF THESE TROUGHS OF LOW PRESSURE ALOFT ARE CAUSING LIGHT SNOW OVER INTERIOR ALASKA. SO FAR...SNOWFALL OVER THE PAST 2 DAYS HAS BEEN FROM 1 TO 3 INCHES. ANOTHER SUCH TROUGH ALOFT COULD FORM IN THE PATHS OF ITS PREDECESSORS LATER TODAY. THIS REMAINS TO MATERIALIZE...BUT IS A POSSIBILITY. THE PARENT LOW ALOFT...FROM WHICH THESE TROUGHS ALOFT HAVE EMERGED...REMAINS JUST SOUTH OF PRINCE WILLIAM SOUND. THE FLOW OF UNSTABLE ARCTIC AIR FROM THE CHUKCHI SEA SOUTHWARD OVER ALASKAS CHUKCHI SEA AND WEST COASTS CONTINUES...AS DO THE SNOW SHOWERS WHICH HAVE ACCOMPANIED IT FOR DAYS. A SMALL LOW PRESSURE SYSTEM THAT FORMED JUST NORTH OF PRUDHOE BAY HAS GAINED SOME STRENGTH IN THE PAST 12 HOURS. THERE IS A SMALL AREA OF STRONG NORTH WINDS ON THE WEST SECTOR OF THIS LOW. BARROW HAS HAD NORTH WINDS 20 TO 30 MPH WITH BLOWING SNOW SINCE LATE YESTERDAY EVENING. THIS AREA OF STRONG NORTH WINDS IS LESS THAN 100 MILES WIDE...AND IS EXPECTED TO REMAIN THERE TODAY...AND THEN TO WEAKEN TONIGHT AS THE LOW PRESSURE CENTER NOW ABOUT 100 MILES NORTHWEST OF PRUDHOE BAY WEAKENS. THE SHIFT IN THE WIND FROM NORTHWEST TO NORTH AT BARROW HAS SIGNIFICANTLY CHANGED NEAR SHORE SEA CONDITIONS. SWELLS INBOUND FROM THE NORTH ARE REFRACTED AROUND POINT BARROW...AND LOSE STRENGTH IN THE PROCESS. WHEN THE WIND AND SWELLS WERE COMING IN FROM THE NORTHWEST YESTERDAY AND THE DAY BEFORE...THE FULL FORCE OF THE SWELLS WAS DELIVERED TO THE BEACH AT BARROW. EARLY MORNING POLAR SATELLITE IMAGERY OVER THE MAINLAND OF ALASKA SHOWS A COMPLEX ARRANGEMENT OF CLOUDS ALIGNED WITH THE TROUGHS ALOFT. THE ENTIRE INTERIOR AND ARCTIC ARE OVERCAST. SKIES ARE CLEAR OVER NORTON SOUND AND OFFSHORE KOTZEBUE SOUND...AND THERE AREA SCATTERED SNOW SHOWERS OUT AT SEA BEYOND THE WESTERN ALASKA COAST. COASTAL HAZARD POTENTIAL DAYS 3 AND 4.../FRIDAY AND SATURDAY/...NONE. && .AFG WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FOR AKZ206-AKZ218. SMALL CRAFT ADVISORY FOR PKZ200-PKZ215-PKZ230-PKZ235-PKZ240. && $$ TF OCT 12 ______________________________________________________________________ PAFG - Reference: ['todays early morning polar orbiting satellite imagery shows'] 640 FXAK69 PAFG 201357 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 557 AM AKDT SAT OCT 20 2012 .DISCUSSION... THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS ARE IN NEARLY EXACT AGREEMENT ON THE FORECAST INTO EARLY NEXT WEEK. THE HIGH AMPLITUDE RIDGE OF HIGH PRESSURE ALOFT NOW OVER THE EASTERN HALF OF THE BERING SEA IS FORECAST TO MOVE OVER THE WESTERN INTERIOR TONIGHT AND TO THE YUKON TERRITORY SUNDAY NIGHT. THE GFS MODEL RUNS FOR THE PAST SEVERAL DAYS HAVE FORECAST THIS SEQUENCE OF EVENTS VERY WELL. THE INBOUND WEATHER SYSTEM OF INTEREST IS A LOW PRESSURE CENTER NOW ABOUT 200 MILES SOUTHWEST OF ATTU / THE WEST END OF THE ALEUTIAN ISLAND CHAIN. / FROM THE LOOKS OF THE GEOSTATIONARY SATELLITE IMAGERY...THE GFS MODEL HAS UNDER FORECAST THE STRENGTH OF THIS SYSTEM. THE GFS MODEL FORECASTS THE LOW TO MOVE NEARLY STRAIGHT NORTHWARD...TO REACH THE GULF OF ANADYR TONIGHT AND WRANGEL ISLAND SUNDAY NIGHT. A BELT OF SOUTH TO SOUTHEAST GALE FORCE WINDS EAST OF THE LOW IS EXPECTED TO REACH THE WEST COAST OF NORTHERN ALASKA THIS EVENING AND TO REACH ITS PEAK STRENGTH LATE TONIGHT. IF IN FACT THIS INCOMING LOW STRENGTHENS MORE THAN THE MODEL HAS FORECAST IT TO...IT WILL MOVE MORE SLOWLY THAN THE MODEL PREDICTS. THIS APPEARS TO BE THE LIKELY OUTCOME. FOR THIS REASON...THIS MORNINGS FORECASTS FOR THE WEST COAST INCLUDE BRISK TO GALE FORCE WINDS FOR A LONGER SPAN OF TIME THAN THE GFS MODEL DOES. THE LARGE AREA OF THICK CLOUDS AHEAD OF THE INBOUND LOW HAS MOVED RAPIDLY NORTHWARD IN THE PAST 10 HOURS...FROM THE WESTERN ALEUTIANS TO THE CENTRAL BERING SEA. THE LOW STRATUS CLOUDS WHICH COVER THE ENTIRE WEST COASTAL REGION OF THE REALM WILL BE ABSORBED INTO THESE ADVANCING FRONTAL CLOUDS AS TODAY WEARS ON. EXTENSIVE PRECIPITATION...FIRST SNOW...AND THEN RAIN...IS EXPECTED OVER THE COAST SOUTH OF BERING STRAIT. THERE HAS BEEN WIDESPREAD FOG OVER THE YUKON DELTA...NORTON SOUND COAST AND BERING STRAIT. THIS WILL THIN OUT SOME AS THE FRONTAL CLOUDS ADVANCE OVERHEAD TODAY. STARTING AROUND NOON YESTERDAY...THE SNOW FALLING OVER THE BERING STRAIT COAST BECAME MIXED WITH FREEZING DRIZZLE. THIS CONTINUED FOR MOST OF FRIDAY NIGHT AT TIN CITY...WALES AND TELLER. THE TEMPERATURE ROSE ABOVE FREEZING AT WALES AT MID DAY FRIDAY...AND TIN CITY ABOUT 4 AM THIS MORNING. THE PRECIPITATION HAS ENDED FOR NOW AT TELLER AND WALES. WHEN IT RESUMES...IT WILL COME MOSTLY AS RAIN...AND THE TEMPERATURE WILL BE A COUPLE OF DEGREES ABOVE FREEZING. TODAYS EARLY MORNING POLAR ORBITING SATELLITE IMAGERY SHOWS OVERCAST STRATUS NEARLY EVERYWHERE WEST OF BARROW...INDIAN MOUNTAIN AND MCGRATH. ABOUT HALF OF THE UPPER KOYUK VALLEY...PART OF THE SOUTHEASTERN BROOKS RANGE...AND MOST OF THE YUKON FLATS AND FORTYMILE COUNTRY IS ALSO UNDER OVERCAST DECKS OF STRATOCUMULUS. THE CLOUDS OVER THE INTERIOR HAVE BEEN SURPRISINGLY RESILIENT. CLEARING IS EXPECTED BY NOON AS HIGH PRESSURE OVER THE WEST COAST BUILDS INTO THE INTERIOR. THE CLEARING SKIES OVER THE REST OF THE INTERIOR...COMBINED WITH TEMPERATURES BELOW FREEZING AND LINGERING OPEN WATER ON AREA RIVERS...HAVE PRODUCED NIGHTTIME AND EARLY MORNING LOW CLOUDS AND FOG ALONG THE RIVERS. THIS MAY WELL RECUR ALONG EASTERN INTERIOR RIVERS TONIGHT. TEMPERATURES OVER THE WESTERN PART OF THE REALM ARE EXPECTED TO RISE ABOVE NORMAL. SOME OF THE TEMPERATURE RISE WILL BE SIGNIFICANT. FOR INSTANCE...BARROWS TEMPERATURE IS FORECAST TO RISE FROM 3 ABOVE AT 5 AM THIS MORNING TO 24 ABOVE THIS AFTERNOON. THE COLDEST REGION IN NORTHERN ALASKA THIS MORNING IS THE CENTRAL BROOKS RANGE AND THE CENTRAL ARCTIC SLOPE...TEMPERATURES THERE CURRENTLY RANGE FROM ZERO TO 10 BELOW. COASTAL HAZARD POTENTIAL DAYS 3 AND 4 /MONDAY AND TUESDAY/...NONE && .AFG WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY FOR PKZ210-PKZ220-PKZ225-PKZ230-PKZ235. GALE WARNING FOR PKZ210. && $$ TF OCT 12 ______________________________________________________________________ PAFG - Reference: ['this mornings polar orbiting satellite imagery shows a vast area'] 401 FXAK69 PAFG 211252 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 452 AM AKDT SUN OCT 21 2012 .DISCUSSION... YESTERDAYS GFS COMPUTER WEATHER FORECAST MODEL RUNS TURNED OUT TO BE BETTER THAN FIRST THOUGHT. THE WEST BERING SEA LOW ARRIVED IN THE GULF OF ANADYR RIGHT ON SCHEDULE...AT 4 AM AKDT THIS MORNING. AND THE CURRENT GFS MODEL RUN HAS THE LOW OVER WRANGEL ISLAND 24 HOURS FROM NOW. THE NAM MODEL AGREES ON THIS. THE TWO MODEL RUNS DIVERGE ON THE DEVELOPMENT AND MOVEMENT OF THE TROUGH OF LOW PRESSURE ALOFT BEHIND THE WEST BERING SEA LOW. THE NAM MODEL MAINTAINS THE SHARP AXIS OF THIS FEATURE AS IT IS PREDICTED TO MOVE OVER THE INTERIOR TONIGHT AND MONDAY...AND REACHING THE YUKON BORDER MONDAY NIGHT. THE GFS MODEL PREDICTS THE TROUGH TO MOVE UP OVER THE BEAUFORT SEA ON MONDAY NIGHT. BOTH MODELS FORECAST ANOTHER HIGH AMPLITUDE RIDGE OF HIGH PRESSURE ALOFT TO BUILD OVER THE EASTERN BERING SEA TONIGHT...AND THEN OVER THE WEST COAST MONDAY NIGHT. FOR MONDAY NIGHT..,THE GFS MODEL FORECASTS NORTHERLY FLOW ALOFT OVER THE ENTIRE ALASKA MAINLAND WHICH IS STRONGER AND MORE EXTENSIVE THAN THE NAM FORECAST FOR MONDAY NIGHT. THE GFS FORECAST OF THIS SYSTEM APPEARS TO PREDICT CIRCULATION ALOFT THAT IS TOO STRONG. THE NAM MODEL LOOKS MORE REASONABLE ON THIS. BOTH MODELS PROJECT A NEW WEST PACIFIC LOW TO REACH THE WEST END OF THE ALEUTIANS MONDAY NIGHT. FOLLOWING THIS...THE GFS FORECASTS THIS LOW TO DROP SOUTHEASTWARD...DOWN TO THE MID LATITUDE WESTERLIES...AND TO MOVE FARAWAY FROM THE REALM. THE BELT OF SOUTHEASTERLY GALES AHEAD OF THIS LOW IS FORECAST TO REMAIN WEST OF THE SAINT LAWRENCE ISLAND WATERS WHEN IT MAKES ITS CLOSEST APPROACH ON MONDAY NIGHT. TURNING BACK TO THE SHORTER RANGE...SOUTHERLY GALES EXTEND FROM DALL POINT UP TO POINT HOPE. THESE HAVE DRIVEN THE ARCTIC AIR WHICH HAD BLANKETED MUCH OF THE AREA NORTHWARD. TEMPERATURES ON THE WESTERN COAST RANGE FROM THE MID 20S TO MID 30S. BARROWS TEMPERATURE REACHED 30 DEGREES YESTERDAY EVENING. TEMPERATURES IN THE WEST ARE EXPECTED TO DROP ABOUT 5 DEGREES OVER THE NEXT 24 HOURS. A MIXTURE OF RAIN AND SNOW IS EXPECTED OVER WESTERN NORTON SOUND...SAINT LAWRENCE ISLAND...AND FROM BERING STRAIT UP TO POINT HOPE THROUGH MONDAY MORNING. OVER THE ARCTIC...CONSISTENTLY OFFSHORE WINDS FINALLY CARRIED THE LOW CLOUDS AND SPOTTY FOG THAT HAD LINGERED OVER IT...WELL OFFSHORE. HIGHER CLOUDS AHEAD OF THE WESTERN BERING SEA LOW ARE NOW ADVANCING OVER THE WEST HALF OF THE ARCTIC. HIGH SURF ADVISORIES FOR THE BERING STRAIT COAST AND FOR THE CHUKCHI SEA COAST FROM KIVALINA NORTH TO POINT HOPE WERE CLOSED OUT EARLIER THIS MORNING. THE THREAT OF HIGH SURF ENDED AS IT BECAME CLEAR THAT BOTH THE FETCH LENGTH AND THE DURATION OF SOUTHERLY GALES WOULD BE TOO SHORT.THE WESTERN BERING SEA LOW MOVED NORTHWARD AT A SPEED OF 60 KNOTS DURING ALL OF SATURDAY. THE STRONGEST WINDS IN NORTHERN ALASKA OVERNIGHT WERE AT WALES...ON THE WESTERN END OF THE SEWARD PENINSULA...WHERE SOUTH WINDS HAVE GUSTED TO 58 MPH. STRONG SOUTHERLY WINDS ARE EXPECTED TO CONTINUE TODAY OVER THE NORTHWEST ALASKA COAST. THIS MORNINGS POLAR ORBITING SATELLITE IMAGERY SHOWS A VAST AREA OF STRATOCUMULUS OVERCAST COVERING NEARLY ALL OF THE WESTERN INTERIOR AND WESTERN COASTAL ZONES...THE YUKON FLATS...AND THE DELTANA AND TANANA FLATS. THE HORIZONTAL EXTENT OF THESE CLOUDS INCREASED A LITTLE...AND THE TOPS OF THE CLOUDS BECAME LOWER...IN THE PAST 24 HOURS. SOME OF THESE LOW CLOUDS WILL PROBABLY SURVIVE THE DAY TODAY. THE MODEL OUTPUT STATISTICS HAVE INDICATED THAT THE CLOUDS WOULD CLEAR...AND HAVE NOT SUCCEEDED FOR TWO DAYS. THEREFORE...THE FORECASTS OF CLEARING SKIES OVER THE INTERIOR LATER TODAY...ARE NOT HIGH CONFIDENCE PROJECTIONS. THE COLDEST TEMPERATURES IN NORTHERN ALASKA THIS MORNING RANGE FROM ZERO TO 20 BELOW IN THE SOUTHEASTERN BROOKS RANGE. TEMPERATURES ON THE NORTH SLOPES OF THE BROOKS RANGE HAVE RISEN TO THE 20S. THE STRONG INFLUX OF WARM SOUTH WINDS INTO THE CHUKCHI SEA HAS HELD BACK THE GROWTH OF THE ICE PACK IN THAT AREA. IT REMAINS ABOUT 200 MILES NORTHWEST OF THE COAST FROM POINT HOPE TO BARROW. IN THE EAST...SOME NEW SHORE ICE HAS BEEN FORMING FROM BARROW EAST TO THE CANADA BORDER. SURFACE AIR TEMPERATURES ABOVE THE PACK ICE HAVE REMAINED RELATIVELY MILD...IN THE MID 20S DOWN TO THE TEENS FARTHER NORTH. SEA ICE DOES GROW IN THIS SORT OF ENVIRONMENT...BUT NOT VERY FAST. COASTAL HAZARD POTENTIAL DAYS 3 AND 4 / TUESDAY AND WEDNESDAY/ ...NONE && .AFG WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FOR AKZ207-AKZ213. SMALL CRAFT ADVISORY FOR PKZ200-PKZ215-PKZ235. GALE WARNING FOR PKZ210-PKZ220-PKZ225-PKZ230. && $$ TF OCT 12 ______________________________________________________________________ PAFG - Reference: ['conclusively...clearing this