Alert archive / Texas / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 232

June 1, 20218 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Jun 1, 2021, 12:09 AM CDT for 8 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jun 1, 2021, 12:09 AM CDT (05:09 UTC)
Expired: Jun 1, 2021, 6:00 AM CDT
In force: 6 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

Counties Brooks County, TX, Duval County, TX, Jim Hogg County, TX, Jim Wells County, TX, La Salle County, TX, McMullen County, TX, Webb County, TX, Zapata County, TX

The radar

The Corpus Christi radar (KCRP), 136 km from the middle of the area, began a volume at 05:09 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: 2%
Ten or more severe wind reports: 30%
One or more gusts of 65 knots or more: 10%
Ten or more severe hail reports: 20%
One or more hailstones of 2 inches or more: 5%
Six or more combined severe hail and wind reports: 60%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jun 1, 1:30 AM CDT	Severe Thunderstorm Warning	CRP	Webb	45 min
Jun 1, 2:05 AM CDT	Severe Thunderstorm Warning	CRP	La Salle, Webb	40 min
Jun 1, 2:33 AM CDT	Severe Thunderstorm Warning	CRP	La Salle, McMullen, Webb	57 min
Jun 1, 3:09 AM CDT	Severe Thunderstorm Warning	CRP	Duval, La Salle, McMullen, Webb	66 min
Jun 1, 4:38 AM CDT	Severe Thunderstorm Warning	BRO	Brooks, Jim Hogg	33 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

Corpus Christi, TX (KCRP), launched 00:00Z, 5.2 hours before the alert went out and 153 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 721 J/kg
Mixed-layer CIN: -121 J/kg
Mixed-layer LCL: 992 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: -12 m²/s²
0-3 km storm-relative helicity: 74 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

084 
WWUS20 KWNS 010505
SEL2  
SPC WW 010505
TXZ000-011100-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 232
NWS Storm Prediction Center Norman OK
1205 AM CDT Tue Jun 1 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  South Texas

* Effective this Tuesday morning from 1205 AM until 600 AM CDT.

* Primary threats include...
  Isolated damaging wind gusts to 70 mph possible
  Isolated large hail events to 1.5 inches in diameter possible
  A tornado or two possible

SUMMARY...A cluster of storms will continue southeastward along the
Rio Grande toward Deep South Texas overnight. Isolated damaging
winds and some severe hail are the primary concerns as storms
continue southeastward.

The severe thunderstorm watch area is approximately along and 45
statute miles east and west of a line from 10 miles north northwest
of Cotulla TX to 70 miles southeast of Laredo TX. 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.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 231...

AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 550. Mean storm motion vector
29025.

...Guyer

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 31, 7:17 PM CDT	Severe Thunderstorm Watch	SPC	Dimmit, Edwards, Kinney, Maverick, Real, Uvalde and 2 more	8 hr
May 31, 10:07 PM CDT	Mesoscale Discussion	SPC	Dimmit, Maverick, Zavala	83 min
Jun 1, 12:44 AM CDT	Mesoscale Discussion	SPC	Dimmit, La Salle, Maverick, Zavala	91 min
Jun 1, 2:50 AM CDT	Mesoscale Discussion	SPC	La Salle, McMullen, Webb	85 min
Jun 1, 2:14 PM CDT	Mesoscale Discussion	SPC	Dallam, Hartley	2 hr

Nearby

Severe Thunderstorm Watches in Texas, 2021 Every 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.