Regional and Mesoscale Meteorology Branch

00:00:00:27 – 00:00:25:07
Speaker 1
Welcome to today’s visit Satellite Chat. And the first thing we’ll start off by looking at is a couple of recent, severe weather cases where, we had, goes super rapid scan imagery in effect, and therefore has some pretty nice examples to look at in terms of some, visible imagery. So let’s begin off by May 30th.

00:00:25:09 – 00:00:56:04
Speaker 1
And we’re looking at this storm, right here in north central, central Oklahoma. And I’ll go ahead and leave my cursor right here as to the area to, watch here. And then what I’m going to do is just move my cursor out of the way and advance through this slowly here. So I’m going to advance through slowly and note that, storm there in central Oklahoma.

00:00:56:06 – 00:01:22:03
Speaker 1
And if you watch closely as I step through this here, you’ll see interesting things, not only the the updraft, but if you look very carefully, you can see signs of cyclonic rotation associated with the updraft there. So I’ll just continue to go through that as you, watch that storm. That storm had, a tornado with it for a period of time.

00:01:22:06 – 00:01:42:00
Speaker 1
You can see the flanking line, just to its southwest, and you can see signs of outflow with it as well. Notice that this is goes 15. So, it’s further to the west. We got an oblique oblique angle. We can look back into the, side of the storm here. So, something to keep in mind.

00:01:42:00 – 00:02:08:01
Speaker 1
Is that sr. So, is not currently available anywhere, but we will have higher temporal resolution. Available in the future with, goes are here. So this is, just some something interesting, to look at here when you get these. So now it isn’t available on your website, but it is available, typically on the, the, sera or CIM sites.

00:02:08:01 – 00:02:38:24
Speaker 1
We make these available. If not in real time, then we usually put, blog entries together. So watch, especially The Sims blog for some really nice examples of, this. So imagery. I’m going to go ahead and show a different day now. This is from June 12th, high risk day over. Generally the northern Illinois, eastern Iowa, Indiana region here.

00:02:38:27 – 00:03:07:21
Speaker 1
So as before, I will go ahead and slowly loop through these and, many interesting features to point out as we go through this, the details, that you see on the overshooting tops, the various, cumulus lines and unstable, cloud streets that you see in various areas here. And I’m going to point my cursor to a specific storm here, just as something to watch.

00:03:07:24 – 00:03:35:04
Speaker 1
Watch this storm right here. And generally this region around this overshooting top and just northwest of it. So I’m going to move my cursor out of the way and just watch that as it evolves here. So you see pulsing and then the overshooting tops. And then right about here I go ahead and move my cursor again. You see gravity waves emanating away from that overshooting top.

00:03:35:04 – 00:04:15:02
Speaker 1
So you see, gravity waves moving away from the convection here. Go ahead and advance that along so you can see, if you look around, you’ll see some other gravity waves as well. But but the one I just pointed out was, quite obvious. So I’ll go ahead and run that through, again here so you can see that and once again, just, know remarkable imagery whenever you have, significant events happening like this, particularly when you have a lot of convection around, you can see a whole lot of, details here.

00:04:15:04 – 00:04:28:03
Speaker 1
Okay. What I’m going to do next is turn it over to Ken Prior. Does this talk about, a couple down burst events?

00:04:28:06 – 00:04:49:07
Speaker 2
Okay. Yes. Thanks, Stan. I’ll get started by discussing the, microburst event that occurred on June 10th. Southeast of Denver, actually near Parker, Colorado. And I believe, this particular microburst event, occurred in Elbert.

00:04:49:09 – 00:04:51:12
Speaker 3
County.

00:04:51:14 – 00:05:19:06
Speaker 2
What is very impressive is that this is a very, strong yet isolated event. There was only one wind report in the state of Colorado. During this particular afternoon. And it happened to be an 80 mile per hour wind gust associated with a microburst producing storm. So let’s go ahead here. Take a look at some composite imagery.

00:05:19:06 – 00:05:35:13
Speaker 2
I generated a composite of visible, imagery, Nick’s red reflectivity, and then did an overlay of Goes 15 sounder derived K and microburst wind speed.

00:05:35:13 – 00:05:36:16
Speaker 3
Potential.

00:05:36:18 – 00:06:23:25
Speaker 2
Index values over the image. A like a swing speed potential index is indicated by the MWP I that’s the, abbreviation here. But some important important feature is to point out the actual location of the microburst. Wind gusts over 80mph. And we can see here, in the image over northwestern Elbert County, in a visible inventory, it appears as though there is a larger cluster of weak convective storms, possibly just, late shower activity here over east central Colorado.