morning. early morning polar orbiting'] 615 FXAK69 PAFG 221303 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 503 AM AKDT MON OCT 22 2012 .DISCUSSION... THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS PROJECT PRETTY MUCH THE SAME OUTCOME FOR THE THREE IMPORTANT WESTERN BERING SEA LOWS ON THIS MORNINGS CHARTS. FIRST...THE LOW THAT BROUGHT HIGH WINDS TO THE NORTHWEST COAST YESTERDAY IS NOW WEAKENING JUST SOUTH OF WRANGEL ISLAND. /THE PEAK REPORTED WINDS YESTERDAY WERE 64 MPH AT WALES...AT BERING STRAIT...AND 61 MPH AT THE RED DOG MINE DOCK...ABOUT 110 MILES NORTHWEST OF KOTZEBUE./ THE LOW IS FORECAST TO BE A 1018 MILLIBAR CENTER ABOUT 700 MILES NORTH OF BARROW AT THIS TIME TUESDAY MORNING. THE SECOND LOW PRESSURE SYSTEM IS NOW A 986 MILLIBAR CENTER JUST OFFSHORE THE NORTHEASTERN COAST OF THE KAMCHATKA PENINSULA. DESPITE ITS HEALTHY APPEARANCE ON THE 4 PM SUNDAY SURFACE ANALYSIS AND ON GEOSTATIONARY SATELLITE IMAGERY THIS MORNING...LITTLE IS FORECAST TO COME OF THIS SYSTEM AS IT MOVES NORTHWESTWARD INTO THE NORTHERN SEA OF OKHOTSK AND RAPIDLY WEAKENS THIS AFTERNOON. THE THIRD SYSTEM RAPIDLY CAME INTO VIEW ON GEOSTATIONARY SATELLITE IMAGERY YESTERDAY EVENING AS IT MOVED NORTHWARD AND QUICKLY GAINED DEFINITION AND VIGOR. AS IS THE CASE WITH THE SECOND LOW /ITS PREDECESSOR/...THIS SYSTEM IS RUNNING INTO STRONG HIGH PRESSURE ALOFT OVER THE EASTERN AND CENTRAL BERING SEA. AFTER LINGERING JUST SOUTH OF THE WESTERN ALEUTIANS TODAY AND TONIGHT...THIS THIRD LOW IS PREDICTED TO MOVE SOUTHEASTWARD...FAR DOWN INTO THE MID LATITUDE WESTERLIES. THIS IS CONSISTENT WITH YESTERDAYS MODEL RUNS. THE BELT OF SOUTHEAST GALES AHEAD OF THE THIRD LOW IS FORECAST TO REMAIN SOUTH OF THE SAINT LAWRENCE ISLAND WATERS AND THE YUKON DELTA TONIGHT AND TUESDAY. THE WINDS WILL WEAKEN TUESDAY NIGHT. THE WEATHER FRONT AHEAD OF THE FIRST LOW HAS BEEN RAPIDLY WEAKENING OVER THE WESTERN MAINLAND OF ALASKA. THERE ARE SCATTERED SNOW SHOWERS OVER THE WEST COAST...EXPECTED TO BE MIXED WITH RAIN TODAY. SOUTHEAST GALES ARE STILL BLOWING OVER THE CHUKCHI SEA COAST FROM KIVALINA TO CAPE LISBURNE...BUT THESE ARE FORECAST TO WEAKEN AT MID DAY TODAY. AS YESTERDAYS MODEL RUNS WERE SHOWING...TODAYS MODEL RUNS PREDICT THE HIGH AMPLITUDE HIGH PRESSURE SYSTEM ALOFT NOW OVER THE CENTRAL AND EASTERN BERING SEA TO BUILD OVER THE ENTIRE BERING SEA AND WESTERN ALASKA BY LATE TUESDAY. THE GFS FORECAST STRENGTH OF THIS LOW IS 5760 METERS AT THE 500 MILLIBAR LEVEL. THIS IS AN UNUSUALLY HIGH STRENGTH FOR LATE OCTOBER...BUT IT LOOKS AS THOUGH IT WILL COME CLOSE TO VERIFYING. THE OUTCOME OF THE INFLUX OF DRY AIR FROM THE NORTHWEST OVER ALL THE REALM BY TUESDAY WILL BE CLEAR WEATHER NEARLY EVERYWHERE IN NORTHERN ALASKA EXCEPT THE ARCTIC SLOPE AND THE ARCTIC COAST. THE CHANCES OF SNOWFALL IN THE ARCTIC AFTER TODAY ARE SLIGHT FOR MOST OR ALL OF THIS WEEK. THE REMARKABLY PERSISTENT STRATOCUMULUS AND STRATUS CLOUDS THAT BLANKETED MOST OF THE INTERIOR YESTERDAY IS FINALLY...AND CONCLUSIVELY...CLEARING THIS MORNING. EARLY MORNING POLAR ORBITING SATELLITE IMAGERY SHOWS LINGERING OVER THE YUKON FLATS...THE MIDDLE YUKON VALLEY SOUTH OF GALENA...AND NEARLY ALL OF THE UPPER KUSKOKWIM VALLEY. CLEARING OF THESE CLOUDS WILL TAKE MOST OR ALL OF THIS MORNING. AND...AS WAS THE CASE YESTERDAY...THE FOG AT NORTHWAY IS NOT EXPECTED TO CLEAR UNTIL LATE THIS MORNING. AS CAN BE EXPECTED WITH THE RELATIVELY WARM TEMPERATURES ALOFT WHICH COME WITH STRONG HIGH PRESSURE...TEMPERATURES IN NORTHERN ALASKA HAVE BEEN NEAR OR ABOVE NORMALS FOR THIS TIME OF YEAR. THERE WILL BE COLDER TEMPERATURES AS SKIES CONTINUE TO CLEAR. ALSO...THE NORTH FLOW OVER THE EASTERN MAINLAND STARTING TUESDAY NIGHT...AND FURTHER STRENGTHENING LATE THIS WEEK...WILL BRING COLDER WEATHER TO THE EASTERN INTERIOR AND THE EASTERN ARCTIC. OVERNIGHT LOW TEMPERATURES IN CLEAR VALLEYS IN THE EASTERN INTERIOR HAVE MOSTLY RANGED FROM ZERO TO 20 BELOW. IN THE MEDIUM RANGE...THE GFS MODEL FORECASTS A SERIES OF LOW PRESSURE SYSTEMS TO EMERGE IN THE WESTERN CHUKCHI SEA STARTING WEDNESDAY...AND TO MOVE SOUTHEASTWARD OVER THE BEAUFORT SEA TO THE MACKENZIE RIVER DELTA. THIS IS STILL A DISTANCE AWAY IN TIME...BUT AT LEAST THROUGH MID WEEK THIS WEEK...THE GFS FORECAST APPEARS TO BE CREDIBLE. COASTAL HAZARD POTENTIAL DAYS 3 AND 4 /WEDNESDAY AND THURSDAY/...NONE && .AFG WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY FOR PKZ215-PKZ220-PKZ230. GALE WARNING FOR PKZ225. && $$ TF OCT 12 ______________________________________________________________________ PAFG - Reference: ['early morning polar orbiting satellite imagery shows overcast low'] 466 FXAK69 PAFG 231400 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 600 AM AKDT TUE OCT 23 2012 .DISCUSSION... THE GFS AND NAM COMPUTER WEATHER FORECAST MODELS HAVE CLOSELY SIMILAR PROJECTIONS THROUGH EARLY THURSDAY. A DISTURBANCE IN THE WESTERLY WINDS ALOFT OVER THE EASTERN ALASKA ARCTIC WILL EXIT INTO THE NORTHERN YUKON TERRITORY THIS AFTERNOON. STRONG HIGH PRESSURE ALOFT HAS BUILT OVER THE BERING SEA AND IS EXPECTED TO HOLD FOR THE REST OF THIS WEEK. A PROLONGED INFLUX FROM THE NORTH OF DRY AND COOL AIR ALOFT IS GOING TO BE THE RESULT OVER THE EASTERN AND SOUTHERN INTERIOR. GIVEN THE ABSENCE OF MUCH MOISTURE IN THE ARCTIC SOURCE REGION OF THIS FLOW...CLEAR SKIES ARE EXPECTED JUST ABOUT EVERYWHERE. THE EXCEPTION CONTINUES TO BE THE FLATS ALONG INTERIOR RIVERS. ONCE AGAIN...THE YUKON FLATS /THE AREA WHERE FORT YUKON IS LOCATED/ IS BLANKETED WITH LOW CLOUDS AND SOME AREAS OF FOG. THIS HAS BEEN GOING ON FOR DAYS NOW...AND COULD WELL CONTINUE FOR SEVERAL MORE DAYS...EVEN THOUGH THE AREAL EXTENT OF THESE REMARKABLY RESILIENT CLOUDS HAS BEEN DECREASING. THE STORMY WEATHER IN NORTHWEST ALASKA HAS LONG ENDED NOW. THE TWO WEST PACIFIC LOW PRESSURE SYSTEMS THAT WERE ON THE MAP YESTERDAY MORNING HAVE DONE WHAT WAS FORECASTED BY THE GFS MODEL. THE SECOND LOW BACKED INTO THE SEA OF OKHOTSK AND VANISHED LAST NIGHT. THE THIRD LOW IS MILLING AROUND SOUTH OF THE WESTERN ALEUTIANS AND IS DUE TO PULL AWAY...SOUTHEASTWARD INTO THE MID LATITUDES OF THE NORTH PACIFIC. THE BELT OF GALE FORCE WINDS AHEAD OF THIS LOW HAS EXPANDED TO COVER MOST OF THE SOUTHERN AND CENTRAL BERING SEA...BUT AS EXPECTED...IS NOT GOING TO REACH THE SAINT LAWRENCE ISLAND WATERS. THE UPSHOT OF ALL OF THIS IS THAT NO SIGNIFICANT WEATHER SYSTEM IS EXPECTED TO MOVE INTO NORTHERN ALASKA THIS WEEK. SNOWFALL WILL BE LIMITED TO FLURRIES ON THE ARCTIC SLOPE. THE REST OF THIS WEEK WILL BE SNOW FREE IN THE INTERIOR...WHICH HAS A RELATIVELY THIN SNOW COVER. IT IS NOT QUITE A SNOW DROUGHT...BUT ANOTHER WEEK OF NO SNOWFALL WILL CONTINUE IN THAT DIRECTION. THE STATISTICS ARE IN THE PUBLIC INFORMATION STATEMENT ON THE FAIRBANKS WEATHER PAGE... PAFG.ARH.NOAA.GOV. EARLY MORNING POLAR ORBITING SATELLITE IMAGERY SHOWS OVERCAST LOW CLOUDS OVER THE ARCTIC SLOPE FROM PRUDHOE BAY WESTWARD TO POINT HOPE. THE CLEAR SKIES EAST OF PRUDHOE BAY ARE EXPECTED TO CLOUD OVER AND GET SOME SNOW FLURRIES LATER TODAY. ALSO ON THIS MORNINGS IMAGERY...THE LOW CLOUDS OVER THE YUKON FLATS ARE STILL THERE...BUT COVER A LITTLE LESS AREA NOW THAN YESTERDAY MORNING. TEMPERATURES IN NORTHERN ALASKA HAD BEEN NEAR OR ABOVE NORMAL LAST WEEK...BUT HAVE SINCE SETTLED DOWN TO SOMEWHAT BELOW NORMAL THROUGHOUT THE INTERIOR. THE BERING SEA COAST AND ARCTIC COASTAL PARTS OF THE REALM HAVE HAD ABOVE NORMAL TEMPERATURES FOR SOME TIME. THIS IS PARTICULARLY TRUE IN THE ARCTIC...IN LARGE PART DUE THE CONTINUED LARGE EXPANSE OF OPEN WATER WHICH EXTENDS FROM 150 MILES TO L40 MILES OFFSHORE FROM THE COAST. COASTAL HAZARD POTENTIAL DAYS 3 AND 4 /THURSDAY AND FRIDAY/...NONE && .AFG WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY FOR PKZ210. && $$ TF OCT 12 ______________________________________________________________________ PAFG - Reference: ['reported such weather. no new polar orbiting satellite imagery has'] 983 FXAK69 PAFG 241418 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 618 AM AKDT WED OCT 24 2012 .DISCUSSION... THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS HAVE SIMILAR FORECASTS THROUGH FRIDAY MORNING. STRONG HIGH PRESSURE ALOFT NOW COVERING THE EASTERN BERING SEA IS FORECAST TO EXPAND WESTWARD OVER ALL OF THE NORTHERN BERING SEA DURING THE NEXT THREE DAYS. HIGH PRESSURE AT THE SURFACE PRESENTLY COVERS ALL OF THE ALASKA INTERIOR AND IS PREDICTED TO EXPAND WESTWARD...AND TO COVER ALL OF THE NORTHERN BERING SEA BY FRIDAY. THE ONLY PART OF NORTHERN ALASKA WITH MUCH IN THE WAY OF CLOUD COVER IS THE ARCTIC. SOME LIGHT SNOW AND FAIRLY WIDESPREAD FOG HAVE COVERED THE AREA FOR THE PAST SEVERAL DAYS. BRIEF FREEZING DRIZZLE WAS OBSERVED AT NUIQSUT /ON THE CENTRAL ARCTIC COAST/ IN THE EARLY HOURS OF THIS MORNING. THE PATTERN FOR THIS BEGAN TO SET UP ON SATURDAY /OCTOBER 20/ AS A LOW PRESSURE SYSTEM MOVED UP THROUGH THE CENTRAL BERING SEA. THE WARM SECTOR OF THE FRONTAL SYSTEM AHEAD OF THIS LOW ADVANCED NORTHEASTWARD ON SATURDAY...AND GRADUALLY ADVANCED EASTWARD OVER THE ENTIRE ALASKAN ARCTIC COASTAL REGION. BY TUESDAY NIGHT...THE WARM SECTOR REACHED THE YUKON BORDER. WEST WINDS ALOFT IN THE WARM SECTOR CARRIED AN AIR MASS THAT HAD ORIGINATED IN THE CENTRAL BERING SEA OVER SHALLOW ARCTIC AIR OVER ALASKAS NORTH SLOPE...CREATING THE FREEZING DRIZZLE. A SHORT WAVE ALOFT MOVING EASTWARD OVER THE ARCTIC SLOPE OF ALASKA ON THURSDAY MAY BRING SOME LIGHT SNOW. THE WEATHER FRONT WITH THIS FEATURE WILL MOVE EASTWARD OVER THE ALASKA ARCTIC COAST ON THURSDAY AND THURSDAY NIGHT. THE WEST WINDS FOLLOWING THE FRONT ARE EXPECTED TO BE ABOUT 25 MPH. THIS IS NOT EXPECTED TO BRING ANY SURF RELATED PROBLEMS...LARGELY BECAUSE THE ARCTIC COAST EAST OF BARROW HAS EXTENSIVE SHOREFAST ICE. THE ONSHORE WINDS THIS LOW WILL BRING TO THE COAST FROM BARROW TO POINT LAY ON FRIDAY WILL NOT BE OVER 20 MPH BEYOND 12 HOURS...NOT ENOUGH TIME TO BUILD UP MUCH SURF. A NEW LOW WHICH HAS NOW MOVED NORTHWARD OUT OF SIBERIA NEAR LONGITUDE 165 DEGREES EAST. THIS CLOSELY MATCHES THE GFS MODEL FORECAST. THE GFS MODEL FORECASTS THIS NEW LOW TO CIRCUMNAVIGATE THE CHUKCHI SEA...AND TO MOVE SOUTHEASTWARD THROUGH THE BEAUFORT SEA THURSDAY NIGHT...AND TO REACH MACKENZIE BAY FRIDAY. THE WEST WINDS THIS LOW WILL BRING TO THE EASTERN ARCTIC COAST ON THURSDAY AND THURSDAY NIGHT WILL WILL LEAVE THE EASTERN ARCTIC COAST OF ALASKA AGAIN UNSCATHED BECAUSE OF THE BARRIER OF SHOREFAST ICE. A FAIRLY STRONG LOW PRESSURE SYSTEM REACHED THE SOUTHERN KAMCHATKA PENINSULA LATE YESTERDAY EVENING. THE ENERGY WITH THIS LOW IS FORECAST BY THE GFS MODEL TO MOVE NORTHWARD...ON THE PERIMETER OF THE HIGH PRESSURE ALOFT OVER THE BERING SEA. THIS LOW MAY FOLLOW ITS PREDECESSOR...MOVING AROUND THE CHUKCHI SEA ON FRIDAY...AND INTO THE EASTERN BEAUFORT SEA SATURDAY NIGHT. ONCE AGAIN...SHOREFAST ICE ON THE ALASKAN ARCTIC COAST WILL SERVE AS A BARRIER TO THE WAVES THIS LOW RAISES IN THE ARCTIC COASTAL WATERS OF