Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 596
The Storm Prediction Center issued this mesoscale discussion at May 11, 2021, 5:23 PM CDT for 17 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 11, 2021, 5:23 PM CDT (22:23 UTC)
- Expired
- May 11, 2021, 7:30 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 165
Counties Atascosa County, TX, Bee County, TX, Colorado County, TX, DeWitt County, TX, Goliad County, TX, Gonzales County, TX, Guadalupe County, TX, Jackson County, TX, Karnes County, TX, Lavaca County, TX, Live Oak County, TX, McMullen County, TX, Refugio County, TX, San Patricio County, TX, Victoria County, TX, Wharton County, TX, Wilson County, TX
The radar
The Austin/San Antonio radar (KEWX), 116 km from the middle of the area, began a volume at 22:27 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Corpus Christi, TX (KCRP), launched 12:00Z, 10.4 hours before the alert went out and 123 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 1953 J/kg
- Mixed-layer CIN
- -175 J/kg
- Mixed-layer LCL
- 825 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- -52 m²/s²
- 0-3 km storm-relative helicity
- 33 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -2.5
The text
As transmitted.
663
ACUS11 KWNS 112224
SWOMCD
SPC MCD 112223
TXZ000-120030-
Mesoscale Discussion 0596
NWS Storm Prediction Center Norman OK
0523 PM CDT Tue May 11 2021
Areas affected...Middle Texas Coast
Concerning...Severe Thunderstorm Watch 165...
Valid 112223Z - 120030Z
The severe weather threat for Severe Thunderstorm Watch 165
continues.
SUMMARY...A potential for large hail and wind damage will continue
across the eastern part of WW 165. The severe threat may affect
areas to the east of the watch across the middle Texas Coast later
this evening, where new watch issuance or a watch extension may be
needed.
DISCUSSION...The latest radar imagery from San Antonio shows two
supercell thunderstorms ongoing to the south of the San Antonio
Metro. These storms are located just to the northwest of a pocket of
strong instability with the RAP estimating MLCAPE in the 3500 to
4000 J/kg range. These storms are being supported by a subtle
shortwave trough moving through south-central Texas, evident on
water vapor imagery. RAP forecast soundings near San Antonio early
this evening have 0-6 km shear near 40 kt with 700-500 mb lapse
rates around 7.0 C/km. This will be favorable for large hail with
the stronger updraft cores. A wind damage threat will also be
likely. The severe threat may affect areas to the east of the watch
later this evening, especially if the right-moving supercell in the
southeast part of WW 165 can remain intact as it approaches the
eastern edge of the ongoing watch.
..Broyles.. 05/11/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...HGX...CRP...EWX...
LAT...LON 28429673 27909764 27919830 28279869 28779881 29359870
29689789 29759703 29699648 29279605 28889612 28589646
28429673SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 10, 8:01 PM CDT | Mesoscale Discussion | SPC | Atascosa, Bexar, Dimmit, Frio, Kendall, Medina and 1 more | 119 min |
| May 11, 4:44 AM CDT | Mesoscale Discussion | SPC | Andrews, Borden, Coke, Crane, Crosby, Dawson and 26 more | 2 hr |
| May 11, 10:13 AM CDT | Mesoscale Discussion | SPC | Anderson, Bell, Bosque, Brown, Burnet, Callahan and 45 more | 62 min |
| May 11, 1:22 PM CDT | Mesoscale Discussion | SPC | Dimmit, Kinney, Maverick, Terrell, Val Verde, Zavala | 2 hr |
| May 11, 1:59 PM CDT | Mesoscale Discussion | SPC | Anderson, Bell, Burleson, Burnet, Cherokee, Coryell and 18 more | 2 hr |
| May 11, 3:04 PM CDT | Severe Thunderstorm Watch | SPC | Anderson, Angelina, Brazos, Burleson, Cherokee, Freestone and 17 more | 4 hr |
| May 11, 3:41 PM CDT | Severe Thunderstorm Watch | SPC | Atascosa, Bandera, Bastrop, Bexar, Blanco, Caldwell and 29 more | 10 hr |
| May 11, 4:37 PM CDT | Mesoscale Discussion | SPC | Angelina, Grimes, Hardin, Houston, Jasper, Liberty and 8 more | 83 min |
| May 11, 5:22 PM CDT | Severe Thunderstorm Watch | SPC | Hardin, Jasper, Newton, Tyler | 4 hr |
| May 11, 6:36 PM CDT | Mesoscale Discussion | SPC | Hardin, Jasper, Newton, Polk, Tyler | 84 min |
Nearby
Mesoscale Discussions in Texas, 2021Every mesoscale discussion in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.