00:06:23:28 – 00:07:04:03
Speaker 2
And this microburst occurred on the western edge of this cluster of convective storm activity. Now, the radar overlay, also shows that reflectivity is were quite low, with the parent storm, maximum reflectivity is for only about 25 to 30 CPV. So that’s, the reflectivity on radar was very impressive. And I believe that the actual parent storm, apparent here in the satellite image is actually the storm that I’m pointing to now.

00:07:04:06 – 00:07:41:15
Speaker 2
I believe, due to its placement error, the storm, as we see it in the visible imagery is somewhat to the northeast of the actual location of the downers, but you can see here some brighter, possibly higher cloud tops associated with that storm to the northeast. But again, what is noteworthy was the fact that it’s very strong, like a first related wind gust originated from a parent storm with, very low radar reflectivity, again, below 30, debris.

00:07:41:18 – 00:08:24:16
Speaker 2
And there were no, apparent signatures of radar that you could have associated with the down burst or microburst, such as a bow echo, spearhead, echo. So the activity here at the radar imagery appears. It’s just very late shower activity. Now, to contrast that with what was observed by the echo sounder. And I want to point out that this, image here, particularly the echo sounder, data, is actually from a 20 200ft, which is shortly after the actual, down burst occurrence.

00:08:24:18 – 00:08:56:12
Speaker 2
We did have a sound or processing outage during that particular afternoon between 18 and 2100. So the first available sounder data set was at 20 200ft. But looking here to the southeast of the convective storm complex, at what I consider to be an undisturbed, pre convective environment, we see MWP values that are approaching or in fact exceeding 90.

00:08:56:14 – 00:09:40:08
Speaker 2
I want to stress that these would be very high value. MWP values higher than 80 are very rare. You know, the calculation here to the west of the white line would be for a layer between the 507 hundred millibar level, which is our calculation over the interval. Western United States MWp incorporates temperature lapse rate as well as the difference in dew point depression between the 507 hundred millibar levels, as well as incorporates Kate.

00:09:40:10 – 00:10:27:06
Speaker 2
I do question if the Cape over 6000 here over eastern Colorado is actually representative of. But regardless of WPI values greater than 90 or very impressive for this region. Now let’s compare this to, numerical bottle of data. This would be rapid refresh model derived MWP. Image from the previous hour 2100 C. And what it is indicating here is that Cape values, as calculated by the Rapid Refresh model, are significantly lower up here over eastern Colorado, and in fact are probably 200 or lower.

00:10:27:09 – 00:10:57:16
Speaker 2
So thus the MWP values are lower as well. Regardless, MWP values were over 30. Here over east central, Colorado. Again, this is the same calculation from the 500 to 700 millibar level. And even in this case with Cape values being extremely low, WPI values greater than 30 again would be very impressive or would be significantly higher.

00:10:57:18 – 00:11:28:07
Speaker 2
So regardless, we’re looking at environments that was very favorable for dry microburst. As we can see here in rapid refresh model derived county profile over the Parker area at 21 three we could see cloud base very high. Most likely near the 500 millibar level. And we see a very dry, deep, dry and well-mixed boundary layer beneath the cloud base.

00:11:28:09 – 00:11:59:09
Speaker 2
So thus we can see our, forcing region for very strong downdrafts. That was at least 300 millibars feet, if not greater, and a very dry, surface layer of extending from near the surface up to about the 800 millibar level. So putting all these factors together, we can see here a very favorable environment for dry microburst.

00:11:59:12 – 00:12:38:00
Speaker 2
So let’s move eastward and discuss, a little more of the wind events from the June 12th and 13th. Severe squall line events, over the Midwest and Mid-Atlantic region. I’m going to focus primarily on the wind reports of over the Mid-Atlantic region, which would incorporate rate most of Maryland, and Virginia. The SPC has deemed these events to be low, and Jerry chos basically, these squall line systems barely match the regional criteria.

00:12:38:03 – 00:13:28:26
Speaker 2
So let’s move on here and discuss the warning system system that moved through the Mid-Atlantic region on the morning of June 13th, and I will go ahead and stop the animation. Here we are looking to Goes 35 first wind Speed potential index product. And the imagery here is enhanced water vapor imagery to highlight the coldest cloud tops which early in the morning hours was over west central Pennsylvania and western Maryland and also contrasts out the regions where there was very dry air in the mid troposphere, especially over southern Virginia and the Carolinas, as well as an intrusion of dry air into the western flank of the squall line over western Pennsylvania.

