Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 1574
The Storm Prediction Center issued this mesoscale discussion at Aug 21, 2021, 3:22 PM CDT for 11 counties in Oklahoma; 12 counties in Texas. It was in force for 113 min.
The area
The outline as issued.
The facts
- Issued
- Aug 21, 2021, 3:22 PM CDT (20:22 UTC)
- Expired
- Aug 21, 2021, 5:15 PM CDT
- In force
- 113 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
All 23 counties
Alfalfa County, OK, Beckham County, OK, Blaine County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Major County, OK, Roger Mills County, OK, Washita County, OK, Woods County, OK, Woodward County, OK, Armstrong County, TX, Carson County, TX, Collingsworth County, TX, Donley County, TX, Gray County, TX, Hemphill County, TX, Hutchinson County, TX, Lipscomb County, TX, Ochiltree County, TX, Potter County, TX, Roberts County, TX, Wheeler County, TX
The radar
The Vance AFB radar (KVNX), 174 km from the middle of the area, began a volume at 20:22 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
Amarillo Airport, TX (KAMA), launched 12:00Z, 8.4 hours before the alert went out and 191 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
- 611 J/kg
- Mixed-layer CIN
- -143 J/kg
- Mixed-layer LCL
- 1642 m above ground
- 0-6 km bulk shear
- 9 kt
- 0-1 km storm-relative helicity
- 16 m²/s²
- 0-3 km storm-relative helicity
- 76 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
418
ACUS11 KWNS 212022
SWOMCD
SPC MCD 212022
OKZ000-TXZ000-212215-
Mesoscale Discussion 1574
NWS Storm Prediction Center Norman OK
0322 PM CDT Sat Aug 21 2021
Areas affected...the Texas Panhandle into northwest Oklahoma
Concerning...Severe potential...Watch unlikely
Valid 212022Z - 212215Z
Probability of Watch Issuance...5 percent
SUMMARY...Storms will continue to increase in coverage over the next
several hours, and a few may become marginally severe with localized
gust potential or marginal hail.
DISCUSSION...Surface analysis shows a stalled front/theta-e gradient
extending from southeast NM across the TX Panhandle and across
northern OK. Although warm aloft, the air mass continues to warm
with ample boundary-layer moisture in place, resulting in MLCAPE
over 2000 J/kg. Shear will remain weak across the region, though
low-level theta-e may increase north of the front this evening with
modest 850 mb flow.
A few storms have already developed from the northeast TX Panhandle
southwestward into NM, and lift along the front and an uncapped air
mass should result in increasing storm coverage through early
evening. Both cells and clusters of storms are possible, and a few
may produce strong/low-end severe gusts or brief periods of mainly
marginal hail.
..Jewell/Guyer.. 08/21/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...OUN...AMA...
LAT...LON 36929846 36759793 36429783 35979800 35679834 35319893
35039964 34860041 34800118 34920176 35210199 35590184
36150148 36620062 36859895 36929846Nearby
Mesoscale Discussions in Texas, 2021Mesoscale Discussions in Oklahoma, 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.