Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 374
The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2021, 9:26 PM CDT for 16 counties in Texas. It was in force for 64 min.
The area
The outline as issued.
The facts
- Issued
- Apr 12, 2021, 9:26 PM CDT (02:26 UTC)
- Expired
- Apr 12, 2021, 10:30 PM CDT
- In force
- 64 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 93
Counties Burnet County, TX, Concho County, TX, Edwards County, TX, Gillespie County, TX, Kerr County, TX, Kimble County, TX, Kinney County, TX, Llano County, TX, Mason County, TX, McCulloch County, TX, Menard County, TX, Real County, TX, San Saba County, TX, Schleicher County, TX, Sutton County, TX, Val Verde County, TX
The radar
The Laughlin AFB radar (KDFX), 121 km from the middle of the area, began a volume at 02:25 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
Del Rio, TX (KDRT), launched 00:00Z, 2.4 hours before the alert went out and 140 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
- 2255 J/kg
- Mixed-layer CIN
- -208 J/kg
- Mixed-layer LCL
- 1434 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 111 m²/s²
- 0-3 km storm-relative helicity
- 206 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.6
The text
As transmitted.
847
ACUS11 KWNS 130227
SWOMCD
SPC MCD 130226
TXZ000-130330-
Mesoscale Discussion 0374
NWS Storm Prediction Center Norman OK
0926 PM CDT Mon Apr 12 2021
Areas affected...portions of southwest Texas
Concerning...Severe Thunderstorm Watch 93...
Valid 130226Z - 130330Z
The severe weather threat for Severe Thunderstorm Watch 93
continues.
SUMMARY...A localized severe hail threat may continue with existing
storms for a couple more hours. A localized extension of Severe
Thunderstorm Watch #093 may be needed if storms maintain their
intensity.
DISCUSSION...Two discrete supercells have initiated along the
trailing portion of a near-stationary cold front across Sutton and
Kimble Counties in southwest Texas. Latest MRMS mosaic radar data
shows 50+ dBZ cores reaching 35 kft, with MESH values nearing 2.0
inch diameters. Despite the intensity of the ongoing storms,
convective inhibition is gradually increasing in the midst of
nocturnal cooling. As such, these storms are not expected to be
particularly long-lived. Still, storms may continue for another hour
or so while producing severe hail given the presence of 9+ C/km
700-500 mb lapse rates (per 00Z DRT observed sounding) and resultant
1000-1500 J/kg MUCAPE (when modified to match the latest KJCT METAR
observations, representative of the storm-relative environment). A
2.0 inch stone also cannot be completely ruled out. A localized
extension of WW 093 could be necessary should the storms maintain
intensity through 03Z.
..Squitieri.. 04/13/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FWD...EWX...SJT...MAF...
LAT...LON 29680188 30900087 31399988 31529933 31369865 31059814
30659818 30359885 29829956 29440003 29120029 28960070
29680188SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 12, 10:41 PM CDT | Mesoscale Discussion | SPC | Callahan, Fisher, Jones, Nolan, Palo Pinto, Shackelford and 4 more | 2 hr |
| Apr 13, 3:43 PM CDT | Mesoscale Discussion | SPC | Cherokee, Houston, Nacogdoches, Shelby | 2 hr |
| Apr 13, 4:37 PM CDT | Mesoscale Discussion | SPC | Andrews, Archer, Baylor, Borden, Clay, Coke and 28 more | 2 hr |
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.