ALASKA. THE FETCH OF OPEN WATERS NORTH OF THE ALASKAN ARCTIC COAST IS STILL LARGE...FROM 150 TO 400 MILES...BUT CAN BE EXPECTED TO GRADUALLY SHRINK OVER THE NEXT SEVERAL WEEKS. THE EXTENDED CLEAR WEATHER OVER THE INTERIOR LOOKS LIKE IT WILL LAST THROUGH MONDAY OF NEXT WEEK. TEMPERATURES THROUGHOUT NORTHERN ALASKA WILL BE ON A GRADUAL DOWNWARD PATH. SO FAR...THE COLDEST TEMPERATURES IN NORTHERN ALASKA THIS MONTH HAVE REACHED 20 TO 25 BELOW IN THE NORTHEASTERN INTERIOR. SOME 30 BELOW READINGS ARE POSSIBLE THERE BY THE END OF THIS WEEK. LOW CLOUDS AND PATCHY FOG HAVE CONTINUED TO FORM NEAR RIVERS IN THE INTERIOR...MAINLY IN THE EARLY MORNING HOURS. THE AREA COVERED BY THESE CLOUDS AND PATCHY FOG HAS BEEN SHRINKING FOR THREE DAYS NOW. EARLY THIS MORNING...EAGLE...NORTHWAY AND FORT YUKON HAVE REPORTED SUCH WEATHER. NO NEW POLAR ORBITING SATELLITE IMAGERY HAS COME IN YET THIS MORNING. GEOSTATIONARY SATELLITE IMAGERY SHOWS A CIRCULAR AREA OF LOW CLOUDS ABOUT 100 MILES IN DIAMETER MOVING SOUTHWESTWARD OUT OF THE CENTRAL YUKON TERRITORY. THESE REACHED EAGLE AND NORTHWAY AROUND 2 AM THIS MORNING. THE GFS MODEL FORECASTS A NEW SURFACE LOW PRESSURE SYSTEM TO COASTAL HAZARD POTENTIAL DAYS 3 AND 4 /FRIDAY AND SATURDAY/...NONE && .AFG WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY FOR PKZ225-PKZ230. && $$ TF OCT 12 ______________________________________________________________________ PAFG - Reference: ['todays polar orbiting satellite imagery shows blurred areas of'] 871 FXAK69 PAFG 012359 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 359 PM AKDT THU NOV 1 2012 .DISCUSSION... BOTH THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS FORECAST LOW PRESSURE ALOFT OVER THE BEAUFORT SEA TO SEND A SHORT WAVE FROM THE WESTERN ALASKA ARCTIC SLOPE TO THE YUKON BORDER BY SATURDAY AFTERNOON. THE GFS FORECASTS A WEAKER SHORT WAVE ALOFT TO MOVE SOUTHWARD OVER THE EASTERN ALASKAN NORTH SLOPE SATURDAY NIGHT THROUGH SUNDAY. THIS SYSTEM IS NOT EXPECTED TO BRING VIGOROUS WINTER WEATHER TO THE ALASKAN ARCTIC AS ITS PREDECESSOR HAS. LOW PRESSURE ALOFT WILL REMAIN OVER THE EASTERN INTERIOR THROUGH MONDAY. THE GFS MODEL FORECASTS LARGE HIGH PRESSURE ALOFT OVER SIBERIA AND THE WESTERN BERING SEA TO BUILD OVER WESTERN ALASKA MONDAY AND TUESDAY. OVERALL...STRONG NORTH FLOW FROM THE ARCTIC WILL PREVAIL OVER WESTERN ALASKA FOR THE NEXT 5 DAYS. THE PATTERN OVER THE EASTERN AND CENTRAL INTERIOR WILL BE DIFFERENT. WEAK LOW PRESSURE WILL PREVAIL THERE THROUGH THE WEEKEND. THIS CIRCULATION LEAVES THE EASTERN INTERIOR OPEN TO INFLUXES OF MOISTURE FROM A LARGE LOW PRESSURE AREA OVER THE GULF OF ALASKA...STARTING FRIDAY NIGHT AND THROUGH THE WEEKEND. THEREFORE...THIS AFTERNOONS FORECASTS INCLUDE SNOW IN THE EASTERN INTERIOR AND ESPECIALLY IN THE EASTERN ALASKA RANGE. THE WEATHER FRONT NOW OVER THE WESTERN AND CENTRAL ALASKAN ARCTIC COAST WILL MOVE SOUTHWARD OVER THE INTERIOR FRIDAY NIGHT AND SATURDAY. IT WILL WEAKEN CONSIDERABLY ONCE IT IS SOUTH OF THE BROOKS RANGE. NONETHELESS...BRISK NORTHEAST WINDS OVER HIGHLAND SUMMITS ARE EXPECTED TO FOLLOW THE FRONT FRIDAY NIGHT THROUGH SATURDAY NIGHT. STRONG CIRCULATION ON THE NORTHWEST PERIMETER OF THE LARGE GULF OF ALASKA LOW WILL REACH THE BERING SEA COAST OF NORTHERN ALASKA FRIDAY AND DIMINISH SATURDAY NIGHT AS THE LOW WEAKENS. FREEZE UP ON THE ARCTIC COASTAL WATERS IS RAPIDLY IN PROGRESS. MUCH OF THE CHUKCHI SEA IS ALREADY ICE COVERED. BY MONDAY /NOVEMBER 5/...THE AREA OF ICE FREE WATERS IN THE BEAUFORT SEA IS EXPECTED TO BE ABOUT ONE HALF OF ITS PRESENT EXTENT. SHOREFAST ICE WILL BE IN PLACE OVER ALL OF THE ALASKAN ARCTIC COAST FROM DEMARCATION POINT TO CAPE LISBURNE. TODAYS POLAR ORBITING SATELLITE IMAGERY SHOWS BLURRED AREAS OF FAIRLY UNIFORM INFRARED TEMPERATURES OVER THE NORTH AND WESTERN INTERIOR. THESE ARE ASSOCIATED WITH BRISK NORTHEAST WINDS ABOVE THE BOUNDARY LAYER. COASTAL HAZARD POTENTIAL DAYS 3 AND 4 /SUNDAY AND MONDAY/...NONE && .AFG WATCHES/WARNINGS/ADVISORIES... HEAVY FREEZING SPRAY WARNING FOR PKZ200-PKZ210-PKZ220-PKZ225- PKZ230-PKZ235-PKZ240-PKZ245. SMALL CRAFT ADVISORY FOR PKZ200-PKZ210-PKZ225-PKZ235-PKZ240- PKZ245. && $$ TF NOV 12 ______________________________________________________________________ PAFG - Reference: ['the recent polar orbiting satellite imagery over the arctic'] 494 FXAK69 PAFG 040000 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 400 PM AKDT SAT NOV 3 2012 .DISCUSSION... THE LARGE TROUGH OF LOW PRESSURE ALOFT EXTENDING SOUTHWARD FROM THE EAST BEAUFORT SEA TO THE SOUTHEAST INTERIOR WILL REMAIN LARGELY IN PLACE UNTIL EARLY TUESDAY...AT WHICH TIME WESTERLY WINDS ALOFT PUSH IN FROM THE BERING SEA AND SIBERIA. THE NAM AND GFS COMPUTER WEATHER FORECAST MODELS HAVE SIMILAR PROJECTIONS ON THIS PART OF THE FORECASTS. THE GFS MODEL FORECASTS THE STRONG HIGH PRESSURE ALOFT AND AT THE SURFACE TO SHIFT EASTWARD...AND TO BE OVER THE EASTERN ALASKA MAINLAND LATE NEXT WEEK. TO THE WEST...THE GFS MODEL FORECASTS A STRONG LOW PRESSURE SYSTEM TO MOVE FROM WESTERN ALEUTIANS INTO THE NORTH BERING SEA LATE NEXT WEEK. THIS LOOKS REASONABLE...AND IF THE FORECAST IS TRUE...THERE WILL BE ROUGH WEATHER IN THE WEST LATE NEXT WEEK. BEYOND NEXT WEEKEND...THE MODELS DIVERGE GREATLY...WHICH IS OFT THE CASE. AT THE SURFACE...A COLD FRONT ALOFT EXTENDS FROM THE LOWER MACKENZIE VALLEY TO THE WESTERN ALASKA RANGE. THIS SYSTEM IS NEARLY STATIONARY. SNOW IS FALLING OVER MOST OF THE AREA ALONG AND SOUTH OF IT. HIGH PRESSURE HAS BEEN BUILDING FROM SIBERIA OVER THE NORTHWEST ALASKA COAST. STRONG LOW PRESSURE REMAINS OVER THE GULF OF ALASKA. THIS MATCH UP IS EXPECTED TO LAST INTO EARLY MONDAY...AND WILL CONTINUE TO BRING BRISK NORTHEAST WINDS TO MUCH OF THE REALM SOUTH OF THE BROOKS RANGE. A RATHER WEAK LOW PRESSURE SYSTEM IS MOVING EASTWARD AT ABOUT 25 MPH THROUGH THE NORTH CHUKCHI SEA. THE WEATHER FRONT EXTENDING SOUTHWEST FROM THE LOW IS EXPECTED TO REACH THE WESTERN ARCTIC COAST OF ALASKA LATE TONIGHT. THE RECENT POLAR ORBITING SATELLITE IMAGERY OVER THE ARCTIC SUGGESTS THAT ANOTHER WEAK IMPULSE BEHIND THIS FRONT IS NOW FORMING OVER THE FAR WEST CHUKCHI SEA. POLAR IMAGERY OVER THE MAINLAND SHOWS CLEAR SKIES OVER MUCH OF THE BROOKS RANGE AND OVER THE WEST COAST FROM KIVALINA SOUTHWARD OVER KOTZEBUE SOUND...THE SEWARD PENINSULA...NORTON SOUND...AND THE YUKON DELTA. THE LENTICULAR CLOUDS IN THE LEE /SOUTH SIDE/ OF THE WEST SEWARD PENINSULA AND SAINT LAWRENCE ISLAND EVIDENCE THE BRISK NORTHERLY FLOW OVER THOSE AREAS. COASTAL HAZARD POTENTIAL DAYS 3 AND 4 ...NONE && .AFG WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FOR AKZ222. WINTER WEATHER ADVISORY FOR AKZ220. HEAVY FREEZING SPRAY WARNING FOR PKZ200-PKZ210-PKZ220-PKZ225- PKZ230-PKZ235-PKZ245. SMALL CRAFT ADVISORY FOR PKZ200-PKZ210. && $$ TF NOV 12 ______________________________________________________________________ PAFG - Reference: ['todays polar orbiting satellite imagery showed that the cold front'] 283 FXAK69 PAFG 050058 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 358 PM AKST SUN NOV 4 2012 .DISCUSSION... THE GFS AND NAM COMPUTER WEATHER FORECAST MODELS OFFER SIMILAR FORECASTS OUT THROUGH TUESDAY AFTERNOON. THE LARGE TROUGH OF LOW PRESSURE ALOFT NOW EXTENDING FROM THE EASTERN BEAUFORT SEA OVER THE ALASKA MAINLAND TO THE WESTERN GULF OF ALASKA WILL HOLD PLACE THROUGH MONDAY...AND THEN EXIT TO THE YUKON TERRITORY AND THE EASTERN GULF OF ALASKA ON TUESDAY. AS THAT HAPPENS...STRONG HIGH PRESSURE AT THE SURFACE AND ALOFT NOW OVER THE WESTERN BERING SEA AND CHUKOTKA WILL BUILD OVER THE BROOKS RANGE AND THE WEST COAST OF ALASKA. VIGOROUS SOUTHWESTERLY FLOW ALOFT WILL DEVELOP OVER THE RUSSIAN FAR EAST AND REACH THE ALASKAN ARCTIC MONDAY NIGHT AND TUESDAY...AND THEN WEAKEN WEDNESDAY NIGHT AND THURSDAY. THE ARCTIC WILL CONTINUE TO HAVE RATHER ACTIVE WEATHER DUE TO A SERIES OF DISTURBANCES MOVE THROUGH IN WESTERLY FLOW OVER THE NEXT THREE DAYS. THE FIRST SUCH SYSTEM IS A COLD FRONT THAT CAME ASHORE ON THE WESTERN ARCTIC COAST TODAY...AND IS DUE TO REACH THE EASTERN BEAUFORT SEA LATE TONIGHT. AS THIS FRONT PASSED INLAND THIS AFTERNOON...NORTHWEST WINDS GUSTING TO 25 MPH ACCOMPANIED BY SNOW SHOWERS DEVELOPED FROM CAPE HALKETT TO CAPE LISBURNE. THE NEXT ARCTIC SYSTEM IS A LOW PRESSURE SYSTEM IN THE WESTERN CHUKCHI SEA...WITH A WEATHER FRONT EXTENDING SOUTHWARD INTO CENTRAL SIBERIA. THE WEATHER FRONT IS EXPECTED TO REACH THE ALASKA NORTHWEST COAST TUESDAY MORNING. THIS SYSTEM IS EXPECTED TO HAVE STRENGTH SIMILAR TO THAT ITS PREDECESSOR HAD TODAY. BOTH THE GFS AND NAM MODELS FORECAST A RATHER SMALL LOW ALOFT TO MOVE EASTWARD OVER THE PRIBILOFS TUESDAY EVENING...AND TO DISSIPATE OVER THE YUKON DELTA WEDNESDAY EVENING. THUS...THE YUKON DELTA FORECAST FOR A CHANCE OF SNOW WEDNESDAY NIGHT. THE GFS MODEL FORECASTS A NEW AND STRENGTHENING LOW AT THE SURFACE AND ALOFT TO MOVE FROM THE RUSSIAN FAR EAST TO CAPE NAVARIN /ON THE COAST OF THE WESTERN BERING SEA/ ON WEDNESDAY NIGHT. THIS LOW IS PREDICTED TO REACH THE PRIBILOFS ON FRIDAY...AND BRISTOL BAY SATURDAY NIGHT. BRISK NORTH WINDS WILL RESUME OVER THE WEST COAST ON SATURDAY AS THE LOW PASSES BY. COLDER TEMPERATURES WILL DEVELOP OVER NORTHERN ALASKA FOR THE NEXT 36 HOURS...BUT WEST COAST TEMPERATURES WILL RISE SOME TUESDAY AND WEDNESDAY. BY THE END OF THE WEEK...TEMPERATURES WILL BE BELOW NORMAL NEARLY EVERYWHERE IN THE REALM...PARTICULARLY IN THE INTERIOR. FREEZEUP IN THE ALASKAN SECTOR OF THE ARCTIC OCEAN IS NEARLY COMPLETE. KOTZEBUE SOUND BECAME ICED IN OCTOBER 31-NOVEMBER 1. TODAYS POLAR ORBITING SATELLITE IMAGERY SHOWED THAT THE COLD FRONT THAT CAME ASHORE ON THE WESTERN ARCTIC COAST HAD MORE STRENGTH ALOFT THAN AT THE SURFACE...WHERE THE DATA DID NOT INDICATE MUCH FLOW NEAR THE SURFACE. SCATTERED SNOW SHOWERS COVERED THE CHUKCHI SEA BETWEEN BARROW AND POINT HOPE...FROM THE COAST TO ABOUT 200 MILES OFFSHORE. OVERCAST STRATUS AND STRATOCUMULUS ENVELOPED THE RUSSIAN SECTOR OF THE CHUKCHI SEA AND THE BERING SEA WEST OF NOME AND CAPE MOHICAN. THE REMAINS OF AN EARLIER ARCTIC COLD FRONT THAT MOVED ASHORE THE ALASKAN ARCTIC COAST ON THURSDAY...AND WHICH HAVE MOVED VERY LITTLE SINCE FRIDAY NIGHT...ARE WEAKENING OVER THE SOUTHEAST HALF OF THE INTERIOR. SNOW CONTINUES TO FALL IN THIS AREA...BUT IS EXPECTED TO DIMINISH OVER THE NEXT TWO DAYS. COASTAL HAZARD POTENTIAL DAYS 3 AND 4 /WEDNESDAY AND THURSDAY/...NONE && .AFG WATCHES/WARNINGS/ADVISORIES... HEAVY FREEZING SPRAY WARNING FOR PKZ200-PKZ210-PKZ220-PKZ225- PKZ230-PKZ240-PKZ245. SMALL CRAFT ADVISORY FOR PKZ220-PKZ225-PKZ245. && $$ TF NOV 12 ______________________________________________________________________ PAFG - Reference: ['the canadian archipelago and you can see stratus on the poes sat'] 063 FXAK69 PAFG 292047 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 1147 AM AKST THU NOV 29 2012 .DISCUSSION... MODELS...ONCE AGAIN FAIRLY GOOD AGREEMENT ON THE OVERALL PICTURE BUT A BIT