Alert archive / Texas / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 180

May 16, 202116 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at May 16, 2021, 9:38 PM CDT for 16 counties in Texas. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
May 16, 2021, 9:38 PM CDT (02:38 UTC)
Expired
May 17, 2021, 2:00 AM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
65 kt

Counties Archer County, TX, Baylor County, TX, Clay County, TX, Foard County, TX, Hardeman County, TX, Haskell County, TX, Jack County, TX, Jones County, TX, Knox County, TX, Palo Pinto County, TX, Shackelford County, TX, Stephens County, TX, Throckmorton County, TX, Wichita County, TX, Wilbarger County, TX, Young County, TX

The radar

The Altus AFB radar (KFDR), 80 km from the middle of the area, began a volume at 02:41 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
10%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
40%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
40%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 16, 9:43 PM CDTSevere Thunderstorm WarningFWDJack62 min
May 16, 9:59 PM CDTSevere Thunderstorm WarningOUNFoard, Hardeman, Knox76 min
May 16, 10:03 PM CDTSevere Thunderstorm WarningSJTHaskell, Jones, Shackelford42 min
May 16, 10:29 PM CDTSevere Thunderstorm WarningSJTHaskell36 min
May 16, 10:31 PM CDTSevere Thunderstorm WarningOUNKnox44 min
May 16, 10:43 PM CDTSevere Thunderstorm WarningFWDJack62 min
May 16, 10:46 PM CDTTornado WarningSJTHaskell, Jones44 min
May 16, 11:06 PM CDTSevere Thunderstorm WarningOUNBaylor, Knox39 min
May 16, 11:32 PM CDTSevere Thunderstorm WarningOUNBaylor, Foard, Knox, Wilbarger58 min
May 16, 11:38 PM CDTSevere Thunderstorm WarningOUNBaylor52 min
May 16, 11:39 PM CDTSevere Thunderstorm WarningFWDJack, Parker, Wise66 min
May 17, 12:14 AM CDTSevere Thunderstorm WarningOUNArcher, Baylor, Knox, Wichita, Wilbarger38 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 00:00Z, 2.6 hours before the alert went out and 173 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.

Skew-T log-pSkew-T log-p diagram, Fort Worth, TX at 00:00Z on 2021-05-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 496 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 00:00Z on 2021-05-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
496 J/kg
Mixed-layer CIN
-83 J/kg
Mixed-layer LCL
815 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
137 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

The text

As transmitted.

730 
WWUS20 KWNS 170235
SEL0  
SPC WW 170235
TXZ000-170700-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 180
NWS Storm Prediction Center Norman OK
935 PM CDT Sun May 16 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Western North Texas

* Effective this Sunday night and Monday morning from 935 PM
  until 200 AM CDT.

* Primary threats include...
  Scattered damaging winds and isolated significant gusts to 75
    mph possible
  Scattered large hail and isolated very large hail events to 2.5
    inches in diameter possible

SUMMARY...Multiple supercells producing large hail should move
across a portion of western North Texas through midnight,
potentially merging with a longer-lived cluster producing damaging
winds that should spread southeast.

The severe thunderstorm watch area is approximately along and 55
statute miles east and west of a line from 40 miles northwest of
Wichita Falls TX to 105 miles south southwest of Wichita Falls TX.
For a complete depiction of the watch see the associated watch
outline update (WOUS64 KWNS WOU0).

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...WW 178...WW 179...

AVIATION...A few severe thunderstorms with hail surface and aloft to
2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
30025.

...Grams

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 17, 1:09 AM CDTMesoscale DiscussionSPCComanche, Cotton, Jefferson, Stephens, Tillman96 min
May 17, 1:39 PM CDTMesoscale DiscussionSPCCimarron2 hr
May 17, 2:39 PM CDTSevere Thunderstorm WatchSPCCimarron, Texas8 hr
May 17, 5:10 PM CDTMesoscale DiscussionSPCCimarron, Texas2 hr
May 16, 7:08 PM CDTSevere Thunderstorm WatchSPCCottle, Crosby, Dickens, Floyd, Garza, Hale and 8 more6 hr
May 16, 8:54 PM CDTMesoscale DiscussionSPCBriscoe, Cottle, Foard, Hall, King, Knox and 1 more96 min
May 16, 10:46 PM CDTMesoscale DiscussionSPCBaylor, Cottle, Dickens, Foard, Haskell, King and 3 more59 min
May 17, 9:18 AM CDTMesoscale DiscussionSPCJasper, Jefferson, Newton, Orange117 min
May 17, 12:47 PM CDTMesoscale DiscussionSPCAustin, Bastrop, Bell, Blanco, Brazoria, Brazos and 29 more88 min
May 17, 2:11 PM CDTMesoscale DiscussionSPCAndrews, Bailey, Borden, Castro, Cochran, Crane and 20 more2 hr
May 17, 3:04 PM CDTTornado WatchSPCAndrews, Bailey, Borden, Briscoe, Castro, Cochran and 39 more8 hr
May 17, 4:44 PM CDTTornado WatchSPCBaylor, Childress, Cottle, Fisher, Foard, Hardeman and 10 more6 hr
May 17, 4:53 PM CDTMesoscale DiscussionSPCBaylor, Callahan, Childress, Cottle, Fisher, Foard and 11 more97 min
May 17, 5:36 PM CDTMesoscale DiscussionSPCAndrews, Armstrong, Bailey, Borden, Briscoe, Castro and 38 more84 min
May 17, 6:13 PM CDTMesoscale DiscussionSPCDimmit, La Salle, Webb92 min
May 17, 6:40 PM CDTSevere Thunderstorm WatchSPCDimmit, Frio, La Salle, Maverick, Webb, Zavala4 hr

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; radar from the NEXRAD Level II archive.