Alert archive / Texas / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 12
The Storm Prediction Center issued this severe thunderstorm watch at Feb 28, 2021, 10:43 AM CST for 11 counties in Arkansas; 4 counties in Oklahoma; 24 counties in Texas. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 28, 2021, 10:43 AM CST (16:43 UTC)
- Expired
- Feb 28, 2021, 6:00 PM CST
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
All 39 counties
Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Montgomery County, AR, Nevada County, AR, Pike County, AR, Polk County, AR, Scott County, AR, Sevier County, AR, Choctaw County, OK, LeFlore County, OK, McCurtain County, OK, Pushmataha County, OK, Bowie County, TX, Camp County, TX, Cass County, TX, Collin County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Fannin County, TX, Franklin County, TX, Grayson County, TX, Hopkins County, TX, Hunt County, TX, Kaufman County, TX, Lamar County, TX, Marion County, TX, Morris County, TX, Rains County, TX, Red River County, TX, Rockwall County, TX, Tarrant County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX
The radar
The Dallas/Ft Worth radar (KFWS), 179 km from the middle of the area, began a volume at 16:45 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 60%
- One or more hailstones of 2 inches or more
- 60%
- Six or more combined severe hail and wind reports
- 90%
Warnings issued inside it
6 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 28, 11:18 AM CST | Severe Thunderstorm Warning | FWD | Collin, Cooke, Denton, Grayson | 57 min |
| Feb 28, 11:39 AM CST | Severe Thunderstorm Warning | TSA | Choctaw, Pushmataha | 38 min |
| Feb 28, 12:52 PM CST | Severe Thunderstorm Warning | TSA | Choctaw, Pushmataha | 23 min |
| Feb 28, 12:57 PM CST | Severe Thunderstorm Warning | SHV | McCurtain | 17 min |
| Feb 28, 1:02 PM CST | Severe Thunderstorm Warning | TSA | Choctaw | 28 min |
| Feb 28, 1:34 PM CST | Severe Thunderstorm Warning | SHV | McCurtain | 26 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Fort Worth, TX (KFWD), launched 12:00Z, 4.7 hours before the alert went out and 163 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
- 1316 J/kg
- Mixed-layer CIN
- -80 J/kg
- Mixed-layer LCL
- 666 m above ground
- 0-6 km bulk shear
- 71 kt
- 0-1 km storm-relative helicity
- 165 m²/s²
- 0-3 km storm-relative helicity
- 109 m²/s²
- Significant tornado parameter
- 1.2
- Supercell composite
- 3.6
The text
As transmitted.
087
WWUS20 KWNS 281641
SEL2
SPC WW 281641
ARZ000-OKZ000-TXZ000-010000-
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 12
NWS Storm Prediction Center Norman OK
1045 AM CST Sun Feb 28 2021
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southwest Arkansas
Southeast Oklahoma
Northeast Texas
* Effective this Sunday morning and evening from 1045 AM until
600 PM CST.
* Primary threats include...
Scattered large hail and isolated very large hail events to 2.5
inches in diameter likely
Scattered damaging wind gusts to 70 mph possible
A tornado or two possible
SUMMARY...Thunderstorms will continue to develop and intensify over
parts of northeast Texas and southeast Oklahoma through the
afternoon, posing a risk of large hail and damaging winds. Storms
will spread into western Arkansas in a few hours. An isolated
tornado is also possible.
The severe thunderstorm watch area is approximately along and 65
statute miles north and south of a line from 25 miles west of Dallas
TX to 55 miles east of De Queen AR. For a complete depiction of the
watch see the associated watch outline update (WOUS64 KWNS WOU2).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
AVIATION...A few severe thunderstorms with hail surface and aloft to
2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 450. Mean storm motion vector
25035.
...HartSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 28, 9:59 AM CST | Mesoscale Discussion | SPC | Howard, Polk, Sevier | 91 min |
| Feb 28, 1:01 PM CST | Mesoscale Discussion | SPC | Arkansas, Clark, Clay, Cleburne, Cleveland, Conway and 32 more | 119 min |
| Feb 28, 2:22 PM CST | Tornado Watch | SPC | Arkansas, Bradley, Calhoun, Clark, Clay, Cleburne and 32 more | 8 hr |
| Feb 28, 2:25 PM CST | Mesoscale Discussion | SPC | Hempstead, Howard, Little River, Miller, Pike, Sevier | 2 hr |
| Feb 28, 4:40 PM CST | Mesoscale Discussion | SPC | Arkansas, Bradley, Calhoun, Clark, Cleveland, Craighead and 23 more | 95 min |
| Feb 28, 5:28 PM CST | Mesoscale Discussion | SPC | Hempstead, Howard, Lafayette, Little River, Miller, Nevada and 2 more | 2 hr |
| Feb 28, 5:54 PM CST | Severe Thunderstorm Watch | SPC | Columbia, Hempstead, Lafayette, Miller, Nevada, Union | 4 hr |
| Feb 28, 1:47 AM CST | Mesoscale Discussion | SPC | Cleveland, Creek, Lincoln, Mayes, Okfuskee, Oklahoma and 8 more | 2 hr |
Nearby
Severe Thunderstorm Watches in Texas, 2021Severe Thunderstorm Watches in Arkansas, 2021Severe Thunderstorm Watches in Oklahoma, 2021Every severe thunderstorm watch 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.