Ceilings

21 October 2019 – nighttime detection of fog and outflow boundaries

During the overnight hours of 21 October 2019, we analyze multiple applications of GOES imagery at night. First, we look over the northeast where fog developed.  Here is the GOES-16 nighttime microphysics product: http://rammb.cira.colostate.edu/templates/loop_directory.asp?data_folder=training/visit/loops/21Oct19/fog&loop_speed_ms=60 We observe large areas of fog (dull aqua) or low clouds (aqua) in Pennsylvania, New York, Vermont, New Hampshire and Massachusetts.  Continue Reading

Aviation Weather Ceilings Convection Fog Severe Weather Visibility

Low cloud / fog over snow covered ground on 25 February 2019

During the overnight hours of 25 February 2019, low clouds and fog developed over portions of northwest Kansas, eastern Colorado and southwest Nebraska.  The low cloud and fog developed over a field of snow on the ground from a recent blizzard.  Low cloud and fog on top of snow on the ground can be difficult Continue Reading

Ceilings Fog Visibility

Fog event of 22 May 2018 in the midwest – focus on nighttime microphysics RGB

During the overnight and morning hours of May 22, 2018 there was widespread fog over the upper midwest region centered around Wisconsin.  We’ll start by looking at the familiar fog product (10.3 – 3.9 micron) overlaid with ceiling (top left: hundreds of feet AGL) and visibility (bottom in miles): http://rammb.cira.colostate.edu/templates/loop_directory.asp?data_folder=training/visit/loops/22may18/fog&loop_speed_ms=180 Recall in the fog product, Continue Reading

Aviation Weather Ceilings Fog Visibility

Interesting features along the west coast on 15 August 2017

The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing.  Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized. The following loop is the GOES-16 visible (0.64 micron) band centered along the California / Oregon border on the Continue Reading

Aviation Weather Ceilings Fog Island Effects Orographic Effects Visibility

Gap flow in the Strait of Juan de Fuca

The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing.  Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized. On the morning of 18 July 2017, low-level clouds moved eastward through the Strait of Juan de Fuca.  This Continue Reading

Ceilings Fog Visibility

24 March 2017 fog / low stratus in the West

The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing.  Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized. On the morning of 24 March 2017, there were some interesting fog / low stratus events in the West. Continue Reading

Ceilings Fog GOES R Orographic Effects Visibility

Synthetic Low Cloud / Fog Product for October 10, 2012

Dan Bikos This blog entry will examine the synthetic low cloud / fog product produced by the 4-km NSSL WRF-ARW model.  For detailed information on this product, see: http://rammb.cira.colostate.edu/training/visit/training_sessions/synthetic_imagery_in_forecasting_low_clouds_and_fog/ Let’s examine this product on the Washington and Oregon coastline from October 10, 2012: http://rammb.cira.colostate.edu/templates/loop_directory.asp?data_folder=training/visit/loops/10oct12_west_syn_fog&image_width=1020&image_height=900 Recall that low cloud or fog is depicted as blue in Continue Reading

Aviation Weather Ceilings Fog GOES-R Proving Ground Visibility