Alert archive / Texas / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 191

May 19, 202114 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at May 19, 2021, 5:24 AM CDT for 14 counties in Texas. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
May 19, 2021, 5:24 AM CDT (10:24 UTC)
Expired
May 19, 2021, 1:00 PM CDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Brooks County, TX, Cameron County, TX, Duval County, TX, Hidalgo County, TX, Jim Hogg County, TX, Jim Wells County, TX, Kenedy County, TX, Kleberg County, TX, Nueces County, TX, San Patricio County, TX, Starr County, TX, Webb County, TX, Willacy County, TX, Zapata County, TX

The radar

The Corpus Christi radar (KCRP), 87 km from the middle of the area, began a volume at 10:27 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
50%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 19, 6:27 AM CDTSevere Thunderstorm WarningBROJim Hogg, Zapata33 min
May 19, 6:41 AM CDTSevere Thunderstorm WarningCRPBee, Jim Wells, Live Oak, San Patricio22 min
May 19, 6:51 AM CDTSevere Thunderstorm WarningBROStarr39 min
May 19, 7:09 AM CDTFlash Flood WarningCRPJim Wells, Nueces, San Patricio6 hr
May 19, 7:11 AM CDTFlash Flood WarningBROStarr, Zapata2 hr
May 19, 7:11 AM CDTSevere Thunderstorm WarningBROHidalgo, Starr64 min
May 19, 7:12 AM CDTFlash Flood WarningBROJim Hogg, Zapata3 hr
May 19, 7:17 AM CDTFlash Flood WarningBROJim Hogg3 hr
May 19, 7:17 AM CDTFlash Flood WarningCRPKleberg, Nueces6 hr
May 19, 7:27 AM CDTSevere Thunderstorm WarningBROStarr, Zapata63 min
May 19, 7:47 AM CDTSevere Thunderstorm WarningBROBrooks, Hidalgo, Jim Hogg, Starr43 min
May 19, 7:51 AM CDTTornado WarningBROBrooks, Hidalgo, Starr24 min
May 19, 7:58 AM CDTFlash Flood WarningCRPSan Patricio6 hr
May 19, 8:12 AM CDTTornado WarningBROHidalgo18 min
May 19, 8:21 AM CDTSevere Thunderstorm WarningBROBrooks, Cameron, Hidalgo, Jim Hogg, Kenedy, Starr and 1 more39 min
May 19, 8:26 AM CDTFlash Flood WarningBROJim Hogg113 min
May 19, 8:46 AM CDTFlash Flood WarningCRPKleberg, Nueces4 hr
May 19, 8:47 AM CDTTornado WarningBROBrooks13 min
May 19, 8:58 AM CDTSevere Thunderstorm WarningBROBrooks, Cameron, Hidalgo, Kenedy, Willacy47 min
May 19, 9:05 AM CDTTornado WarningBROKenedy, Willacy10 min
May 19, 9:11 AM CDTTornado WarningBROKenedy, Willacy19 min
May 19, 9:28 AM CDTTornado WarningBROKenedy17 min
May 19, 9:44 AM CDTTornado WarningBROWillacy16 min
May 19, 9:48 AM CDTFlash Flood WarningBROHidalgo4 hr
May 19, 9:50 AM CDTFlash Flood WarningBROHidalgo4 hr
May 19, 9:55 AM CDTFlash Flood WarningCRPAransas, San Patricio3 hr
May 19, 10:15 AM CDTFlash Flood WarningBROHidalgo, Willacy4 hr
May 19, 10:18 AM CDTFlash Flood WarningBROHidalgo5 hr
May 19, 10:21 AM CDTFlash Flood WarningBROWillacy5 hr
May 19, 10:24 AM CDTFlash Flood WarningBROCameron, Hidalgo, Willacy5 hr
May 19, 10:27 AM CDTFlash Flood WarningBROCameron4 hr
May 19, 10:29 AM CDTFlash Flood WarningBROCameron, Hidalgo4 hr
May 19, 11:00 AM CDTFlash Flood WarningBROCameron, Willacy5 hr
May 19, 11:30 AM CDTFlash Flood WarningBROCameron5 hr
May 19, 12:15 PM CDTFlash Flood WarningBROCameron4 hr

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 00:00Z, 10.4 hours before the alert went out and 96 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, Corpus Christi, TX at 00:00Z on 2021-05-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2386 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, Corpus Christi, TX at 00:00Z on 2021-05-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 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
2386 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
721 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
114 m²/s²
Significant tornado parameter
0.8
Supercell composite
6.4

Open this sounding in Storm Lab

The text

As transmitted.

294 
WWUS20 KWNS 191017
SEL1  
SPC WW 191017
TXZ000-CWZ000-191800-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 191
NWS Storm Prediction Center Norman OK
520 AM CDT Wed May 19 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Deep South Texas
  Coastal Waters

* Effective this Wednesday morning and afternoon from 520 AM
  until 100 PM CDT.

* Primary threats include...
  Scattered large hail and isolated very large hail events to 2
    inches in diameter possible
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...A large cluster of thunderstorms currently forming over
northern Mexico will move/develop eastward across Deep South Texas
this morning.  Scattered intense thunderstorms are possible,
including the risk of large hail and locally damaging wind gusts.

The severe thunderstorm watch area is approximately along and 75
statute miles east and west of a line from 30 miles northwest of
Alice TX to 15 miles south southwest of Mcallen TX. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU1).

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 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 550. Mean storm motion vector
25025.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 18, 7:34 PM CDTTornado WatchSPCAustin, Bee, Brazoria, Chambers, Colorado, Fort Bend and 17 more6 hr
May 18, 8:00 PM CDTMesoscale DiscussionSPCCherokee, Gregg, Harrison, Marion, Nacogdoches, Panola and 4 more60 min
May 18, 8:54 PM CDTMesoscale DiscussionSPCAustin, Fort Bend, Harris, Jackson, Montgomery, Waller and 1 more96 min
May 18, 10:39 PM CDTMesoscale DiscussionSPCHardin, Jasper, Jefferson, Newton, Orange, Tyler96 min
May 18, 11:00 PM CDTMesoscale DiscussionSPCDimmit, Duval, Jim Hogg, La Salle, Webb, Zapata90 min
May 19, 3:32 AM CDTMesoscale DiscussionSPCBrooks, Dimmit, Duval, Hidalgo, Jim Hogg, Jim Wells and 5 more118 min
May 19, 7:09 AM CDTMesoscale DiscussionSPCHidalgo, Jim Hogg, Starr96 min
May 19, 8:46 AM CDTMesoscale DiscussionSPCBrooks, Cameron, Hidalgo, Kenedy, Willacy89 min
May 19, 2:10 PM CDTMesoscale DiscussionSPCCallahan, Coke, Coleman, Concho, Crane, Crockett and 24 more3 hr
May 19, 6:06 PM CDTMesoscale DiscussionSPCCrane, Crockett, Ector, Glasscock, Irion, Midland and 6 more84 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; radar from the NEXRAD Level II archive.