WEAK IN THE DETAILS. MODELS ARE COMING TOGETHER IN THE EXTENDED PERIODS AS WE SEE A CHANGE IN THE PATTERN. ALOFT...AT 500 HPA...RIDGE OF HIGH PRESSURE WITH A 562 DAM CENTER LOCATED OVER THE CENTRAL ALEUTIAN CHAIN EXTENDS NORTH THROUGH THE BERING STRAIT. THE RIDGE WEAKENS SATURDAY AS A SHORTWAVE MOVES ACROSS THE TOP OF IT. THE RIDGE THEN SLIDES TO THE WESTERN BERING SEA SUNDAY AND STRENGTHENS. A TROUGH OF LOW PRESSURE EXTENDS SOUTHWEST FROM A LOW OVER THE CANADIAN ARCHIPELAGO TO SOUTH CENTRAL ALASKA THEN SOUTH TO A LOW IN THE NORTHWEST PACIFIC. AT 850 HPA...OVERALL NO SIGNIFICANT CHANGES WITH TEMPERATURES THROUGH THE WEEKEND WITH THE EXCEPTIONS BEING A COUPLE SHOTS OF SLIGHTLY COOLER AIR IN THE EASTERN INTERIOR...AND EXPECT SOME COLD AIR TO POOL ON THE NORTH SIDE OF THE EASTERN ALASKA RANGE. AS WE HEAD INTO NEXT WEEK SIGNIFICANT COOLING IS SHOWING UP IN THE MODELS AND IT WORKS ITS WAY WEST TO THE COAST. TEMPERATURES AS COLD AS MINUS 32C AT 850 HPA ARE SHOWING UP OVER THE FORTYMILE COUNTRY BY MIDWEEK. SURFACE...HIGH PRESSURE REMAINS OVER MAINLAND ALASKA. A SERIES OF SHORTWAVES CONTINUES TO WORK SOUTH FROM THE HIGH ARCTIC TO THE NORTHEAST ARCTIC COAST AND WILL PRODUCE MAINLY FLURRIES AND PERIODIC GUSTY WINDS. A FRONT ASSOCIATED WITH A SHORTWAVE ALOFT WILL APPROACH THE NORTHWEST COAST ON FRIDAY BUT IT LOSES MOST OF ITS PUNCH AS IT GETS TO THE COAST THEN MOVES SOUTHEAST ACROSS THE WESTERN INTERIOR AND DISSIPATES. SOME GRADIENT ASSOCIATED WITH THE SYSTEM WILL KICK UP WINDS AROUND POINT HOPE AND MAYBE THROUGH THE BERING STRAIT...BUT NOT EXPECTING MUCH. STRONG GRADIENT REMAINS OVER THE SOUTH SLOPES OF THE ALASKA RANGE TO THE GULF AND WILL NOT CREATE ANY ISSUES FOR OUR AREA. ARCTIC COAST...WEAK FRONTS CONTINUE TO SWING AROUND THE LOW IN THE CANADIAN ARCHIPELAGO AND YOU CAN SEE STRATUS ON THE POES SAT PICTURES EXTENDING TO ABOUT 76N. EAST OF POINT LAY...FLURRIES WILL BE BROKEN UP BY PERIODS OF SNOW BUT DO NOT EXPECT MUCH ACCUMULATION. STRATUS SHOULD REMAIN NORTH OF THE BROOKS RANGE THOUGH A LITTLE COULD BLEED THROUGH. ON THE NORTHEAST COAST SOME GUSTY WINDS WITH THE FRONTS AS THEY MOVE THROUGH BUT WINDS PREDOMINATELY LESS THAN 15 KT. ON THE NORTHWEST COAST A SHOT OF SNOW FRIDAY NIGHT BUT WILL BE SHORT LIVED. WEST COAST...PRETTY QUIET STILL. SOME STRATUS THROUGH THE BERING STRAIT AND OVER ST LAWRENCE ISLAND...BUT OTHERWISE MOSTLY CLEAR. A SHORT PERIOD OF SNOW OR FLURRIES AROUND POINT HOPE FRIDAY NIGHT BUT SYSTEM WILL FALL APART PRETTY RAPIDLY SO EXPECTING JUST FLURRIES AS THE SYSTEM MOVES INLAND AND DISSIPATES. INTERIOR...MOSTLY CLEAR CONTINUES. EXPECT TEMPERATURES TO COOL SLIGHTLY THE NEXT COUPLE DAYS...BUT OVERALL NOT CHANGE MUCH. COLDEST TEMPERATURES WILL BE ALONG THE ALCAN BORDER EAST OF FORT YUKON AND IN THE FORTYMILE COUNTRY THIS WEEKEND. EVEN COLDER TEMPERATURES ARE ON THE WAY NEXT WEEK UNLESS WE CAN GET SOME CLOUDS MOVING THROUGH THE AREA. WINDS WILL REMAIN LIGHT. INVERSIONS AROUND TOWN NOT EXPECTED TO CHANGE MUCH SO CONTINUED WARMER IN THE HILLS THROUGH THE WEEKEND. MIDRANGE...MODELS SIGNAL A CHANGE MID WEEK AND BEYOND FROM THE PATTERN WE HAVE BEEN BLOCKED INTO BUT IT WILL NOT BE A WARMING TREND. WE WILL HAVE SOME POTENTIAL FOR WARMER TEMPERATURES IF THE DOMINANT LOW IN THE GULF MOVES FAR ENOUGH NORTH TO BRINGS SOME WINDS ALOFT TO THE AREA AND BREAK UP THE INVERSION...BUT AT THIS TIME THAT IS QUESTIONABLE. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .AFG WATCHES/WARNINGS/ADVISORIES... BRISK WIND ADVISORY FOR PKZ245. && $$ SDB NOV 12 ______________________________________________________________________ PAFG - Reference: ['polar orbiting satellite imagery over night has shown the overcast'] 662 FXAK69 PAFG 081515 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 615 AM AKST SAT DEC 8 2012 .DISCUSSION... THE PATTERN OF COLD FLOW FROM THE NORTH THAT HAS PERSISTED FOR MOST OF THE PAST 3 WEEKS OVER NORTHERN ALASKA HAS ENDED. A SERIES OF DISTURBANCES FROM THE WEST IS EXPECTED TO BECOME A ESTABLISHED OVER NORTHERN ALASKA STARTING SUNDAY...AND TO CONTINUE FOR MOST OF THE WEEK. THE GEOSYNCHRONOUS WEATHER SATELLITE IMAGERY SHOWS A LARGE FRONTAL CLOUD BAND ABOUT 400 MILES WIDE EXTENDING FROM THE SOUTHEAST BERING SEA TO THE CENTRAL GULF OF ALASKA. THIS CLOUD MASS HAS BEEN MOVING NORTH...AND ITS LEADING EDGE IS UP TO 60 DEGREES NORTH LATITUDE...OVER THE SOUTHERN MAINLAND OF ALASKA. THE FLOW ALOFT OVER THE ALASKA RANGE INTO NORTHERN ALASKA IS NOT EXPECTED TO BE AT ALL STRONG...SO TEMPERATURES IN THE INTERIOR ARE NOT FORECAST TO RISE DRAMATICALLY AS WOULD BE EXPECTED WITH A WINTER TIME CHINOOK. INSTEAD...THE INBOUND WEATHER FOR MOST OF THE INTERIOR WILL BE SNOW...MOST LIKELY TO BEGIN LATE TONIGHT AND SUNDAY AS THE INBOUND POLAR MARITIME AIR FLOWS OVER THE ARCTIC AIR IN THE CENTRAL AND EASTERN INTERIOR. THE SNOW IS EXPECTED TO END MONDAY NIGHT AND TUESDAY. MORE SUBSTANTIAL SNOWFALL IS EXPECTED OVER THE WEST COASTAL ZONES STARTING TUESDAY AFTERNOON AND NIGHT AS A STRONG LOW PRESSURE SYSTEM MOVES FROM THE CENTRAL BERING SEA ON TUESDAY...AND THEN REACHES THE YUKON DELTA WEDNESDAY EVENING. ON WEDNESDAY THE AREA OF SNOWFALL IS EXPECTED TO EXPAND OVER ALL OF THE INTERIOR EXCEPT THE EASTERN ALASKA RANGE AND THE FORTYMILE COUNTRY. THE LARGEST SNOWFALL AMOUNTS ARE LIKELY TO BE IN THE SOUTHWESTERN INTERIOR. POLAR ORBITING SATELLITE IMAGERY OVER NIGHT HAS SHOWN THE OVERCAST STRATOCUMULUS CLOUDS OVER THE NORTH SLOPES OF THE BROOKS RANGE AND THE YUKON FLATS DECREASING IN EXTENT. THE CLOUDS OVER THE YUKON FLATS MOVED NORTHWESTWARD...AND REACHED FORT YUKON SHORTLY AFTER MIDNIGHT. SKIES SHOULD CLEAR THERE THIS MORNING. THE STRONG NORTHEAST WINDS OVER THE WEST COAST ZONES FROM THE YUKON DELTA TO CAPE LISBURNE ARE EXPECTED TO REACH PEAK STRENGTH TONIGHT...AND TO BEGIN DECREASING SUNDAY. TEMPERATURES OVER THE COASTAL WATERS FROM BERING STRAIT TO SOUTH OF SAINT LAWRENCE ISLAND RANGE FROM ZERO TO 15 ABOVE. THIS...ALONG WITH GALE FORCE NORTH WINDS...WILL CONTINUE TO CREATE HEAVY FREEZING SPRAY SOUTH OF THE EDGE OF THE PACK ICE...WHICH HAS BEEN ADVANCING RAPIDLY SOUTHWARD ALL WEEK. THE RAPID EXPANSION OF PACK ICE OVER THE CHUKCHI AND BERING SEAS IN THE EARLY WINTER THIS YEAR IS SIMILAR TO WHAT OCCURRED IN 2010 AND 2011. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .AFG WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY FOR AKZ223. WINTER WEATHER ADVISORY FOR AKZ214. HIGH WIND WARNING FOR AKZ213. HEAVY FREEZING SPRAY WARNING FOR PKZ210. GALE WARNING FOR PKZ210. BRISK WIND ADVISORY FOR PKZ200-PKZ220-PKZ225-PKZ245. && $$ TF DEC 12 ______________________________________________________________________ PAFG - Reference: ['afternoons polar orbiting satellite imagery as a solid band of'] 156 FXAK69 PAFG 180145 AFDAFG NORTHERN ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FAIRBANKS AK 445 PM AKST MON DEC 17 2012 .DISCUSSION... BOTH THE GFS AND NAM COMPUTER WEATHER FORECAST MODELS HAVE UNDER ESTIMATED THE STRENGTH OF A STRONG LOW PRESSURE SYSTEM WHICH MOVED THROUGH THE CENTRAL BERING SEA LAST NIGHT AND OVER NOME JUST AFTER 2 PM THIS AFTERNOON. THE STRONGEST REPORTED WINDS WERE EAST AT 50 MPH AT UNALAKLEET EARLY THIS MORNING. THE LOW IS FORECAST TO REACH THE WESTERN BROOKS RANGE EARLY TUESDAY...AND THEN TO WEAKEN NORTH OF THE CENTRAL ARCTIC COAST IN THE AFTERNOON AND EVENING. THE WEATHER FRONT AHEAD OF THIS BERING SEA LOW APPEARS ON THIS AFTERNOONS POLAR ORBITING SATELLITE IMAGERY AS A SOLID BAND OF CLOUDS ABOUT 150 MILES WIDE OVER THE WESTERN INTERIOR. THERE ARE SCATTERED SNOW SHOWERS TO THE WEST OF THE FRONT OVER THE BERING SEA COAST AND KOTZEBUE SOUND REGIONS. BECAUSE OF THE MODEL UNDER FORECAST OF THE STRENGTH OF THIS LOW...THE WINTER WEATHER ADVISORIES FOR THE WEST COAST AND THE ARCTIC WERE FOR WEATHER MORE SEVERE THAN THE MODELS PREDICTED. SOUTHERLY FLOW OVER THE ALASKA RANGE INTO THE INTERIOR IS ALREADY IN PROGRESS OVER THE WESTERN ALASKA RANGE AND IS EXPECTED TO DEVELOP OVER THE EASTERN ALASKA RANGE THIS EVENING. AT ANTLER CREEK...LOCATED NEAR THE PARKS HIGHWAY IN THE WESTERN ALASKA RANGE...THE WIND IS SOUTH GUSTING TO 30 MPH AND THE WIND CHILL IS 40 BELOW. A STRONG TROUGH OF LOW PRESSURE ALOFT IS NOW BEGINNING TO MOVE IN OVER THE WESTERN INTERIOR...AND IS FORECAST TO EXTEND FROM PRUDHOE BAY TO DENALI PARK WEDNESDAY EVENING. THERE WILL BE WIDESPREAD SNOW AHEAD OF AND ALONG THIS DISTURBANCE. COLD TEMPERATURES CONTINUE PREVAIL OVER THE INTERIOR. THE LOW TEMPERATURE AT FORT YUKON WAS 56 BELOW EARLY THIS MORNING. TEMPERATURES ARE RISING IN THE WEST. THE LARGEST RISES HAVE BEEN AT STATIONS ON THE VALLEY FLOORS WHERE SOME LIGHT WINDS HAVE DEVELOPED. FOR EXAMPLES...NENANA UP 26 DEGREES /FROM 49 BELOW AT MIDNIGHT TO 23 BELOW NOW/...AT MCGRATH UP 18 DEGREES /FROM 44 BELOW THIS MORNING TO 26 BELOW NOW./ EAGLE SUMMIT...ON THE STEESE HIGHWAY BETWEEN FAIRBANKS AND CIRCLE CITY...REACHED 2 BELOW THIS AFTERNOON. THIS IS THE HIGHEST TEMPERATURE REPORTED IN THE INTERIOR TODAY...EAGLE SUMMIT IS AT AN ELEVATION CLOSE TO 3650 FEET ABOVE SEA LEVEL. THERE IS...HOWEVER...NOT STRONG ENOUGH INFLOW OF WARM AIR ALOFT TO BRING INTERIOR TEMPERATURES UP TO ZERO. TYPICAL TEMPERATURES ON TUESDAY WILL RANGE FROM 15 BELOW TO 35 BELOW. FOLLOWING THIS...COLD WEATHER IS EXPECTED TO RETURN TO MOST OF THE INTERIOR WEDNESDAY NIGHT. THE GFS MODEL FORECASTS A LOW NOW JUST EAST OF JAPAN TO MOVE RAPIDLY EAST AND TO REACH THE WEST END OF THE ALEUTIANS ON WEDNESDAY...AND TO BRING MODERATE SOUTHERLY FLOW AND WIDESPREAD SNOW TO THE WEST COAST OF NORTHERN ALASKA THURSDAY THROUGH FRIDAY. AS IN THE INTERIOR...COLD WEATHER WILL RESUME THERE SHORTLY AFTER THE MODERATION IN TEMPERATURES. COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE && .AFG WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY FOR AKZ201-AKZ202-AKZ203-AKZ204-AKZ205- AKZ206-AKZ219-AKZ221-AKZ223-AKZ225-AKZ226. DENSE FOG ADVISORY FOR AKZ222. WINTER WEATHER ADVISORY FOR AKZ209-AKZ210-AKZ213-AKZ216-AKZ217. GALE WARNING FOR PKZ210. BRISK WIND ADVISORY FOR PKZ200-PKZ210-PKZ215-PKZ220-PKZ225- PKZ230-PKZ235-PKZ240-PKZ245. && $$ TF DEC 12 ______________________________________________________________________ --- Site: PAJK --- PAJK - Reference: ['by current total precip water scans from the poes satellite that'] 399 FXAK67 PAJK 282338 AFDAJK SOUTHEAST ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JUNEAU AK 338 PM AKDT MON MAY 28 2012 .SHORT TERM...LITTLE CHANGE INCLUDING THE RAIN AND INCREASING WIND TUE. CONFIDENCE IS AVERAGE. STRONGEST WINDS ARE, HOWEVER, SHORTLY AFTER THE TRANSITION TO THE LONG RANGE SECTION. SEE BELOW. GOES IR LOOP FOR 600 NM S PAMD IS CONSISTENT WITH A ZONALLY TRACKING AND STRONG TRIPLE PT. THIS TRIPLE POINT FEATURE IS CYCLOGENETIC AND BEGINNING TO TURN TO THE NE. THE PARENT LOW IS 200 NM S OF PADU AND QUASISTATIONARY. 