00:13:28:28 – 00:14:00:24
Speaker 2
But even for this time of the morning, which would be, about 6:00. A m eastern time, we see MWP values that are very impressive, especially over the Delmarva Peninsula and lower Chesapeake Bay region, down to the Hampton Roads area. You see very high MWP values over the North Carolina coast, as well as an isolated high index value over south central Virginia.

00:14:00:27 – 00:14:33:03
Speaker 2
Now, as the morning squall line moves eastward up toward the Chesapeake Bay region, we can see that MWP values remain high, over and over the Delmarva Peninsula. And just off the Atlantic coast of Virginia, in excess of 60. If the the morning squall line, some of the highest wind gusts were recorded over the middle and upper Chesapeake Bay region.

00:14:33:06 – 00:15:01:24
Speaker 2
Although there were a number of wind damage reports over north central Beryl and associated with the squall line, one of the highest measured wind gusts was 40 knots, over the upper Chesapeake Bay, and that was recorded by a with dad, we fear Baltimore. So that’s the early morning MWP product image. We go back here in time to the beginning of the animation.

00:15:01:26 – 00:15:40:14
Speaker 2
Here we see values of about 30 to 48, which indicated wind gusts potential at 35 to 49. Not so. Thus the measured down first wind gust of 40 knots associated with the squall line as it moved over the upper Chesapeake Bay was very, well forecasted by the MWP, like during the morning hours. And if we again, if we move outward, it’s time for our first squall line moved eastward eventually over southeastern Pennsylvania, new Jersey, and then off the coast.

00:15:40:16 – 00:15:41:08
Speaker 2
Now let’s.

00:15:41:11 – 00:15:41:18
Speaker 3
Move.

00:15:41:18 – 00:16:22:03
Speaker 2
Forward and take a look at the afternoon squall line. This would have been another squall line that developed over the lower Ohio Valley, and then moved eastward over the Appalachians, and then eventually to the Maryland and Virginia Piedmont. And here in 1850, with the MWP now, visualized with visible imagery, we can see the squall line now moving from the Appalachian Mountains over the Virginia Piedmont during the afternoon hours and we can see if we move back here to 1930.

00:16:22:06 – 00:17:01:15
Speaker 2
That, we could see isolated high MWP values. These would be index values greater than 50 that indicate wind gusts. Potential of 50 knots or greater, both over southern Virginia as well as over the lower Chesapeake Bay. If we move to the next, next two hour period or timestamp at 21 for now, and we can see what appears to be the significant gust front moving out ahead of the main squall line over the, lower Chesapeake Bay and southern Virginia.

00:17:01:17 – 00:17:31:08
Speaker 2
Up near this time, wind gusts over 50 knots were recorded near Jamestown, Virginia, again by a that would you have to believe that would be in this region here, as well as a Lower Cariboo. We, near Annapolis also recorded, wind gust, 52. And we can see now that the higher MWP values have moved eastward over the Atlantic Ocean.

00:17:31:08 – 00:18:30:12
Speaker 2
During this time, the, squall line, which would eventually become known as the second Low Wind derecho, of this day, eventually moved off the Atlantic coast by, 2330 or early evening, eastern time. And we can see, MWP values remained relatively high over the lower Chesapeake Bay as well as over the North Carolina coast. So the, the MWP values were quite effective in indicating relative wind gusts potential here with this, fast moving squall line just on the forward motion of the squall line itself was also likely a factor in some of the, severe, measured severe wind reports, especially over southern Virginia and North Carolina.

00:18:30:14 – 00:19:12:06
Speaker 2
And also interesting to note here that let’s move to the next slide that, the Nam model effectively indicated the development or explosive development of a squall line over the Mid-Atlantic region. This is a forecast from the 12 Nam model run on June 12th. So this is actually a forecast for 2100 C on June 30th. And we can see here the model indicated the develop that explosive development of a squall line over the Mid Atlantic region east of the mountains.

00:19:12:09 – 00:19:52:27
Speaker 2
If we look at what actually happened near 21 C, we can see, at that time, the development, well, it actually evolution of this squall line into a long convective system extending from Maryland to western North Carolina and eastern Tennessee. So we can see that the numerical model guidance did effectively indicate the development of an extensive, squall line system during the afternoon of June 13th, as early as the morning of June 12th.

