Alert archive / Texas / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 276

May 13, 201210 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at May 13, 2012, 9:21 PM CDT for 10 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: May 13, 2012, 9:21 PM CDT (02:21 UTC)
Expired: May 14, 2012, 4:00 AM CDT
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

Counties Brewster County, TX, Crane County, TX, Culberson County, TX, Jeff Davis County, TX, Loving County, TX, Pecos County, TX, Reeves County, TX, Terrell County, TX, Ward County, TX, Winkler County, TX

The radar

The Midland/Odessa radar (KMAF), 159 km from the middle of the area, began a volume at 02:23 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: 5%
One or more EF2 to EF5 tornadoes: 2%
Ten or more severe wind reports: 40%
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: 10%
Six or more combined severe hail and wind reports: 70%

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
May 13, 10:16 PM CDT	Severe Thunderstorm Warning	MAF	Culberson, Loving, Reeves, Ward, Winkler	59 min
May 13, 11:16 PM CDT	Severe Thunderstorm Warning	MAF	Loving, Pecos, Reeves, Ward	59 min
May 14, 12:09 AM CDT	Severe Thunderstorm Warning	MAF	Pecos	66 min
May 14, 1:14 AM CDT	Severe Thunderstorm Warning	MAF	Pecos, Terrell	61 min
May 14, 2:17 AM CDT	Severe Thunderstorm Warning	MAF	Brewster, Terrell	58 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 00:00Z, 2.4 hours before the alert went out and 158 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: 2 J/kg
Mixed-layer CIN: -196 J/kg
Mixed-layer LCL: 2009 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 34 m²/s²
0-3 km storm-relative helicity: 219 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

396 
WWUS20 KWNS 140224
SEL6
SPC WW 140224
TXZ000-140900-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 276
NWS STORM PREDICTION CENTER NORMAN OK
925 PM CDT SUN MAY 13 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

       SOUTHWEST TEXAS

EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 925 PM UNTIL
400 AM CDT.

HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 75
STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES WEST
NORTHWEST OF WINK TEXAS TO 35 MILES SOUTH OF FORT STOCKTON TEXAS.
 FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU6).

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 275...

DISCUSSION...BAND OF STRONG/SEVERE STORMS IS MOVING SEWD FROM
EXTREME SERN NM TOWARD SW TX...IN ADVANCE OF A WELL-DEFINED SHORT
WAVE TROUGH MOVING SEWD TOWARD THE SRN ROCKIES.  AN AXIS OF STRONGER
WNWLY MID/UPPER LEVEL WINDS EXTENDS FROM SWRN NM INTO FAR SWRN
TX...PROVIDING ENHANCED LARGE SCALE ASCENT WITHIN THE LEFT EXIT
REGION OF THE UPPER JET.  EASTERLY LOW LEVEL WINDS EVIDENT ON MAF
RAOB AND VAD VEER SHARPLY WITH HEIGHT RESULTING IN FAVORABLE SHEAR
TO MAINTAIN ORGANIZED CONVECTIVE STRUCTURES INCLUDING SHORT BOWING
LINE SEGMENTS. THREAT FOR DAMAGING WINDS AND LARGE HAIL IS LIKELY TO
PERSIST INTO THE OVERNIGHT HOURS.

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 450. MEAN STORM
MOTION VECTOR 30025.


...WEISS

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 13, 9:14 PM CDT	Mesoscale Discussion	SPC	Culberson, Jeff Davis, Loving, Reeves, Ward	61 min
May 13, 11:37 PM CDT	Mesoscale Discussion	SPC	Crane, Culberson, Ector, Jeff Davis, Loving, Pecos and 3 more	53 min
May 14, 2:17 AM CDT	Mesoscale Discussion	SPC	Val Verde	118 min
May 14, 1:55 PM CDT	Mesoscale Discussion	SPC	Brewster, Concho, Crockett, Edwards, Irion, Jeff Davis and 9 more	3 hr
May 14, 2:55 PM CDT	Severe Thunderstorm Watch	SPC	Brewster, Jeff Davis, Pecos, Presidio, Reeves, Terrell	5 hr
May 14, 6:57 PM CDT	Mesoscale Discussion	SPC	Maverick	63 min

Nearby

Severe Thunderstorm Watches in Texas, 2012 Every severe thunderstorm watch in 2012

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.