Today's Experimental Operations - May 2, 2019

Today's operations will be focused over the SJT (San Angelo), FWD (Dallas/Fort Worth), and EWX (Austin/San Antonio) county warning areas.  Focus is once again ahead of an outflow boundary left over from overnight storms.  To keep with the theme this week, storms are again on-going at the start of the operations period with a severe thunderstorm watch in place over a portion of the operations area.  Supercells will be possible today but the scenario will be messy with storm interactions and mergers likely.   The main threats today are hail and high winds but a few tornadoes are possible.

Spectacular 1 min GOES satellite imagery of a Colorado supercell

Using feature following zoom to stationary view track a supercell  in ECO. Many things visible here, including uplift and twisting of stratus deck in the inflow region, anvil plume texture, and updraft texture. The parallax error ends up helping the user get more info about the vertical structure and composition of the storm - contrary to the often requested need for 'parallax corrected' imagery.



Day cloud phase 1 min of the same storm. Does not get much better than this!

-Dusty Davis

ProbSevere - Transition from hail to wind threat

ProbSevere seemed to have a pretty good handle on the dominant severe threat  as initially discrete storms early in the day,  began to congeal and grow upscale into the early evening north of the Red River. This can be shown in same sample graphics below.     The first two trend graphics are from storm objects over the northern, maturing portion of the MCS, generally north of the Red River where mainly wind damage reports were observed (and some small hail).  The second two trend graphics are from somewhat newer storms that were developing southwestward into northern Texas where primarily hail (and wind) were observed. 

- Quik Twip

GLM detects Cirrus Lightning Flashes above light rain area

Image 1


Image 2

GLM detects lightning flashes in cirrus plume in light rain area north of main convective line.  See cursor location in (Image 2) for the cirrus flash spreading northward.  -Jake Johnson

High ProbWind values with severe reports!!

The storm cluster across N TX began to gust out late in the afternoon. Line motion was ~43kt as the storms surged across Montague county just south of the Red River. There was a report of wind damage in Texas (power poles blown down) and in Oklahoma (estimated 60-70 mph winds) associated with the storm cluster.  ProbWind was as high as it has been the past couple of days in the 92-95% range during this time. Of note, the Flash Rate was very high with the identified object, at times nearing 150 fl/min and the AzShear was 'strong'. This combined with the environmental parameters helped increase the wind probs throughout the life of this cluster as it moved ENE. ProbWind was equally high with other objects to the northeast and southwest of the featured storms yet no wind reports were received from them. Interestingly though, ProbTor was ~30% with the Montague county object at this time helping draw attention to it.


Low Level AzShear (UL), Mid Level AzShear (UR), ProbHail (LL), ProbWind (LR)

GLM Total Optical Energy for early storm development

GLM Total Optical Energy product shows rapid increase of lightning in a 14 minute span for a developing thunderstorm in southwest Texas.  This is useful information to forecasters for diagnosing storm intensification which usually precedes a response on radar. 

-Jake Johnson

All-Sky products and boundaries

As many have already mentioned, the new All-Sky LAP layered PW and CAPE products are very useful tools for mesoanalysis and quick identification of key meteorological gradients (I bet my grandmother could ID the dryline below...). Earlier today, these products seemed to pick up on the outflow boundary that stretched from SE AR into southern OK/northern TX. It was extremely subtle and slightly offset from the actual boundary, but if you looked just right you could see it (tried to get a good animation, but the contrast is lost so you'll have to take my word for it...). The color table provided for these products, specifically the PW products, make identifying key/obvious boundaries easy, but the more subtle things are easily missed. I would caution anyone from using them for anything other than IDing the main players, unless the color table could be tweaked to enhance those low-to-mid range values (~0.4 to 0.8). I'm not sure it's worth exploring given these products are 6km resolution, I was just surprised to see the subtle reflection of the outflow boundary. Perhaps I'll play around with the color tables now...

--Stanley Cupp

PW Options

The AllSkyLAP Precipitable Water Product continues to be my favorite of the two options. There are too many unrealistic gradients that form within the composite merge. In this case notice how Texas seems to be especially prone to the errors where numerous sharp & and unrealistic gradients exist east of the dryline.


Top is the Blended PW & Bottom is the AllskyLAP

South Beach

NUCAPS gridded data example

An example of NUCAPS gridded data over Texas. Convection was already underway at this time, as seen by the very high pixels in south OK and north TX. This field is 850-300mb RH. The dryline is evident, however the usefulness of this and other NUCAPS gridded data is questionable for operations because of the poor resolution. With so many other much higher resolution surface and gridded data sources available, I doubt I would be using these products much at all in operations.

-Dusty Davis

NUCAPS Modified Sounding compared to sfc obs

Figure A (NUCAPS Modified sounding points 1915Z


Figure B (NUCAPS Modified sounding point near KOZA, in the moist sector)


Figure C (NUCAPS Modified sounding point near KFST, behind the dry-line)

This is a comparison of NUCAPS modified sounding for locations west/east of the dry line.

Figure C        NUCAPS Modified Temp/Dew....82/27                 KFST Metar Temp/Dew....86/35

Figure B        NUCAPS Modified Temp/Dew...75/62                  KOZA Meter Temp/Dew...79/66

-Jake Johnson