00Z WED THE CYCLOGENESIS OF THE TRIPLE PT SHOULD RESULT IN A 986 MB LOW ABOUT 300 NM S OF PAMD WITH A FRONTAL WAVE AT ABOUT 400 NM S OF PAYA. ALSO AT 00Z WED AN OCCLUDED FRONTAL BOUNDARY SHOULD EXTEND FROM THAT LOW IN THE SOUTH CENTRAL GULF TO A NEW TRIPLE POINT ABOUT 160 NM SW OF PAKT. WITH A FRONTAL WAVE AT ABOUT 300 NM SW OF PAKT. NOTE THE GALE FORCE WINDS DVLPG IN THE CLARENCE STRAIT AS WELL AS THE OUTSIDE WATERS TUE. THE SFC WINDS ASSOC WITH THE OFCNT WILL INCLUDE GUSTS AS HIGH AS 35 MPH REACHING LOCATIONS IN ZONE 27 SRN PNHDL TUE AFTN. SEE THE TABLE LISTING WARNINGS AND ADVISORIES BELOW. EC MODEL IS FASTER THAN GFS ON TRACK OF CYCLONE EVOLUTION APCHG SRN PNHDL. ASSUMING THE EC IS CORRECT, AND GIVEN THAT THE EC SHOWS A FOLLOWING WAVE, THE GFS SOLUTION CAN REPRESENT A SMOOTHING OF THE TRIPLE PT LOW AND THE FOLLOWING WAVE. THE NAM WAS BETWEEN THE EC AND GFS SOLNS, AND GIVEN IT'S SOLN IS CLOSER TO THE EC, WAS USED AS THE GUIDANCE FOR MANY FIELDS INCLUDING THE MSLP AND SFC WINDS. && .LONG TERM...EXTENDED PERIOD IS STILL LOOKING TO BE RATHER DAMP THROUGH AT LEAST LATE WEEK AS AN UPPER LEVEL TROUGH CONTINUES TO REMAIN ENTRENCHED OVER THE WESTERN GULF. AT THE SURFACE, A PERSISTENT LOW WILL ALSO BE MEANDERING AROUND THE WESTERN AND CENTRAL GULF DURING THIS PERIOD. FIRST CONCERN IN THE LONG TERM PERIOD IS WHAT HAPPENS WITH THE FRONT THAT IS MOVING THROUGH THE PANHANDLE TUES NIGHT. FORECAST MODELS ARE STILL HAVING A LITTLE ARGUMENT OVER HOW FAST THE FRONT WILL MOVE THROUGH THE AREA BUT GENERALLY ARE IN AGREEMENT ON STRUCTURE. GFS IS THE SLOW MODEL BEING ABOUT 2 TO 4 HOURS BEHIND THE EC, UK, AND NAM. GENERALLY BY TUES EVENING WINDS ALONG THE OUTSIDE WATERS WILL STILL BE BLOWING GALE FORCE BUT WILL START TO DIMINISH AS THE NIGHT GOES ON. SIMILARLY WIND IN THE INSIDE CHANNELS WILL BE AT THERE PEAK OR CLOSE TOO IT BY LATE TUES EVENING. WITH A DECENT LOW LEVEL JET AHEAD OF THE FRONT STRONG WIND HEADLINES MAY BE NEEDED FOR THE SOUTHERN PUBLIC ZONES TUES EVENING AND A GALE WARNING FOR CLARENCE STRAIT AS WELL. RAINFALL AMOUNTS WILL BE SOMEWHAT NOTEWORTHY, PARTICULAR FOR THE SOUTH, AS THE FRONT HAS RETAINED THE MOISTURE THAT IT STRIPED FROM TROPICAL STORM SANVU EARLIER THIS WEEKEND. THIS IS SUPPORTED BY CURRENT TOTAL PRECIP WATER SCANS FROM THE POES SATELLITE THAT SHOW A RATHER MOIST SYSTEM WITH SOME CONNECTIONS STILL REMAINING BACK TO THE REMAINS OF THE FORMER TROPICAL STORM. SOME AREAS IN THE SOUTHERN PANHANDLE MAY RECEIVE UP TO AN INCH OF RAIN OVER THE COURSE OF THE STORM. AREAS FARTHER NORTH MIGHT SEE A TENTH TO 4 TENTHS OF AN INCH DEPENDING ON LOCATION. FOLLOWING THE FRONT, THE PARENT LOW WILL SWING AROUND THE ALASKA PENINSULA WED BEFORE DRIFTING AROUND THE WESTERN AND CENTRAL GULF FOR THE REST OF THE WEEK. SHOWERS WILL PERSIST OVER THE PANHANDLE DURING THIS TIME DUE TO THE DEEP SW FLOW. THESE SHOWERS WILL BE ENHANCED BY SHORT WAVES (ONE APPEARING WED NIGHT INTO EARLY THURS AND ANOTHER EARLY FRI) PERIODICALLY THROUGH LATE WEEK. FORECAST BECOMES A BIT HARDER TO DISCERN BY NEXT WEEKEND AS OPERATIONAL MODELS START DISPLAYING SOME RATHER SIGNIFICANT DIFFERENCES. LONG RANGE MODELS WERE IN OK AGREEMENT THROUGH MOST OF THE PERIOD WITH THE SMALL EXCEPTION OF THE FRONT TUES NIGHT. DECIDED ON A BLEND OF NAM AND EC FOR THE MID RANGE AS BOTH LOOKED TO HAVE THE THE BEST AGREEMENT AND CONSISTENCY BETWEEN THEM. AS WELL AS THE FRONTAL STRUCTURE MADE SENSE BASED ON INTERACTIONS FROM JET PATTERNS. FARTHER OUT, TRANSITIONED TO MORE HPC DATA TO GET A GOOD MIDDLE GROUND SINCE OPERATIONAL MODELS ARE STILL A BIT JUMPY WITH THE SCENARIO FOR NEXT WEEKEND. FORECAST CONFIDENCE IS ABOUT AVERAGE. .AJK WATCHES/WARNINGS/ADVISORIES... PUBLIC...NONE. MARINE...GALE WARNING FOR PKZ036-041>043-051-052. SMALL CRAFT ADVISORY FOR PKZ021-022-033-035. && $$ JBT/EAL ______________________________________________________________________ PAJK - Reference: [' scatterometer winds from the polar orbiting ascat satellite'] 699 FXAK67 PAJK 301344 AFDAJK SOUTHEAST ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JUNEAU AK 544 AM AKDT MON JUL 30 2012 .SHORT TERM...AN UPPER LEVEL LOW OVER THE CENTRAL PANHANDLE ALONG WITH A WEAKENING SURFACE LOW OFF OF CAPE DECISION IS CAUSING SCATTERED SHOWERS ACROSS THE REGION THIS MORNING. THE ENERGY FROM THE UPPER LEVEL LOW WILL SHIFT NORTH THROUGH THE DAY AND THE SURFACE LOW WILL WEAKEN TO A TROUGH AS IT DRIFTS NORTHWARD BEFORE DISSIPATING AND BEING ABSORBED BY THE NEXT SYSTEM. THE NORTHWARD PROGRESSION OF BOTH OF THESE WILL CAUSE THE PERSISTENT SHOWERS CURRENTLY OVER THE KLAWOCK/KETCHIKAN AREAS TO BECOME MORE SCATTERED THROUGH THE DAY WITH SOME SUNNY BREAKS AND THE CENTRAL/NORTHERN AREAS WILL SEE SCATTERED SHOWERS INCREASE. THE COASTAL MOUNTAINS LOOK TO SEE MOST SHOWER ACTIVITY TODAY. AS THE LOW/TROUGH TO THE SOUTH DISSIPATES A RIDGE CURRENTLY OVER HECATE STRAIT AND HYDER AREA WILL BUILD OVER THE PANHANDLE AND CAUSE SOUTHERLY WINDS TO INCREASE THROUGH THE INSIDE WATERS. EXPECT WINDS OF UP TO 25KT THROUGH FAR NORTHERN LYNN CANAL NEAR TAIYA INLET BY THIS AFTERNOON. A LOW PRESSURE SYSTEM CURRENTLY OVER THE WESTERN GULF NEAR KODIAK ISLAND WILL MOVE ESE ACROSS THE GULF THROUGH THE DAY. RAIN ASSOC WITH THE FRONTAL BAND WILL REACH THE WESTERN PORTIONS OF THE YAKUTAT ZONE AND THE OUTSIDE WATERS LATE TONIGHT. WINDS THROUGH INSIDE WATERS WILL EASE THROUGH THE EVENING AS THE APPROACHING LOW PUSHES THE RIDGE AXIS SLIGHTLY TO THE EAST. EXPECT E-SELY WINDS TO INCREASE AS A RESULT. MID LEVEL FLOW WILL TURN MORE ONSHORE HOWEVER AND INCREASE SHOWERS TO LIKELY ALONG SW FACING SLOPES INCLUDING THE COASTAL MOUNTAINS AND THE JUNEAU AREA. SCATTEROMETER WINDS FROM THE POLAR ORBITING ASCAT SATELLITE OVERNIGHT SHOWED CALM TO VERY LIGHT WINDS OVER THE GULF AND SELY WINDS OF 10-15 KT OVER THE WESTERN GULF AHEAD OF THE NEXT SYSTEM. EXPECT THESE SELY WINDS TO MOVE INTO THE EASTERN GULF THROUGH THE DAY AND REACHING ABOUT 20 KT TONIGHT AS THE LOW MOVES INTO THE OFFSHORE AREA. MODELS WERE IN FAIR AGREEMENT AND USED AN ENSEMBLE APPROACH FOR MOST UPDATES. FORECAST CONFIDENCE IS ABOVE AVERAGE. .HYDROLOGY...LAKE NO LAKE ABOVE THE TAKU GLACIER HAS RELEASED. WATER TEMPERATURES FALLING MORE THAN THEIR DIURNAL NORMALS FIRST INDICATED THIS YESTERDAY MORNING. SINCE THEN WATER TEMPERATURES HAVE FALLEN FURTHER AND THE RIVER LEVELS HAVE STARTED RISING AT A CONSISTENT RATE. SINCE 10 AM AKDT SUNDAY THE RIVER HAS RISEN 1.36 FEET TO THE CURRENT STAGE OF 38.54 FEET AS OF 5 AM. AT THE CURRENT RATE AND FOLLOWING THE TYPICAL RELEASE VALUES AND TIME SPAN OF 2-3 DAYS THE RIVER WOULD CREST NEAR THE MINOR FLOOD STAGE OF 43 FEET BETWEEN TUESDAY NIGHT AND WEDNESDAY MORNING. SEE THE LATEST HYDROLOGIC STATEMENT (RVS) OR OTHER RELATED FLOOD PRODUCT FOR MOST UP TO DATE INFORMATION. && .LONG TERM...THE DAMP WEATHER CONTINUES INTO THE LONG RANGE PERIOD AS A SOMEWHAT WEAK SYSTEM ARRIVES IN THE PANHANDLE ON TUES. ARRIVING WITH IT IS MORE RAIN AND SOME WIND. HIGHEST RAINFALL AMOUNTS TUES INTO WED WILL BE IN THE SOUTHERN PANHANDLE AS THE BEST UPPER LEVEL FORCING WILL TRACK OVER THAT AREA AND THE SOUTHERLY LOW LEVEL FLOW FORCES SOME TERRAIN ENHANCEMENT. I EXPECT RAINFALL AMOUNTS UP TO AN INCH OVER THE COURSE OF THE WHOLE EVENT IN THE SOUTHERN PANHANDLE. AREAS FARTHER NORTH WILL SEE LIGHTER AMOUNTS DUE TO LESS FAVORABLE UPPER LEVEL DYNAMICS AND INCREASING DISTANCE FROM THE PARENT LOW. WINDS WITH THIS SYSTEM WILL ALSO PRESENT A FEW PROBLEMS. PRE- FRONTAL WINDS IN THE EASTERN GULF WILL BE STRONG ENOUGH TO WARRANT SMALL CRAFT ADVISORIES ON TUES AFTERNOON. CLARENCE STRAIT MAY ALSO SEE SMALL CRAFT WINDS DUE TO THE FUNNELING BY TERRAIN OF THE PRE- FRONTAL SE WINDS TUES AFTERNOON AND EVENING. OTHER AREAS WILL SEE 20 KT OR LESS WITH THE STRONGEST WINDS IN THE EXTREME SOUTH AND ALONG THE SOUTHERN OUTER COAST. I AM NOT EXPECTING ANY STRONG WIND HEADLINES TO BE NEEDED AS 850 MB WINDS WITH THIS SYSTEM ARE NOT VERY IMPRESSIVE. WINDS WILL DIMINISH LATE TUES NIGHT AS THE PARENT LOW WEAKENS IN THE EASTERN GULF AND THE FRONT PUSHES THROUGH INTO BRITISH COLUMBIA. BEHIND IT WEST TO SOUTHWEST FLOW SETS UP OVER THE PANHANDLE AND GULF. THIS GENERALLY WILL KEEP THE CHANCE OF SHOWERS IN THE FORECAST INTO LATE WEEK. PARTICULARLY WHEN A WEAK WAVE MOVES EAST INTO THE NORTHERN PANHANDLE ON THURS ENHANCING THE SHOWERS AS IT COMES. INTO THE WEEKEND, LONG RANGE MODELS DIVERGE A BIT AS THE THEY DEPICT A BROAD RIDGE TO SET UP OVER THE GULF BUT THE ECMWF ALSO DIGS A STRONG UPPER TROUGH SOUTH OVER THE PANHANDLE OVER THE WEEKEND. THE GFS IS MUCH WEAKER AND SLOWER WITH IT. AS A RESULT THE ECMWF IS JUST A BIT WETTER FOR THE WEEKEND THEN THE GFS IS DEPICTING. HOWEVER, THE ECMWF IS NOT VERY CONSISTENT WITH THIS FEATURES SO FAVORED THE MORE CONSISTENT GFS AND HPC THROUGH THE WEEKEND. FORECAST CONFIDENCE IS ABOVE AVERAGE THROUGH MID TO LATE WEEK THEN DROPS TO AVERAGE FOR THE WEEKEND. .AJK WATCHES/WARNINGS/ADVISORIES... PUBLIC...NONE. MARINE...SMALL CRAFT ADVISORY FOR PKZ012. && $$ HANNON/EAL ______________________________________________________________________ PAJK - Reference: ['circulation centers visible on ir and viirs nighttime visible'] 212 FXAK67 PAJK 211453 AFDAJK SOUTHEAST ALASKA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JUNEAU AK 553 AM AKST WED NOV 21 2012 .SHORT TERM...SOMEWHAT COMPLICATED PATTERN IN THE GULF AND NORTHEAST PACIFIC THIS MORNING. THERE ARE AROUND 4 SEPARATE CIRCULATION CENTERS VISIBLE ON IR AND VIIRS NIGHTTIME VISIBLE IMAGES. THE STRONGEST IS WEST OF DIXON ENTRANCE CURRENTLY AND IS SLOWLY WEAKENING AS IT REMAINS NEARLY STATIONARY. A SECOND LOW IS JUST SE OF KODIAK ISLAND, A THIRD IS AROUND 50N 140W, AND THE FOURTH IS A VERY WEAK ONE OVER HAIDA GWAII. THEY ARE RESPONSIBLE FOR THE SHOWERS THAT ARE OVER THE SOUTHERN INNER CHANNELS AT THE MOMENT. KETCHIKAN AND ANNETTE HAVE BEEN REPORTING RAIN MOST OF THE MORNING AND THE RADAR SHOWS SOME SHOWERS AROUND SOUTHERN BARANOF ISLAND AS WELL. PRECIP AMOUNTS HAVE BEEN LIGHT FOR THE MOST PART. THESE FEATURES WILL CONTINUE TO WEAKEN OVER THE NEXT 12 TO 18 HOURS AS A DEVELOPING LOW IN THE NORTH CENTRAL GULF BEGINS TO SPREAD ITS INFLUENCE INTO THE GULF. ALSO AFFECTING THE AREA IS A STRONG HIGH PRESSURE SYSTEM IN THE YUKON THAT ALONG WITH THE LOWS IN THE GULF ARE CAUSING STRONG COLD OUTFLOW WINDS OVER MOST OF THE NORTHERN PANHANDLE. HAINES, SKAGWAY AND JUNEAU ARE STILL UNDER STRONG WIND HEADLINES DUE TO THIS FOR THE MORNING AND MOST NORTHERN INNER CHANNELS HAVE EITHER GALE WARNINGS OR SMALL CRAFT ADVISORIES. THE WINDS IN JUNEAU ARE MAINLY DUE TO A MODERATE TAKU WIND EVENT THAT PEAKED LAST NIGHT WITH GUSTS TO 45 TO 50 KT AT SOUTH DOUGLAS AND THE FEDERAL BUILDING. THESE WINDS SHOULD DIMINISH THROUGH THE DAY AS THE LOWS IN THE GULF WEAKEN AWAY AND CROSS BARRIER FLOW DIMINISHES. THINGS START TO GET INTERESTING LATE TONIGHT AS WE START TO GET MORE INFLUENCE FROM THE DEVELOPING STRONG STORM IN THE NORTHERN PACIFIC. BY 12Z THURS THE LOW WILL HAVE DROPPED TO 970 MB AND BE AROUND 50N 145W. THE ASSOCIATED FRONT WILL BE MOVING NORTH THROUGH THE