Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 169
The Storm Prediction Center issued this mesoscale discussion at Mar 13, 2021, 5:46 PM CST for 24 counties in Texas. It was in force for 89 min.
The area
The outline as issued.
The facts
- Issued
- Mar 13, 2021, 5:46 PM CST (23:46 UTC)
- Expired
- Mar 13, 2021, 7:15 PM CST
- In force
- 89 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 20
All 24 counties
Armstrong County, TX, Briscoe County, TX, Carson County, TX, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Crosby County, TX, Dickens County, TX, Donley County, TX, Floyd County, TX, Garza County, TX, Gray County, TX, Hall County, TX, Hansford County, TX, Hemphill County, TX, Hutchinson County, TX, Kent County, TX, King County, TX, Lipscomb County, TX, Motley County, TX, Ochiltree County, TX, Roberts County, TX, Stonewall County, TX, Wheeler County, TX
The radar
The Lubbock radar (KLBB), 107 km from the middle of the area, began a volume at 23:48 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, 11.8 hours before the alert went out and 120 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
- 188 J/kg
- Mixed-layer CIN
- -140 J/kg
- Mixed-layer LCL
- 540 m above ground
- 0-6 km bulk shear
- 73 kt
- 0-1 km storm-relative helicity
- 162 m²/s²
- 0-3 km storm-relative helicity
- 216 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.9
The text
As transmitted.
071 ACUS11 KWNS 132346 SWOMCD SPC MCD 132346 OKZ000-TXZ000-140115- Mesoscale Discussion 0169 NWS Storm Prediction Center Norman OK 0546 PM CST Sat Mar 13 2021 Areas affected...Eastern TX Panhandle...TX South Plains Concerning...Tornado Watch 20... Valid 132346Z - 140115Z The severe weather threat for Tornado Watch 20 continues. SUMMARY...A few strong tornadoes remain possible with ongoing supercells across ww020. DISCUSSION...A productive corridor of discrete supercells (half dozen or so) is progressing across the western half of ww020 early this evening. Several tornadoes, some potentially significant, have been noted with long-lived, strong circulations. Air mass remains quite moist and buoyant just ahead of this activity, especially across the southeastern TX Panhandle/northwest TX where SBCAPE remains on the order of 2000 J/kg. LLJ is focused along the TX/OK border but this will gradually shift east over the next few hours as strong mid-level height falls spread across the southern High Plains. Latest thinking is an elongated severe squall line should emerge over the next few hours due to the large-scale forcing. This MCS is expected to progress into western OK, trailing across northwest TX by 03z. Until this squall line emerges, tornadoes can be expected with the strongest circulations. ..Darrow.. 03/13/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OUN...LUB...AMA... LAT...LON 33010174 36300145 36309982 33010020 33010174
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 12, 8:11 PM CST | Mesoscale Discussion | SPC | Baylor, Briscoe, Childress, Cottle, Crosby, Dickens and 18 more | 64 min |
| Mar 12, 8:38 PM CST | Severe Thunderstorm Watch | SPC | Armstrong, Baylor, Briscoe, Carson, Childress, Cochran and 29 more | 5 hr |
| Mar 12, 11:08 PM CST | Mesoscale Discussion | SPC | Armstrong, Briscoe, Carson, Castro, Childress, Collingsworth and 26 more | 2 hr |
| Mar 13, 1:06 AM CST | Mesoscale Discussion | SPC | Childress, Cottle, Foard, Hardeman, Motley | 54 min |
| Mar 13, 7:36 AM CST | Mesoscale Discussion | SPC | Dallam, Hartley, Moore, Oldham, Sherman | 2 hr |
| Mar 13, 11:48 AM CST | Mesoscale Discussion | SPC | Bailey, Castro, Cochran, Deaf Smith, Hale, Hockley and 7 more | 117 min |
| Mar 13, 12:36 PM CST | Tornado Watch | SPC | Bailey, Castro, Cochran, Deaf Smith, Hale, Hockley and 8 more | 5 hr |
| Mar 13, 1:52 PM CST | Mesoscale Discussion | SPC | Armstrong, Briscoe, Carson, Childress, Collingsworth, Cottle and 9 more | 113 min |
| Mar 13, 2:26 PM CST | Tornado Watch | SPC | Armstrong, Briscoe, Carson, Childress, Collingsworth, Cottle and 19 more | 7 hr |
| Mar 13, 2:39 PM CST | Mesoscale Discussion | SPC | Andrews, Borden, Crane, Crockett, Dawson, Ector and 18 more | 2 hr |
| Mar 13, 3:23 PM CST | Tornado Watch | SPC | Borden, Coke, Crane, Crockett, Dawson, Fisher and 18 more | 6 hr |
| Mar 13, 3:46 PM CST | Mesoscale Discussion | SPC | Armstrong, Briscoe, Carson, Donley, Floyd, Hale and 5 more | 59 min |
| Mar 13, 4:10 PM CST | Mesoscale Discussion | SPC | Armstrong, Carson, Hutchinson, Randall | 65 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.