Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 231
The Storm Prediction Center issued this mesoscale discussion at Mar 22, 2021, 5:25 PM CDT for 18 counties in Oklahoma; 47 counties in Texas. It was in force for 65 min.
The area
The outline as issued.
The facts
- Issued
- Mar 22, 2021, 5:25 PM CDT (22:25 UTC)
- Expired
- Mar 22, 2021, 6:30 PM CDT
- In force
- 65 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 44
All 65 counties
Caddo County, OK, Carter County, OK, Comanche County, OK, Cotton County, OK, Garvin County, OK, Grady County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Jefferson County, OK, Kiowa County, OK, Love County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Archer County, TX, Baylor County, TX, Bosque County, TX, Brown County, TX, Callahan County, TX, Clay County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Concho County, TX, Cooke County, TX, Coryell County, TX, Dallas County, TX, Denton County, TX, Eastland County, TX, Ellis County, TX, Erath County, TX, Foard County, TX, Grayson County, TX, Hamilton County, TX, Hardeman County, TX, Haskell County, TX, Hill County, TX, Hood County, TX, Jack County, TX, Johnson County, TX, Jones County, TX, Knox County, TX, Lampasas County, TX, McCulloch County, TX, McLennan County, TX, Mills County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Runnels County, TX, San Saba County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Taylor County, TX, Throckmorton County, TX, Wichita County, TX, Wilbarger County, TX, Wise County, TX, Young County, TX
The radar
The Dyess AFB radar (KDYX), 97 km from the middle of the area, began a volume at 22:26 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Fort Worth, TX (KFWD), launched 12:00Z, 10.4 hours before the alert went out and 155 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 820 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 222 m²/s²
- 0-3 km storm-relative helicity
- 272 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
900
ACUS11 KWNS 222225
SWOMCD
SPC MCD 222225
OKZ000-TXZ000-222330-
Mesoscale Discussion 0231
NWS Storm Prediction Center Norman OK
0525 PM CDT Mon Mar 22 2021
Areas affected...southwestern Oklahoma through portions of west and
central Texas
Concerning...Severe Thunderstorm Watch 44...
Valid 222225Z - 222330Z
The severe weather threat for Severe Thunderstorm Watch 44
continues.
SUMMARY...The severe threat continues across WW 44. Downstream
watches may be considered across north and/or central Texas and
vicinity over the next couple of hours.
DISCUSSION...Recent radar trends indicate a sharpening of convective
bands/linear segments across ongoing portions of WW 44. Strong to
severe wind gusts have been reported with the linear segment
progressing through southwestern Oklahoma. The storms are in a
strongly sheared environment, with upscale growth being supported by
ascent from and approaching mid-level wave near the NM/TX border.
Despite modest destabilization due to only mid/upper 50s F dewpoints
across the warm sector, continued upscale growth of convection is
possible, with the main threat being damaging wind gusts near the
convective segments. Low-level shear will also increase tonight as
850mb flow increased to around 55 knots. One or two strongly forced
linear segments across downstream areas of southern Oklahoma and
north/central Texas over the next several hours. The probability of
a downstream watch being needed is 60%.
..Cook/Guyer.. 03/22/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FWD...OUN...EWX...SJT...LUB...
LAT...LON 35299968 35579903 35439777 34699682 33479652 32259659
31509702 30969827 31009936 31259984 31579995 32320016
33060001 33649985 34509986 34909985 35299968SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 22, 2:31 PM CDT | Severe Thunderstorm Watch | SPC | Comanche, Cotton, Greer, Harmon, Jackson, Kiowa and 1 more | 4 hr |
| Mar 22, 12:01 PM CDT | Mesoscale Discussion | SPC | Armstrong, Borden, Briscoe, Childress, Collingsworth, Cottle and 20 more | 2 hr |
| Mar 22, 2:51 PM CDT | Mesoscale Discussion | SPC | Brown, Coke, Coleman, Comanche, Concho, Crockett and 14 more | 2 hr |
| Mar 22, 4:24 PM CDT | Mesoscale Discussion | SPC | Bailey, Cochran, Crosby, Garza, Hale, Hockley and 5 more | 66 min |
| Mar 22, 6:05 PM CDT | Severe Thunderstorm Watch | SPC | Anderson, Bell, Blanco, Bosque, Burnet, Collin and 43 more | 7 hr |
Nearby
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.