Alert archive / Texas / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 178
The Storm Prediction Center issued this severe thunderstorm watch at May 16, 2021, 6:35 PM CDT for 18 counties in Texas. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- May 16, 2021, 6:35 PM CDT (23:35 UTC)
- Expired
- May 16, 2021, 11:00 PM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
Counties Borden County, TX, Coke County, TX, Crockett County, TX, Dawson County, TX, Fisher County, TX, Glasscock County, TX, Howard County, TX, Irion County, TX, Martin County, TX, Midland County, TX, Mitchell County, TX, Nolan County, TX, Pecos County, TX, Reagan County, TX, Scurry County, TX, Sterling County, TX, Tom Green County, TX, Upton County, TX
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 10%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
9 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 16, 7:01 PM CDT | Severe Thunderstorm Warning | MAF | Upton | 44 min |
| May 16, 7:23 PM CDT | Severe Thunderstorm Warning | MAF | Glasscock, Reagan | 52 min |
| May 16, 7:29 PM CDT | Severe Thunderstorm Warning | MAF | Pecos | 61 min |
| May 16, 7:37 PM CDT | Severe Thunderstorm Warning | MAF | Howard, Mitchell | 38 min |
| May 16, 8:13 PM CDT | Severe Thunderstorm Warning | MAF | Mitchell, Scurry | 47 min |
| May 16, 8:33 PM CDT | Severe Thunderstorm Warning | SJT | Fisher, Nolan | 42 min |
| May 16, 8:40 PM CDT | Severe Thunderstorm Warning | MAF | Borden, Mitchell, Scurry | 44 min |
| May 16, 9:12 PM CDT | Severe Thunderstorm Warning | SJT | Fisher | 48 min |
| May 16, 9:16 PM CDT | Severe Thunderstorm Warning | SJT | Fisher, Jones | 44 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
Midland Regional, TX (KMAF), launched 12:00Z, 11.6 hours before the alert went out and 75 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
- 109 J/kg
- Mixed-layer CIN
- -294 J/kg
- Mixed-layer LCL
- 1288 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- -48 m²/s²
- 0-3 km storm-relative helicity
- -19 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
270
WWUS20 KWNS 162333
SEL8
SPC WW 162333
TXZ000-170400-
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 178
NWS Storm Prediction Center Norman OK
635 PM CDT Sun May 16 2021
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
West Texas
* Effective this Sunday evening from 635 PM until 1100 PM CDT.
* Primary threats include...
Isolated very large hail events to 2.5 inches in diameter
possible
Isolated damaging wind gusts to 70 mph possible
SUMMARY...A couple supercells may develop across a portion of the
Permian Basin and spread slowly east towards the Concho Valley and
Big Country this evening.
The severe thunderstorm watch area is approximately along and 50
statute miles east and west of a line from 50 miles north northeast
of Big Spring TX to 95 miles south of Midland TX. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU8).
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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 177...
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 550. Mean storm motion vector
26020.
...GramsSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 15, 9:09 PM CDT | Mesoscale Discussion | SPC | Armstrong, Briscoe, Carson, Castro, Crosby, Floyd and 11 more | 96 min |
| May 15, 9:32 PM CDT | Mesoscale Discussion | SPC | Andrews, Borden, Crane, Crockett, Dawson, Ector and 11 more | 88 min |
| May 16, 12:15 PM CDT | Mesoscale Discussion | SPC | Anderson, Bastrop, Bell, Brazos, Burleson, Cherokee and 22 more | 2 hr |
| May 16, 3:16 PM CDT | Mesoscale Discussion | SPC | Armstrong, Bailey, Briscoe, Carson, Castro, Cochran and 12 more | 119 min |
| May 16, 3:43 PM CDT | Severe Thunderstorm Watch | SPC | Armstrong, Briscoe, Carson, Castro, Childress, Collingsworth and 19 more | 7 hr |
| May 16, 3:46 PM CDT | Mesoscale Discussion | SPC | Archer, Clay, Cooke, Jack, Montague, Wichita and 1 more | 89 min |
| May 16, 5:52 PM CDT | Mesoscale Discussion | SPC | Glasscock, Howard, Irion, Midland, Reagan, Sterling | 53 min |
| May 16, 6:12 PM CDT | Mesoscale Discussion | SPC | Armstrong, Briscoe, Carson, Castro, Childress, Deaf Smith and 7 more | 93 min |
Nearby
Severe Thunderstorm Watches in Texas, 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.