Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 375
The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2021, 10:41 PM CDT for 10 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 12, 2021, 10:41 PM CDT (03:41 UTC)
- Expired
- Apr 13, 2021, 12:45 AM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
Counties Callahan County, TX, Fisher County, TX, Jones County, TX, Nolan County, TX, Palo Pinto County, TX, Shackelford County, TX, Stephens County, TX, Taylor County, TX, Throckmorton County, TX, Young County, TX
The radar
The Dyess AFB radar (KDYX), 51 km from the middle of the area, began a volume at 03:41 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
Fort Worth, TX (KFWD), launched 00:00Z, 3.7 hours before the alert went out and 234 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
- 1192 J/kg
- Mixed-layer CIN
- -58 J/kg
- Mixed-layer LCL
- 1812 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- 14 m²/s²
- 0-3 km storm-relative helicity
- 216 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.7
The text
As transmitted.
678 ACUS11 KWNS 130341 SWOMCD SPC MCD 130341 TXZ000-130545- Mesoscale Discussion 0375 NWS Storm Prediction Center Norman OK 1041 PM CDT Mon Apr 12 2021 Areas affected...Parts of west Texas Concerning...Severe potential...Watch unlikely Valid 130341Z - 130545Z Probability of Watch Issuance...20 percent SUMMARY...Scattered thunderstorms are increasing across the Big Country of west Texas. Some hail threat will be noted with this activity, but a severe thunderstorm watch is not currently anticipated. DISCUSSION...Weak low-level warm advection, atop a cooler post frontal boundary layer, appears to be the primary forcing mechanism for recent increase in elevated convection across the Big Country of west TX. Scattered strong storms are expanding in areal coverage from Taylor to Stephens County. This activity is likely producing at least some hail, possibly in excess of one inch at times. Latest satellite imagery suggests new updrafts are deepening as far west as eastern Mitchell County and lightning will likely be observed soon with these updrafts. Latest thinking is a broadening corridor of elevated convection will stretch from north of I-20 between MAF-ABI, extending east-northeast toward Young/Jack County over the next few hours. While isolated one-inch type stones may be noted at times, intensity/coverage of these storms should not warrant a severe thunderstorm watch. ..Darrow/Grams.. 04/13/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FWD...OUN...SJT...LUB...MAF... LAT...LON 32760089 33439852 32729816 32249933 32030092 32760089
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 12, 9:26 PM CDT | Mesoscale Discussion | SPC | Burnet, Concho, Edwards, Gillespie, Kerr, Kimble and 10 more | 64 min |
| 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.