NIGHT BUT WILL STILL BE SOUTH OF THE AREA BY LATE TONIGHT. THE WINDS HOWEVER WILL NOT. I AM EXPECTING E TO SE WIND UP TO STORM FORCE FOR THE SOUTHERN OUTER MARINE ZONE BY LATE TONIGHT AND GALES FOR THE REST OF THE SOUTHERN INNER CHANNELS AND OUTER MARINE ZONES. ON LAND, GUSTS COULD BE REACHING INTO THE 50 TO 60 MPH RANGE BY LATE TONIGHT. AS FOR PRECIP NOT MUCH IS EXPECTED YET. THE MAIN RAIN BANDS WILL STILL BE SOUTH OF THE AREA BY LATE TONIGHT BUT SOME SHOWERS COULD STILL REMAIN OVER THE PANHANDLE FROM THE NOW DISSIPATED LOWS THAT WERE OVER THE AREA TODAY AS WELL AS FROM ANY WEAKER PRE-FRONTAL BANDS. MOST OF THE PRECIP WILL BE OVER THE SOUTH AS THE NORTHERLY OUTFLOW AND DRY COLD AIR OVER THE NORTH WILL INHIBIT THE PRECIP FROM MAKING IT INTO THE NORTHERN HALF OF THE PANHANDLE. AS FOR TYPE BARANOF ISLAND, PRINCE OF WALES, AND AREAS SOUTH OF WRANGELL WILL BE WARM ENOUGH FOR RAIN WITH MAYBE SOME SNOW MIXED IN AT TIMES. NORTH OF THESE AREAS WILL SEE SNOW BUT ANY ACCUMULATIONS WILL BE LIGHT IF PRECIP FALLS AT ALL. SHORT RANGE MODELS WERE IN DECENT AGREEMENT FOR THE PERIOD. NAM SEEMED TO HAVE THE BEST AGREEMENT WITH THE VARIOUS FEATURES THAT WERE PRESENT OUT IN THE GULF THIS MORNING SO MAIN GUIDANCE WAS IN THAT DIRECTION. GFS WAS A CLOSE SECOND, WHILE THE EC LAGGED BEHIND DUE TO IT REPRESENTING THE FEATURES AS A LITTLE TOO WEAK. FORECAST CONFIDENCE IS ABOUT AVERAGE. && .LONG TERM...A POWERFUL LOW IS EXPECTED DEVELOP AND MOVE TO THE SOUTHERN GULF ON THURSDAY. THE WEATHER FRONT AND VERY STRONG WINDS WILL MOVE ACROSS THE SOUTHEAST GULF WATERS EARLY THURSDAY MORNING AND THE SOUTHERN HALF OF THE PANHANDLE DURING THE DAY. LOOKING FOR 60+ KT WINDS FOR PORTIONS OF THE GULF... AND POTENTIALLY GUSTS OF 6O TO 80 MPH OR MORE TO IMPACT THE PRINCE OF WALES ISLAND NORTH TO SOUTHERN BARANOF ISLAND. THE LOW POSITION AND STRENGTH OF THE LOW IS LEADING TO STRONG CROSS BARRIER FLOW IN THE JUNEAU AREA THAT IS FAVORABLE TO TAKU LIKE WINDS FOR THURSDAY IN THE DOWNTOWN JUNEAU AREA AND DOUGLAS. AS THE FRONT MOVES NORTH ON THURSDAY THE PRECIPITATION WILL HAVE TO OVERCOME DOWNSLOPE CONDITIONS IN THE CENTRAL AND NORTHERN PANHANDLE. ANOTHER ISSUE IS HOW MUCH WARMING WILL BE GOING ON AND IMPACTING THE PRECIPITATION TYPE. THE SOUTHERN PORTION OF THE PANHANDLE WILL NEED TO WATCH FOR FRIDAY AS WELL AS THE LOW APPROACHES PRINCE OF WALES ISLAND ANOTHER BATCH OF GUSTY WINDS WILL LIKELY AFFECT THEM THE AS WELL. AFTER THAT THE LOW WEAKENS MORE AND SLIDES EAST LEAVING RESIDUAL SHOWERS THROUGH THE WEEKEND AND ANOTHER SYSTEM TRYING TO SPREAD EARLY NEXT WEEK. CONFIDENCE IS FAIRLY GOOD TO ABOUT SATURDAY AND THEN FALLS OFF TO AVERAGE OR SLIGHTLY LESS FOR EARLY NEXT WEEK. .AJK WATCHES/WARNINGS/ADVISORIES... PUBLIC...HIGH WIND WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR AKZ023-026>028. STRONG WIND UNTIL 9 AM AKST THIS MORNING FOR AKZ025. HIGH WIND WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR AKZ025. STRONG WIND LATE TONIGHT FOR AKZ029. STRONG WIND UNTIL NOON AKST TODAY FOR AKZ018-019. MARINE...STORM WARNING FOR PKZ012-041. GALE WARNING FOR PKZ011-013-021-022-031-033-035-036-042-043. SMALL CRAFT ADVISORY FOR PKZ032-034-051-052. && $$ EAL/BEZENEK ______________________________________________________________________ --- Site: PGUM --- --- Site: PHFO --- PHFO - Reference: ['with the help of polar orbiting satellites...filling the gap of '] 443 FXHW60 PHFO 231346 AFDHFO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 330 AM HST FRI MAR 23 2012 .SYNOPSIS... STRONG HIGH PRESSURE LOCATED FAR NORTH OF THE ISLANDS WILL CONTINUE TO GENERATE STRONG AND GUSTY TRADES INTO THE WEEKEND. THE REMNANTS OF AN OLD FRONT AND A UPPER LEVEL DISTURBANCE WILL RESULT IN A WET TRADE WIND REGIME MAINLY TONIGHT AND INTO SATURDAY. A RETURN TO A MORE TYPICAL TRADE WIND REGIME WILL SLIDE IN BY MONDAY. WITH THE AID OF MID LEVEL RIDGING...THE TRADE SHOWERS WILL RESULT IN LIGHT RAINFALL AMOUNTS. THESE SHOWERS WILL BE CONFINED TO THE WINDWARD AND MOUNTAIN AREAS...AND BE MOST ACTIVE DURING THE NIGHTS AND MORNINGS. && .DISCUSSION... WITH THE HELP OF POLAR ORBITING SATELLITES...FILLING THE GAP OF THE GOES WEST...HINT ON THE SOUTHWARD MOVEMENT OF THE FRONTAL BOUNDARY HAS SLOWED DOWN. THE SHOWERS WE HAVE EXPERIENCED THUS FAR ARE THAT OF THE TRADE WIND FLOW. THIS INCLUDE WHAT THE RADAR IS CURRENTLY DETECTING...A BATCH OF LOOSE SCATTERED SHOWERS PASSING THROUGH THE WINDWARD WATERS OF MOLOKAI AND OAHU...HEADING IN THE DIRECTION OF KAUAI. THE 2 AM RAOB RUNS FROM LIHUE AND HILO SHOWED THE AIR MASS RECOVERED FROM 24 HOURS AGO WHERE THE MORE ROBUST SHOWERS SHOWED UP. THIS MORNING SOUNDINGS SHOWED THE AIR MASS BEING DRIER WITH AN INVERSION AT 10 THOUSAND FEET. THEREFORE...THE WIDESPREAD HEAVY SHOWERS FORECAST THIS MORNING HAS BEEN REMOVED...BUT REMAINS FOR THIS AFTERNOON. WE STILL BELIEVE THE BULK OF THE HEAVY WEATHER TO OCCUR TONIGHT WHERE THE SIGNIFICANT COOLING OF THE MID LAYERS OCCURS AND THE REMNANTS OF THE FRONT BEING CLOSER TO THE ISLANDS. WE WILL CONTINUE TO MONITOR AND MAKE ADJUSTMENTS TO THE FORECAST PACKAGE AS NEEDED. FRIENDLIER SKIES ARE STILL ON TAP STARTING THIS SUNDAY AND LASTING THROUGH AT LEAST WEDNESDAY. WITH THE HELP OF RIDGING ALOFT...THE TRADE SHOWERS WILL BE ON THE LIGHT SIDE. THE FREQUENCY OF SHOWERS WILL PICKUP AT NIGHT AND DROP OFF TO ISOLATED BY MID MORNING. THE STRENGTH OF THE TRADE WINDS WILL START TO EASE OFF WITH MODERATE TO LOCALLY STRONG TRADES BY SUNDAY AND MODERATE TRADES BY TUESDAY. THIS IS IN LIGHT OF THE 1035 MILLIBAR /MB/ HIGH PRESSURE CELL NORTH OF THE ISLANDS NEAR 37N158W...WEAKENING TO A 1024 MB HIGH NEAR 30N167W BY TUESDAY. THE GEOSTATIONARY SATELLITE /GOES-15/ THAT PROVIDES IMAGERY OVER THE PACIFIC...INCLUDING THE CENTRAL PACIFIC AND HAWAIIAN ISLANDS...HAS SUFFERED A MALFUNCTION...AND IMAGERY IS UNAVAILABLE. ESTIMATED TIME OF RESTORATION IS NO EARLIER THAN 6 AM FRIDAY...MARCH 23. PLEASE SEE THE LATEST PUBLIC INFORMATION STATEMENT FOR MORE INFORMATION AND UPDATES /HFOPNSHFO/. && .AVIATION... WE WILL CONTINUE TO CLOSELY MONITOR THE BOUNDARY NORTH OF THE ISLANDS. LOOSE SHOWER BEARING CLOUDS AHEAD OF THE BOUNDARY CONTAINS BRIEF MVFR CONDITIONS THAT WILL AFFECT PRIMARILY THE WINDWARD AND MOUNTAIN AREAS...AND EXPOSED TERMINAL STATIONS SUCH AS HILO AND LIHUE. SOME OF THESE SHOWERS WILL BE CARRIED DOWNWIND INTO THE LEEWARD DISTRICTS. AIRMET TANGO WILL REMAIN IN EFFECT FOR THE LOW LEVEL TURBULENCE BELOW 10 THOUSAND FEET SOUTH THROUGH WEST OF MOUNTAINS OF ALL ISLANDS...AND WILL LIKELY CONTINUE INTO THE WEEKEND. WE WILL CONSIDER OTHER AIRMETS SHOULD THE BOUNDARY BECOMES A FACTOR. && .MARINE... A SMALL CRAFT ADVISORY IS IN EFFECT FOR ALL HAWAIIAN WATERS THROUGH SATURDAY DUE TO STRONG TRADE WINDS AND COMBINED SEAS FROM THE EAST WIND SWELL AND A NORTH SWELL. A HIGH SURF ADVISORY IS ALSO IN EFFECT FOR THE EAST FACING SHORES OF MOST OF THE ISLANDS EXCEPT LANAI AND NIIHAU UNTIL 6 PM HST SATURDAY. THE NORTH SWELL HAS PEAKED AND WILL BE FADING SLOWLY THROUGH THE WEEKEND. && .HFO WATCHES/WARNINGS/ADVISORIES... HIGH SURF ADVISORY UNTIL 6 PM HST SATURDAY FOR THE EAST FACING SHORES OF ALL ISLANDS EXCEPT LANAI AND NIIHAU. SMALL CRAFT ADVISORY UNTIL 6 PM HST SATURDAY FOR ALL HAWAIIAN WATERS. && $$ LAU ______________________________________________________________________ PHFO - Reference: ['moisture associated with this next band is shallower. poes amsu/ssmi '] 261 FXHW60 PHFO 250219 AFDHFO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 400 PM HST SAT MAR 24 2012 .SYNOPSIS... STRONG HIGH PRESSURE FAR NORTH OF THE STATE WILL WEAKEN SLIGHTLY TONIGHT AND SUNDAY...ALLOWING TRADE WINDS TO DROP OFF TO MORE MODERATE LEVELS. AN UPPER LEVEL TROUGH INTERACTING WITH MOISTURE FROM AN OLD FRONT WILL BRING UNSETTLED WEATHER TO THE ISLANDS...WITH LOCALLY HEAVY SHOWERS POSSIBLE AND A SLIGHT CHANCE OF THUNDERSTORMS. THE ATMOSPHERE WILL BEGIN TO STABILIZE ON MONDAY...AND DRIER TRADE WIND WEATHER IS EXPECTED TO RETURN TUESDAY AND WEDNESDAY. && .DISCUSSION... WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH OVER THE STATE... WITH ANOTHER SHORTWAVE NORTH OF THE ISLANDS DIGGING SOUTHWARD. AT THE SURFACE...HIGH PRESSURE IS LOCATED FAR NORTH NORTHEAST OF THE STATE. 00Z SOUNDINGS FROM HILO AND LIHUE SHOW AN UNSTABLE AIRMASS ACROSS THE STATE...WITH 500MB TEMPERATURES -11C/-13C RESPECTIVELY. A VERY WEAK SUBSIDENCE INVERSION IS NOTED ON THE LIHUE SOUNDING NEAR 8000 FT...BUT THERE IS NONE IN THE HILO SOUNDING. PRECIPITABLE WATERS RANGE FROM 1 INCH AT LIHUE TO OVER 1.4 INCHES AT HILO. IN THE NEAR TERM...A NUMBER OF CLOUD BANDS ARE APPARENT NEAR THE ISLANDS. KAUAI IS LOCATED BETWEEN SHOWER BANDS TO THE NORTH AND SOUTH. A LARGER BAND OF CLOUDS IS LOCATED NEAR MAUI COUNTY AND THE BIG ISLAND...AND EXTENDS WELL UPSTREAM TO THE EAST SOUTHEAST FROM THE BIG ISLAND. THIS BAND IS ALREADY SPREADING TO OAHU...AND ACCOUNTS FOR THE INCREASE IN SHOWERS WE HAVE SEEN THIS AFTERNOON. WHILE THE 00Z KAUAI SOUNDING IS INITIALLY DRY...MOISTURE WILL INCREASE TONIGHT AS THE CLOUD BANDS FILL IN AND SPREAD WEST. POPS WILL BE CATEGORICAL ACROSS WINDWARD/MAUKA SECTIONS TONIGHT. WITH THE DEEP MOISTURE AND UNSTABLE AIRMASS...HEAVY RAIN IS POSSIBLE. WHILE THE INSTABILITY IS NARROW AND SPREAD THROUGH THE COLUMN...THERE IS STILL A CONCERN FOR THUNDER AND WILL KEEP A MENTION OF SLIGHT CHANCE FOR TONIGHT. ON THE BIG ISLAND...RANGERS ON MAUNA KEA REPORT SNOW BEGINNING TO ACCUMULATE ON SUMMIT ROADS. WEB CAMS SHOW OCCASIONAL BURSTS OF SNOW...BUT ALSO PERIODS OF LIQUID PRECIPITATION. TEMPERATURES AT ALL OBSERVATION SITES ON MAUNA KEA ARE BELOW FREEZING...GENERALLY 29-31F. DEEPER SHOWERS WILL TAP INTO COLDER AIR AND ALLOW FOR SUFFICIENT ICE NUCLEATION FOR SNOW...WHILE SHALLOWER SHOWERS WILL REMAIN LIQUID...LEADING TO FREEZING RAIN/FREEZING DRIZZLE. THE WINTER WEATHER ADVISORY ISSUED EARLIER THIS AFTERNOON STILL LOOKS GOOD...AND COVERS BOTH SNOW AND FREEZING PRECIPITATION. THE ADVISORY RUNS THROUGH SUNDAY MORNING. THE DEEPER MOISTURE ASSOCIATED WITH THIS FRONTAL REMNANT WILL DIMINISH ON SUNDAY. HOWEVER...AFTER THE BRIEF RESPITE ANOTHER REMNANT BAND WILL MOVE ACROSS THE ISLANDS SUNDAY NIGHT/MONDAY. MOISTURE ASSOCIATED WITH THIS NEXT BAND IS SHALLOWER. POES AMSU/SSMI TOTAL PRECIPITABLE WATER IMAGERY SHOWS PW VALUES ARE MUCH LOWER THAN THE CURRENT FRONTAL BAND. WHILE MOISTURE WILL NOT BE AS DEEP...THE AIRMASS WILL REMAIN UNSTABLE. THE SECOND SHORTWAVE TROUGH NOTED ABOVE WILL DIVE SOUTHWARD...REINFORCING THE MID-LEVEL COLD POOL OVER THE STATE. WHEREAS 500MB TEMPERATURES ARE -11C TO -13C NOW...THE 18Z GFS SHOWS THEM DROPPING TO NEAR -15C SUNDAY NIGHT. THE CURRENT FORECAST DOES NOT HAVE THUNDER MENTIONED BEYOND TONIGHT...BUT THIS MAY NEED TO BE REEVALUATED DEPENDING ON HOW THE SITUATION EVOLVES TONIGHT. THE UPPER TROUGH BEGINS TO MOVE EAST ON MONDAY...WITH MID-LEVEL HEIGHTS REBUILDING AND TEMPERATURES WARMING. FORECAST SOUNDINGS SHOW THE AIRMASS STABILIZING...WITH A TYPICAL