00:19:53:00 – 00:20:18:03
Speaker 2
So this is just a very brief summary of some of the observations through satellite, as well as the, indications from the Coos, WPI, product. This just barely scrapes the surface a lot more to talk about here with the system. But I’ll go ahead and close out my portion of the presentation and hand it back over to Dan.

00:20:18:06 – 00:20:18:25
Speaker 2
Thank thank you.

00:20:19:02 – 00:20:27:10
Speaker 1
Thanks again. Does anybody have any questions for Ken?

00:20:27:12 – 00:20:36:12
Speaker 1
Okay. I will go ahead and turn it over to Scott Lindstrom at, Sims and Wisconsin.

00:20:36:14 – 00:21:03:22
Speaker 3
Okay. I just wanted to show the the satellite animation of the event over Colorado. So what do I hope you’re seeing on the screen? That yellow dot is where the severe weather event occurred. As we step forward in time to just see exactly how, unimpressive the convection looks. So you don’t really need something that looks impressive on satellite if you have the, appropriate low level thermodynamic structure.

00:21:03:22 – 00:21:31:09
Speaker 3
I mean, Ken pointed out the deep, deep, really deep, mixed layer underneath the system that allowed the winds truly, mixed down from very high levels. So this is the, and again, it’s one of those cases that occurs right after the half hour break. So 2045 to 2115. And that occurred at 2120. And if you look at the, infrared imagery for the same time, this is the 10.7 micron.

00:21:31:09 – 00:21:55:20
Speaker 3
Just put a little color enhancement on it. Again, not not much to the cloud type. You see, between 2045 and 2115, it looks like the convection is starting to fall apart. And then between 2115 and 2132 is when the, it’s when the, which is when the dome first occurred. But again, it’s just a very normal looking airmass.

00:21:55:20 – 00:22:18:23
Speaker 3
Thunderstorm is producing this, this severe gust. So very difficult, to anticipate something like this. And the MWP is going to help you, help with your situational awareness. Maybe, let you in the back of your mind, know that there’s a possibility for some extreme gusts. So that’s all I really wanted to show. Just this short animation of the visible and the infrared.

00:22:18:23 – 00:22:21:18
Speaker 3
So I’ll hand it back to Dan now. Okay.

00:22:21:20 – 00:22:32:12
Speaker 1
Next, we’ll go to, Scott back. Meyer also at Sam’s in Wisconsin.

00:22:32:14 – 00:23:01:22
Speaker 3
Okay. Hopefully my screen is up and everyone else, I can see it already. I just wanted to have a look at what’s going on in a very interesting. It’s going on at the current time. And it looks to me like the only stuff that’s of interest of, say, from Colorado towards the Arkansas area and Arkansas, it looks like you can see some hints of some early.

00:23:01:24 – 00:23:05:04
Speaker 3
Morning.

00:23:05:06 – 00:23:35:03
Speaker 3
August. And then obviously, the other item of interest in the Texas Panhandle is a pretty good, area of. Action. I was so I wanted to, in a website, take a look at what these two features looked like a little bit earlier, and talk about how they might look on high res from some of the Polar Orbiter instruments.

00:23:35:05 – 00:23:37:27
Speaker 3
So, here we are looking at.

00:23:37:29 – 00:23:38:26
Speaker 2
The early.

00:23:38:26 – 00:24:22:08
Speaker 3
Stages of the mix. As it was. It ended up right here, located in southeastern Colorado on the goes-r imagery. There were some hops that were, you know, not terribly, terribly old. Okay. Extremely cold. But if I do a comparison and I hope this works here, I have it from a little bit earlier to it. Image toggle inventory and try and get to.

00:24:22:10 – 00:24:25:17
Speaker 3
And I have to go I of my.

00:24:25:19 – 00:24:33:12
Unknown
Work go over.

00:24:33:15 – 00:24:47:21
Unknown
It.

00:24:47:23 – 00:24:54:15
Speaker 3
And I know it’s not working. You know I’m not sure what the issue is.

00:24:54:18 – 00:25:00:13
Speaker 3
I had it up earlier.

00:25:00:16 – 00:25:11:13
Speaker 3
All right, well, here’s. I’ll just see if I can do this.

00:25:11:16 – 00:25:44:05
Speaker 3
It’s not letting me get the air. I have to go out of ten or, memory for just a moment here. I apologize for the delay. Because my screen is, large enough screen to get all of the menu items on here. So I wanted to take a look at what’s happening from the air. The veers instrument was.