SUBSIDENCE INVERSION REDEVELOPING. MODERATE TRADE WINDS WILL CONTINUE THROUGH THE WEEK... KEEPING SHOWERS FOCUSED ACROSS WINDWARD AND MAUKA AREAS. WITH DRIER LOW-LEVEL AIR...RAINFALL CHANCES WILL RETURN TO NEAR NORMAL CLIMATOLOGICAL VALUES. && .AVIATION... VFR CONDITIONS PREVAIL AT ALL TAF SITES WITH THE EXCEPTION OF PHTO WHERE OCCASIONAL MVFR CONDITIONS ARE OCCURING. MVFR CONDITIONS ARE LIKELY OCCURING ALONG WINDWARD SLOPES AND OVER MOUNTAINOUS TERRAIN WITH SOME LOCAL IFR CONDITIONS POSSIBLE. THESE CONDITIONS WILL CONTINUE THROUGH TONIGHT. AIRMET TANGO REMAINS UP FOR LOW LEVEL TURBULENCE S AND W OF MOUNTAINS OF ALL ISLANDS. THESE CONDITIONS WILL CONTINUE THROUGH TONIGHT AS WELL. && .MARINE... A SMALL CRAFT ADVISORY IS IN EFFECT THROUGH TONIGHT FOR ALL HAWAIIAN COASTAL WATERS FOR A COMBINATION OF THE BREEZY TRADE WINDS AND COMBINED SEAS FROM THE WIND WAVES...NORTHERLY AND SOUTHERLY SWELLS. BOTH THE TRADE WINDS AND SWELLS ARE EXPECTED TO SUBSIDE BY SUNDAY TO DROP MOST OF THE ZONES OUT OF THE ADVISORY...LIKELY LEAVING ONLY THE TYPICAL WINDY ZONES AROUND THE BIG ISLAND AND MAUI COUNTY THROUGH THE DAY SUNDAY. TRADE SWELL WILL BACK DOWN OVER THE NEXT FEW DAYS. WAVEWATCH III GUIDANCE SHOWS THE SWELL REMAINING ABOVE 10 FEET INTO SUNDAY AFTERNOON...AND THIS LOOKS REASONABLE WITH CURRENT COMBINED SEAS AT MOKAPU AROUND 12 FEET. THEREFORE THE HIGH SURF ADVISORY HAS BEEN EXTENDED THROUGH 4PM SUNDAY. ELSEWHERE MAINLY SMALL SURF IS EXPECTED. NORTH SHORE WILL PULL IN SOME HEAD HIGH PLUS NORTHWEST SWELL DURING THE SECOND HALF OF THE WEEK. THE CHEST-SHOULDER HIGH BUMP ALONG THE SOUTH FACERS WILL DROP OVER THE NEXT FEW DAYS. A STRONGER SHOT OF SOUTHERN HEMI ENERGY WILL FILL IN DURING THE SECOND HALF OF THE WEEK WITH HEAD HIGH AND OCCASIONAL PLUS SURF EXPECTED. && .HFO WATCHES/WARNINGS/ADVISORIES... HIGH SURF ADVISORY UNTIL 4 PM HST SUNDAY FOR THE EAST FACING SHORES OF ALL ISLANDS EXCEPT LANAI AND NIIHAU. WINTER WEATHER ADVISORY UNTIL NOON HST SUNDAY FOR BIG ISLAND SUMMITS. SMALL CRAFT ADVISORY UNTIL 6 AM HST SUNDAY FOR ALL HAWAIIAN WATERS. && $$ PUBLIC...BRAVENDER AVIATION...BURKE MARINE...FOSTER/DEJESUS ______________________________________________________________________ PHFO - Reference: ['lihue to 1.0 inches at hilo. early afternoon poes amsu/ssmi total '] 905 FXHW60 PHFO 010211 AFDHFO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 400 PM HST SAT MAR 31 2012 .SYNOPSIS... GUSTY TRADE WINDS WILL CONTINUE THIS EVENING...AND WILL BE STRONGEST ACROSS THE EASTERN HALF OF THE STATE. THE TRADES WILL EASE FURTHER ON SUNDAY...AND TURN TO THE EAST-SOUTHEAST EARLY NEXT WEEK...AS THE HIGH NORTHEAST OF THE STATE QUICKLY MOVES AWAY. A DRY AND STABLE AIRMASS WILL LIMIT THE EXTENT OF TRADE SHOWERS TONIGHT. MOISTURE AND INSTABILITY WILL GRADUALLY INCREASE EARLY NEXT WEEK. HEAVY RAIN IS POSSIBLE DURING THE SECOND HALF OF THE WEEK AS A TROUGH DEVELOPS WEST OF THE STATE. && .DISCUSSION... WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL RIDGE OVER THE STATE... BETWEEN AN UPPER LOW TO OUR SOUTHEAST AND A SHARP TROUGH DIGGING TO THE NORTHWEST. AT THE SURFACE...HIGH PRESSURE IS LOCATED FAR TO THE NORTHEAST. A DISSIPATING FRONT IS LOCATED BETWEEN US AND THE HIGH... WHILE A STRONGER FRONT AND LOW IS LOCATED FAR TO THE NORTHWEST. THE 00Z SOUNDINGS SHOW INVERSION HEIGHTS RANGING FROM 5KFT AT LIHUE TO 7KFT AT HILO. PRECIPITABLE WATERS ALSO RANGE FROM 0.8 INCHES AT LIHUE TO 1.0 INCHES AT HILO. EARLY AFTERNOON POES AMSU/SSMI TOTAL PRECIPITABLE WATER IMAGERY SHOWS AN AREA OF HIGHER MOISTURE EXTENDING SOUTHEAST OF THE BIG ISLAND...WITH PW VALUES AROUND 1.4 INCHES. THE SURFACE HIGH FAR NORTHEAST OF THE STATE WILL CONTINUE TO MOVE QUICKLY EAST TONIGHT. THE PRESSURE GRADIENT ACROSS THE ISLANDS WILL RAPIDLY WEAKEN FROM WEST TO EAST OVER THE NEXT DAY. 24 HOUR PRESSURE DIFFERENCES HAVE SHOWN AN INCREASING DOWNWARD TREND TODAY. WINDS AT AIRPORTS AND RAWS SITES ACROSS MAUI COUNTY ARE STILL JUST BELOW ADVISORY CRITERIA...WITH SUSTAINED WINDS IN THE 20 MPH RANGE AND WIND GUSTS AROUND 40 MPH. ELSEWHERE...WINDS REMAIN GUSTY BUT ARE NOT AS STRONG AS EARLIER IN THE DAY. THIS IS IN LINE WITH THE HIGH RESOLUTION WRF ARW/NMM RUNS FROM 12Z...WHICH SHOW THE GRADIENT DIMINISHING FROM THE WEST AS THE HIGH DEPARTS. THE WINDS ARE EXPECTED TO DROP OFF QUICKLY THROUGH TONIGHT AND SUNDAY. WHILE WINDS AT LOWER ELEVATIONS ACROSS MAUI COUNTY ARE HOVERING JUST BELOW ADVISORY LEVELS...WINDS AT MEES OBSERVATORY ON HALEAKALA HAVE REMAINED ABOVE 40 MPH THROUGH THE AFTERNOON. THE 00Z SOUNDING FROM LIHUE STILL SHOWED A SECOND INVERSION NEAR 700MB...OR JUST ABOVE SUMMIT LEVEL. THIS INVERSION MAY BE HELPING TO COMPRESS THE AIRMASS AND ACCELERATE IT ACROSS THE SUMMIT...ENHANCING THE WINDS. ONLY THE 00Z WRF FROM UH PICKED UP ON THE STRONGER WINDS HERE...AND SHOWS THEM LINGERING INTO THE EVENING BEFORE DROPPING OFF QUICKLY. THE WIND ADVISORY REMAINS IN EFFECT THROUGH MIDNIGHT TONIGHT. WINDS HAVE ALREADY STARTED TO DIMINISH...AND WILL CONTINUE TO LOWER THROUGH THE EVENING. A WEAKENING STATIONARY FRONT IS LOCATED OVER THE OFFSHORE WATERS NORTHEAST OF THE STATE. THE BAND OF CLOUDS AND MOISTURE ASSOCIATED WITH IT WILL NOT REACH US THOUGH...AS THE STEERING FLOW TURNS MORE SOUTHEASTERLY AND THE FRONT DISSIPATES. THE AREA OF MOISTURE NEAR THE BIG ISLAND WILL SPREAD TO MAUI COUNTY TONIGHT...HELPING TO ENHANCE SHOWERS ACROSS EASTERN SECTIONS. THE AIRMASS REMAINS STABLE THOUGH WITH A SOLID INVERSION IN PLACE UNDER THE UPPER LEVEL RIDGE. THEREFORE SHOWERS MAY INCREASE SOMEWHAT IN COVERAGE BUT RAINFALL AMOUNTS WILL STILL BE LIMITED. WINDS WILL DROP OFF FURTHER SUNDAY/SUNDAY NIGHT AS THE HIGH MOVES AWAY AND THE GRADIENT WEAKENS. WINDS WILL ALSO TURN MORE TOWARD A MORE SOUTHEASTERLY DIRECTION...WHICH WILL ALLOW FOR MORE LAND AND SEA BREEZES ACROSS THE SMALLER ISLANDS DUE TO THE BLOCKED LOW-LEVEL FLOW. TO START THE NEW WEEK...THE GFS AND ECMWF ARE SIMILAR IN THEIR HANDLING OF THE TROUGH DIGGING FROM THE NORTHWEST. THIS TROUGH IS EXPECTED TO WEAKEN AS IT APPROACHES THE STATE...ALTHOUGH HEIGHTS WILL FALL AND THE UPPER LEVEL FLOW WILL TURN CYCLONIC OVER US. THE SURFACE FRONT ASSOCIATED WITH THIS TROUGH IS EXPECTED TO STALL AND DISSIPATE NORTHWEST OF THE AREA. ANOTHER SHORTWAVE WILL DIG DOWN THE BACKSIDE OF THE FIRST TROUGH...DEVELOPING INTO A CUTOFF LOW WEST OF THE STATE. THIS IS WHERE THE ECMWF AND GFS SOLUTIONS DIVERGE...WITH THE GFS DEVELOPING A STRONGER SYSTEM MUCH FARTHER EAST. THE PREFERENCE HAS BEEN TOWARD THE LESS AGGRESSIVE ECMWF SOLUTION...AND THE CURRENT FORECAST CONTINUES TO REFLECT THIS IDEA. THIS FEATURES A SURFACE TROUGH WELL WEST OF THE STATE...AND A GENERAL EAST-SOUTHEAST FLOW ACROSS THE ISLANDS. IT IS WORTH NOTING THAT THE GFS HAS BEEN CONSISTENTLY STRONGER AND FARTHER EAST WITH THE SYSTEM...EVEN DEVELOPING A WEAK SURFACE LOW JUST WEST OF THE OFFSHORE WATERS. THIS SOLUTION WOULD PULL MORE MOISTURE ACROSS THE AREA...AND WOULD MEAN MORE WIDESPREAD/HEAVIER SHOWERS FOR MID-WEEK. && .MARINE... THE WAIMEA BAY BUOY SHOWS THE NORTHWEST SWELL IS NEARING ITS PEAK...WITH COMBINED SEAS AROUND 9 FEET. THIS SWELL WILL KEEP SURF JUST BELOW ADVISORY LEVELS ALONG NORTH AND WEST FACING SHORES. THE MOKAPU BUOY HAS ALSO LEVELED OUT AROUND 11 FEET. THE PERIOD JUMPED TO 12 SECONDS DUE TO WRAP FROM THE NORTHWEST SWELL. THE EASTERLY SWELL IS STILL RUNNING JUST BELOW 8 SECONDS. WAVEWATCH III GUIDANCE SHOWS THE EASTERLY TRADE SWELL NEAR ITS PEAK NOW...THEN BEGINNING TO LOWER TONIGHT AS THE HIGH MOVES EAST AND WINDS DIMINISH. THEREFORE SURF ALONG EAST FACING SHORES IS ALSO EXPECTED TO REMAIN JUST BELOW ADVISORY LEVELS. FOR MARINE ZONES...HAVE ADJUSTED THE SMALL CRAFT ADVISORY CONFIGURATION TO BETTER ACCOUNT FOR THE CHANGING CONDITIONS AS WINDS WEAKEN AND VEER TO THE EAST SOUTHEAST. WINDS HAVE DROPPED BELOW 25 KNOTS ACROSS THE WESTERN HALF OF THE STATE...BUT COMBINED SEAS ARE STILL A HAZARD DUE TO THE NORTHWEST SWELL. WINDS HAVE DECREASED ENOUGH WEST AND SOUTHWEST OF KAUAI AND OAHU FOR COMBINED SEAS TO DECREASE LESS THAN 10 FEET...AND THEY HAVE BEEN DROPPED FROM THE ADVISORY. ADDITIONAL ZONES WILL DROP OUT THIS EVENING... EVENTUALLY LEAVING JUST THE TYPICALLY WINDIER LOCATIONS NEAR THE BIG ISLAND THROUGH TONIGHT. && .AVIATION... AIRMET TANGO IN EFFECT FOR MECHANICAL LEEWARD TURBULENCE SOUTH THROUGH WEST OF ALL ISLANDS DUE TO STRONG TRADE WINDS. THE WINDS ARE EXPECTED TO WEAKEN TONIGHT AND SHOULD ALLOW THE AIRMET TO BE DROPPED OVERNIGHT OR EARLY SUNDAY MORNING. VFR CONDITIONS WILL PREVAIL AT ALL THE TAF SITES. BRIEF MVFR CONDITIONS AND MOUNTAIN OBSCURATIONS MAY OCCUR ALONG WINDWARD SLOPES PARTICULARLY FOR MAUI AND THE BIG ISLAND. && .HFO WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL MIDNIGHT HST TONIGHT FOR HALEAKALA SUMMIT. SMALL CRAFT ADVISORY UNTIL 6 AM HST SUNDAY FOR ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST WATERS. SMALL CRAFT ADVISORY UNTIL MIDNIGHT HST TONIGHT FOR OAHU WINDWARD WATERS-KAIWI CHANNEL-MAUI COUNTY WINDWARD WATERS- PAILOLO CHANNEL-BIG ISLAND WINDWARD WATERS. && $$ DISCUSSION/MARINE...BRAVENDER AVIATION...FOSTER ______________________________________________________________________ PHFO - Reference: ['the polar satellite showing drier air upstream. the current forecast '] 487 FXHW60 PHFO 201953 AFDHFO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 1000 AM HST THU DEC 20 2012 .SYNOPSIS... STRONG HIGH PRESSURE FAR NORTH OF THE STATE WILL WEAKEN AND MOVE SOUTHEAST THIS WEEK. FRESH TO STRONG TRADE WINDS ACROSS THE AREA WILL GRADUALLY WEAKEN ON FRIDAY AND SATURDAY. SHOWERS WILL BE FOCUSED ACROSS WINDWARD AND MAUKA SECTIONS...BUT WILL CONTINUE TO SPREAD ACROSS LEEWARD AREAS AS WELL. SHOWER ACTIVITY IS EXPECTED TO DECREASE DURING THE WEEKEND...THEN INCREASE AGAIN BY EARLY NEXT WEEK. && .DISCUSSION... WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH JUST MOVING SOUTHEAST OF THE BIG ISLAND...WITH AN AMPLIFIED RIDGE WEST OF KAUAI. AT THE SURFACE...A STRONG HIGH IS LOCATED FAR NORTH OF THE STATE... WITH A DISSIPATING LOW FAR TO THE WEST. 12Z SOUNDINGS FROM HILO AND LIHUE SHOW WEAK AND ELEVATED INVERSIONS AROUND 9KFT. MID-LEVELS ARE DRY...SO THE PRECIPITABLE WATERS AROUND 1.2 INCHES ARE PREDOMINATELY FROM THE LOW-LEVEL MOISTURE. OVERNIGHT MIMIC TOTAL PRECIPITABLE WATER IMAGERY SHOWS DRIER AIR WITH PW VALUES DOWN TO 0.8 INCHES WITHIN 100-150 MILES NORTHEAST OF THE ISLANDS. REGIONAL RADARS AND RAIN GAGES CONTINUE TO SHOW ACTIVE SHOWERS ACROSS THE AREA THIS MORNING. RAINFALL AMOUNTS OVER THE PAST 12 HOURS HAVE BEEN OVER 2 INCHES AT A NUMBER OF BIG ISLAND LOCATIONS... WITH AMOUNTS FROM THE SMALLER ISLANDS GENERALLY AN INCH OR LESS. SATELLITE IMAGERY SHOWS THIS BEING THE LAST SHOWERY BAND WITH MORE STABLE CLOUDS UPSTREAM...WHICH FITS WITH THE OLDER PW IMAGERY FROM THE POLAR SATELLITE SHOWING DRIER AIR UPSTREAM. THE CURRENT FORECAST HAS HIGH POPS THIS MORNING...WITH A DECREASING TREND THIS AFTERNOON. OF COURSE THE TRADE WINDS WILL FOCUS THE MOST SHOWERS ACROSS WINDWARD SECTION...BUT WILL BE STRONG AND CONTINUE TO SPREAD SOME RAIN ACROSS LEEWARD AREAS AS WELL. THE SHOWERY CLOUD BAND WILL LINGER LONGEST NEAR MAUI AND THE BIG ISLAND. FOR THE END OF THE WEEK AND THE WEEKEND...THE SURFACE HIGH WILL WEAKEN AND MOVE SOUTHEAST AS A LARGE LOW PRESSURE SYSTEM DEVELOPS FAR NORTHWEST OF THE STATE. WINDS WILL GRADUALLY WEAKEN OVER THE NEXT TWO DAYS...EVENTUALLY TURNING MORE SOUTHEASTERLY OVER THE WEEKEND. DRIER AIR AND MORE STABLE CONDITIONS WILL ALSO SPREAD OVER THE ISLANDS...LEADING TO FEWER SHOWERS WITH LESS RAINFALL THAN WE HAVE SEEN THE PAST FEW DAYS. THE SYSTEM DEVELOPING OVER THE WEEKEND IS EXPECTED TO TRACK EAST WELL NORTH OF THE AREA EARLY NEXT WEEK...BUT MAY BRING A FRONT/SHEAR LINE TO THE ISLANDS. IN PREVIOUS RUNS THE GFS HAS BEEN AN OUTLIER COMPARED TO THE OTHER EXTENDED MODELS...WITH RECENT RUNS TRENDING INTO BETTER AGREEMENT WITH RESPECT TO THE PARENT LOW. SIGNIFICANT DIFFERENCES REMAIN NEAR THE ISLANDS THOUGH. AS EARLY AS FRIDAY NIGHT THE GFS TRIES TO SPIN UP A LOW FAR WEST SOUTHWEST OF THE STATE...IN A CURRENT AREA OF CONVECTION ALONG A SURFACE TROUGH. THE GFS THEN MERGES THIS LOW WITH THE APPROACHING FRONT TO BRING A SURGE OF CONVECTION ACROSS THE STATE FROM THE SOUTHWEST. THE ECMWF HAS A SIMILAR INVERTED TROUGH SOUTHWEST OF THE STATE...BUT DOES NOT DEVELOP IT NEAR AS MUCH...AND CONSEQUENTLY KEEPS THE BULK OF THE PRECIPITATION ASSOCIATED WITH IT AWAY FROM THE STATE. THE GFS SOLUTION IS DISCOUNTED BECAUSE OF GRIDSCALE FEEDBACK PROBLEMS. AS EARLY AS TONIGHT...THE GFS BEGINS TO DEVELOP BULLEYES OF VERY HIGH QPF THROUGH THIS AREA FROM THE GRIDSCALE PRECIPITATION SCHEME RATHER THAN THE CONVECTIVE SCHEME. BECAUSE OF THIS GRIDSCALE CONVECTION... THE GFS DEVELOPS A STRONG MID-LEVEL VORTICITY CENTER AND A SPURIOUS SURFACE LOW THAT PROVIDES THE FOCUS FOR FUTURE CONVECTION. THE GFS THEN MERGES THIS AREA WITH THE NORTH PACIFIC FRONT TO SHIFT THE CONVECTION ACROSS THE ISLANDS. BECAUSE OF THE FEEDBACK PROBLEMS WITH THE GFS...WE WILL CONTINUE TO FOLLOW THE ECMWF SOLUTION FOR THE NEXT SYSTEM. WE SHOULD SEE AN INCREASE IN MOISTURE AND PRECIPITATION FOR MONDAY/TUESDAY...BUT NOT TO THE EXTENT OR DURATION OF THE GFS. AS FOR WINTER WEATHER...RANGERS ON MAUNA KEA REPORTED ICE ON THE ROADS FROM SHOWERS THAT REACH SUMMIT LEVEL OVERNIGHT. CONDITIONS HAVE CLEARED OUT AND ADDITIONAL PRECIPITATION IS NOT EXPECTED AT THAT ELEVATION. SNOW IS POSSIBLE EARLY NEXT WEEK WITH THE NEXT SYSTEM...GENERALLY IN THE MONDAY NIGHT THROUGH WEDNESDAY TIMEFRAME. && .MARINE... AN ASCAT PASS WITH GOOD COVERAGE OVERNIGHT SHOWED WIDESPREAD 25 KNOTS THROUGH MOST COASTAL WATERS...WITH 30 KNOTS THROUGH THE ALENUIHAHA CHANNEL. NEARSHORE BUOYS OVER WINDWARD WATERS OF HILO/MAUI/OAHU ARE ALSO REPORTING SEAS OVER 10 FEET. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR ALL COASTAL WATERS DUE TO FRESH TRADES AND COMBINED SEAS. SIMILARLY...A HIGH SURF ADVISORY REMAINS IN EFFECT FOR EAST FACING SHORES AS THE STRONG TRADES WILL MAINTAIN ELEVATED SURF CONDITIONS. BOTH ADVISORIES ARE IN EFFECT UNTIL FRIDAY MORNING. A LARGE NORTHWEST SWELL ARRIVING FRIDAY NIGHT WILL PEAK NEAR ADVISORY LEVELS ON SATURDAY...THEN SLOWLY DIMINISH THROUGH MONDAY. A SLIGHTLY SMALLER NORTHWEST SWELL WILL ARRIVE CHRISTMAS DAY. A SMALL...OUT OF SEASON SOUTH SWELL WILL ARRIVE SATURDAY AND LINGER INTO SUNDAY NIGHT. && .AVIATION... CLD/SHRA REMAIN FOCUSED ON WINDWARD OAHU AND MAUI COUNTY. AIRMET SIERRA FOR MT OBSC WILL EXPIRE BY 22Z OR SHORTLY THEREAFTER. GUSTY TRADES WILL DIMINISH GRADUALLY OVER THE NEXT 24 HRS. AIRMET TANGO WILL REMAIN POSTED THRU THE PD FOR LLVL LEE TURB. WINDWARD OAHU AND MAUI COUNTY TAF SITES WILL SEE FREQUENT MVFR CONDITIONS THRU THE MORNING HOURS. ELSEWHERE VFR WILL BE THE RULE. CONDITIONS WILL TRANSITION BACK TO A DRIER LESS WINDY PATTERN OVER THE NEXT 24-30 HOURS. && .HFO WATCHES/WARNINGS/ADVISORIES... HIGH SURF ADVISORY UNTIL 9 AM HST FRIDAY FOR EAST FACING SHORES OF KAUAI-OAHU-MOLOKAI-MAUI-BIG ISLAND. SMALL CRAFT ADVISORY UNTIL 9 AM HST FRIDAY ALL COASTAL WATERS. && $$ DISCUSSION/MARINE...BRAVENDER AVIATION...DEJESUS ______________________________________________________________________ PHFO - Reference: ['the older pw imagery from the polar satellite showing drier air '] 124 FXHW60 PHFO 210142 AFDHFO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 400 PM HST THU DEC 20 2012 .SYNOPSIS... STRONG HIGH PRESSURE FAR NORTH OF THE STATE WILL WEAKEN AND MOVE SOUTHEAST THIS WEEK. FRESH TO STRONG TRADE WINDS ACROSS THE AREA WILL GRADUALLY WEAKEN THROUGH SATURDAY. SHOWERS WILL BE FOCUSED MAINLY ACROSS WINDWARD AND MAUKA SECTIONS...BUT WILL CONTINUE TO SPREAD ACROSS LEEWARD AREAS AS WELL. SHOWER ACTIVITY IS EXPECTED TO DECREASE DURING THE WEEKEND...THEN INCREASE AGAIN BY EARLY NEXT WEEK. && .DISCUSSION... WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH SOUTHEAST OF THE BIG ISLAND...WITH AN AMPLIFIED RIDGE WEST OF KAUAI. AT THE SURFACE...A STRONG HIGH IS LOCATED FAR NORTH OF THE STATE...WITH A LOW FAR TO THE WEST. 00Z SOUNDINGS FROM LIHUE AND HILO SHOW THE AIRMASS STABILIZING FROM THE WEST BEHIND THE TROUGH...WITH A STRENGTHENING INVERSION BELOW 6KFT AT LIHUE BUT A LINGERING WEAK AND ELEVATED INVERSION AT HILO. PRECIPITABLE WATERS ALSO RANGE FROM 0.9 INCHES AT LIHUE TO 1.2 INCHES AT HILO. LATE MORNING MIMIC TOTAL PRECIPITABLE WATER IMAGERY SHOWS SIMILAR DRY AIR WITH PW VALUES DOWN TO 0.8 INCHES AND AND NORTHEAST OF THE STATE...WITH JUST A LINGERING BAND OF HIGHER MOISTURE NEAR MAUI AND THE BIG ISLAND. REGIONAL RADARS AND RAIN GAGES CONTINUE TO SHOW ACTIVE SHOWERS FROM OAHU EASTWARD THIS AFTERNOON...WITH THE GREATEST RAINFALL AMOUNTS ON MAUI AND THE BIG ISLAND. SATELLITE IMAGERY SHOWS THIS BEING THE LAST SHOWERY BAND WITH MORE STABLE CLOUDS UPSTREAM...WHICH FITS WITH THE OLDER PW IMAGERY FROM THE POLAR SATELLITE SHOWING DRIER AIR UPSTREAM. HAVE INCREASED RAINFALL CHANCES FOR THIS EVENING INTO THE OVERNIGHT FOR MAINLY WINDWARD MAUI AND THE BIG ISLAND...ALTHOUGH OAHU AND THE REST OF MAUI COUNTY WILL STILL SEE LINGERING SHOWERS INTO THE EARLY EVENING. OF COURSE THE TRADE WINDS WILL FOCUS THE MOST SHOWERS ACROSS WINDWARD SECTION...BUT WILL BE STRONG AND CONTINUE TO SPREAD SOME RAIN ACROSS LEEWARD AREAS AS WELL. FOR THE END OF THE WEEK AND THE WEEKEND...THE SURFACE HIGH WILL WEAKEN AND MOVE SOUTHEAST AS A LARGE LOW PRESSURE SYSTEM DEVELOPS FAR NORTHWEST OF THE STATE. WINDS WILL GRADUALLY WEAKEN OVER THE NEXT TWO DAYS...EVENTUALLY TURNING MORE SOUTHEASTERLY OVER THE WEEKEND. DRIER AIR AND MORE STABLE CONDITIONS WILL ALSO SPREAD OVER THE ISLANDS...LEADING TO FEWER SHOWERS WITH LESS RAINFALL THAN WE HAVE SEEN THE PAST FEW DAYS. THE SYSTEM DEVELOPING OVER THE WEEKEND IS EXPECTED TO TRACK EAST WELL NORTH OF THE AREA EARLY NEXT WEEK...BUT MAY BRING A FRONT/SHEAR LINE TO THE ISLANDS. IN PREVIOUS RUNS THE GFS HAS BEEN AN OUTLIER COMPARED TO THE OTHER EXTENDED MODELS...WITH RECENT RUNS TRENDING INTO BETTER AGREEMENT WITH RESPECT TO THE PARENT LOW. SIGNIFICANT DIFFERENCES REMAIN NEAR THE ISLANDS THOUGH. AS EARLY AS FRIDAY NIGHT THE GFS TRIES TO SPIN UP A LOW FAR WEST SOUTHWEST OF THE STATE...IN A CURRENT AREA OF CONVECTION ALONG A SURFACE TROUGH. THE GFS THEN MERGES THIS LOW WITH THE APPROACHING FRONT TO BRING A SURGE OF CONVECTION ACROSS THE STATE FROM THE SOUTHWEST. THE ECMWF HAS A SIMILAR INVERTED TROUGH SOUTHWEST OF THE STATE...BUT DOES NOT DEVELOP IT NEAR AS MUCH...AND CONSEQUENTLY KEEPS THE BULK OF THE PRECIPITATION ASSOCIATED WITH IT AWAY FROM THE STATE. THE GFS SOLUTION IS DISCOUNTED BECAUSE OF GRIDSCALE FEEDBACK PROBLEMS. AS EARLY AS TONIGHT...THE GFS BEGINS TO DEVELOP BULLEYES OF VERY HIGH QPF THROUGH THIS AREA FROM THE GRIDSCALE PRECIPITATION SCHEME RATHER THAN THE CONVECTIVE SCHEME. BECAUSE OF THIS GRIDSCALE CONVECTION... THE GFS DEVELOPS A STRONG MID-LEVEL VORTICITY CENTER AND A SPURIOUS SURFACE LOW THAT PROVIDES THE FOCUS FOR FUTURE CONVECTION. THE GFS THEN MERGES THIS AREA WITH THE NORTH PACIFIC FRONT TO SHIFT THE CONVECTION ACROSS THE ISLANDS. BECAUSE OF THE FEEDBACK PROBLEMS WITH THE GFS...WE WILL CONTINUE TO FOLLOW THE ECMWF SOLUTION FOR THE NEXT SYSTEM. WE SHOULD SEE AN INCREASE IN MOISTURE AND PRECIPITATION FOR MONDAY/TUESDAY...BUT NOT TO THE EXTENT OR DURATION OF THE GFS. AS FOR WINTER WEATHER...EARLY THIS MORNING RANGERS ON MAUNA KEA REPORTED ICE ON THE ROADS FROM SHOWERS THAT REACHED SUMMIT LEVEL LAST NIGHT. WHILE CONDITIONS HAVE CLEARED OUT SOMEWHAT TODAY...THE NEXT BAND OF MOISTURE PUSHING INTO THE BIG ISLAND MAY BRING SOME SHOWERS TO SUMMIT LEVEL. WITH FREEZING LEVELS OF 12-13KFT AND SURFACE TEMPERATURES AT THE SUMMIT AROUND FREEZING...ANOTHER PERIOD OF LIGHT SNOW OR FREEZING DRIZZLE IS POSSIBLE.. ANOTHER CHANCE FOR SNOW IS POSSIBLE EARLY NEXT WEEK WITH THE NEXT SYSTEM...GENERALLY IN THE MONDAY NIGHT THROUGH WEDNESDAY TIMEFRAME. && .MARINE... AN ASCAT PASS WITH GOOD COVERAGE THIS MORNING SHOWED WIDESPREAD 25 KNOTS THROUGH MOST COASTAL WATERS...WITH 30 KNOTS THROUGH BOTH THE ALENUIHAHA AND KAIWI CHANNELS. NEARSHORE BUOYS OVER WINDWARD WATERS OF HILO/MAUI/OAHU ARE ALSO REPORTING SEAS OF 10-11 FEET. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR ALL COASTAL WATERS DUE TO THE STRONG TRADES AND COMBINED SEAS. SIMILARLY...A HIGH SURF ADVISORY REMAINS IN EFFECT FOR EAST FACING SHORES AS THE STRONG TRADES WILL MAINTAIN ELEVATED SURF CONDITIONS. BOTH ADVISORIES ARE IN EFFECT UNTIL FRIDAY MORNING. A LARGE NORTHWEST SWELL ARRIVING FRIDAY NIGHT WILL PEAK NEAR ADVISORY LEVELS ON SATURDAY...THEN SLOWLY DIMINISH THROUGH MONDAY. A SLIGHTLY SMALLER NORTHWEST SWELL WILL ARRIVE CHRISTMAS DAY. A SMALL...OUT OF SEASON SOUTH SWELL WILL ARRIVE SATURDAY AND LINGER INTO SUNDAY NIGHT. && .AVIATION... CLD/SHRA/BR ARE PERSISTENT ALONG WINDWARD TERRAIN OVER OAHU AND HAWAII/MAUI COUNTIES. STUBBORN MVFR CONDITIONS CONTINUE. BETTER CONDITIONS ARE STILL EXPECTED FOR LATE AFTERNOON ALTHOUGH DID MOVE BACK TO THE EXPIRATION TIME FOR AIRMET SIERRA TO THE 00Z-02Z WINDOW. TRADES REMAIN STRONG WITH WIDESPREAD LEE TURB CONTINUING. TURB ALOFT CONTINUES TO PRODUCE MOD CHOP FOR HIGH LVL TRAFFIC. AIRMET TANGO REMAINS POSTED FOR BOTH AREAS OF TURB. THE HIGH LVL TURB SHOULD EASE CLOSER TO 04Z OR SHORTLY THEREAFTER. THE LLVL TURB PORTION WILL CONTINUE BEYOND 10Z AND INTO FRI. SHRA/BR CONTINUE TO PRODUCE SPOTTY MVFR OBS FOR WINDWARD AND SOME HIGHER ELEVATION TERMINALS. COND SHOULD IMPROVE WITHIN THE NEXT FEW HOURS AS THE AFOREMENTIONED SHRA/RA THIN OUT WITH MAINLY VFR EXPECTED THROUGH THE REMAINDER OF THE TAF PD. && .HFO WATCHES/WARNINGS/ADVISORIES... HIGH SURF ADVISORY UNTIL 9 AM HST FRIDAY FOR EAST FACING SHORES OF KAUAI-OAHU-MOLOKAI-MAUI-BIG ISLAND. SMALL CRAFT ADVISORY UNTIL 9 AM HST FRIDAY ALL COASTAL WATERS. && $$ DISCUSSION/MARINE...BRAVENDER AVIATION...DEJESUS ______________________________________________________________________ --- Site: TJSJ --- --- Site: NSTU ---