00:25:44:09 – 00:25:56:22
Speaker 3
Which gives us a view at a one kilometer resolution. So I’m going to try and put that enhancement on there that I had on the earlier I are.

00:25:56:24 – 00:26:00:17
Speaker 3
Those.

00:26:00:19 – 00:26:25:24
Speaker 3
Things are just not working for me here. I have never had this problem where I can overlay and toggle between images, but for some reason this morning it’s not cooperating. All right. So now I’ll go back to the larger screen. You know.

00:26:25:26 – 00:26:39:11
Speaker 3
Of course. Word planning website though. Fantastic.

00:26:39:13 – 00:26:46:04
Speaker 3
I’m not sure what happened there.

00:26:46:06 – 00:26:56:08
Speaker 3
Okay, well, I’m eating up all our time here, trying to get things straight.

00:26:56:11 – 00:27:02:08
Speaker 3
Are you able to see the apps on screen, or do I need to move it over to. Yeah, the other monitor.

00:27:02:08 – 00:27:03:15
Speaker 1
It’s good where it is now.

00:27:03:18 – 00:27:44:14
Speaker 3
Okay. Yeah. All right, so I try get in a little bit closer here. And what. All right. Well, if you recall that the, on the air here, the the coldest stops on this area is about 11 degrees or so colder. So we get an idea of, the accuracy of how cold the cloud tops are and actually which county they are in, because we don’t have a large, problem of parallax here like we do from echoes.

00:27:44:18 – 00:28:19:08
Speaker 3
And so in this case, on the, on the air imagery from the Polar Orbiter, we do get a lot. More accurate view of where they called it tops are. And try this comparison of the water vapor imagery. You can see that we do have a strong flow over the high amounts here. And let’s talk a little bit of wave action.

00:28:19:10 – 00:28:30:04
Speaker 3
Here’s what it looks like. But that goes imagery. And if I toggle between the one kilometer imagery from.

00:28:30:07 – 00:29:05:23
Speaker 3
The Mahoney’s instrument, you can see obviously the, the, it looks we do have an advantage when we’re looking at it, looking with the one kilometer, from the, what we have on board a lot of the, the polar orbiters. And one more comparison in Arkansas, I talked about the fact that there was some early morning fog.

00:29:05:26 – 00:29:35:20
Speaker 3
To get to that imagery. Okay, so here we are in Arkansas. I’m going to zoom in a little bit closer. So here is a comparison of what we see. The the Co is you know, we do see some spots here, but it’s hard to say. You know, is that fog or stratus. And it really does not look that impressive.

00:29:35:22 – 00:30:06:16
Speaker 3
But at one kilometer we are able to see that, you know, yes. A lot of these things here are areas of fog that are forming in the valleys. And so again, we like to encourage the officers, if they can, to add this via the LDM. And you can get a lot more accurate to of these,

00:30:06:18 – 00:30:16:02
Speaker 3
These.

00:30:16:05 – 00:30:26:25
Speaker 3
Look at time here. We’re actually past our time, so I that’s all I have. I hope people were able to.

00:30:26:28 – 00:30:33:08
Speaker 3
See that on a website. About my screen problems. There.

00:30:33:10 – 00:30:43:27
Speaker 1
Okay. Thanks, Scott. Yeah, we’re we’re at the end of our time now, so I’ll just ask, if anybody has any questions or comments on, any of the imagery that we’ve seen today.

00:30:44:00 – 00:31:03:10
Speaker 2
Well, yes. Just real quick, Scott Lindstrom, had showed, he goes 14 super rapid scan imagery and, Scott, where is that or where might that be available? Well, I’m referring to the, Mercatus area file. I think.

00:31:03:12 – 00:31:12:06
Speaker 3
We just talked about here at Sam’s, and it was just break it. I mean, there wasn’t any or so that or super rapid scan. I was just showing the regular 15 minute imagery.

00:31:12:09 – 00:31:20:12
Speaker 2
Oh, okay. Okay, okay. Well, yes, it still looks good. Yeah. That’s safe. Thank you.

00:31:20:14 – 00:31:22:26
Speaker 3
If you want, I can send that to you if you want it.

00:31:22:28 – 00:31:25:01
Speaker 2
Yeah. Oh, that would be great, Scott. Okay.

00:31:25:04 – 00:31:26:19
Speaker 3
Okay.

00:31:26:21 – 00:31:32:12
Speaker 1
Okay. Any other questions or comments?

00:31:32:14 – 00:31:34:12
Speaker 1
Okay. Well thanks everybody. Have a great day.