Alert archive / Texas / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 182

April 16, 20124 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Apr 16, 2012, 3:28 PM CDT for 4 counties in Texas. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Apr 16, 2012, 3:28 PM CDT (20:28 UTC)
Expired
Apr 16, 2012, 7:00 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt

Counties Cameron County, TX, Hidalgo County, TX, Kenedy County, TX, Willacy County, TX

The radar

The Brownsville radar (KBRO), 75 km from the middle of the area, began a volume at 20:31 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
5%
Ten or more severe wind reports
20%
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

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

IssuedProductOfficeCountiesLasted
Apr 16, 3:32 PM CDTTornado WarningBROKenedy, Willacy28 min
Apr 16, 4:01 PM CDTSevere Thunderstorm WarningBROKenedy, Willacy44 min
Apr 16, 4:06 PM CDTSevere Thunderstorm WarningBROCameron, Willacy39 min
Apr 16, 4:16 PM CDTSevere Thunderstorm WarningBROWillacy29 min
Apr 16, 4:25 PM CDTTornado WarningBROCameron35 min
Apr 16, 4:56 PM CDTTornado WarningBROCameron34 min
Apr 16, 5:28 PM CDTSevere Thunderstorm WarningBROCameron32 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

Brownsville Intl, TX (KBRO), launched 12:00Z, 8.5 hours before the alert went out and 78 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, Brownsville Intl, TX at 12:00Z on 2012-04-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2823 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, Brownsville Intl, TX at 12:00Z on 2012-04-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 125 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
2823 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
536 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
125 m²/s²
0-3 km storm-relative helicity
249 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.

201 
WWUS20 KWNS 162022
SEL2
SPC WW 162022
TXZ000-CWZ000-170000-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 182
NWS STORM PREDICTION CENTER NORMAN OK
325 PM CDT MON APR 16 2012

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

       EXTREME SOUTHERN TEXAS
       COASTAL WATERS

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 325 PM UNTIL 700
PM 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 35
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 20 MILES NORTHWEST
OF MCALLEN TEXAS TO 40 MILES NORTHEAST OF BROWNSVILLE TEXAS.  FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU2).

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.

DISCUSSION...STRONG/SEVERE STORMS ARE CONTINUING TO DEVELOP ALONG AN
OUTFLOW BOUNDARY MOVING SLOWLY SWD ACROSS EXTREME SRN TX.  AIR MASS
IS UNSTABLE WITH MLCAPE TO 2000 J/KG...AND VEERING WINDS WITH HEIGHT
ON KBRO VAD INDICATE SUFFICIENT VERTICAL SHEAR FOR ORGANIZED
MULTI-CELL AND BRIEF SUPERCELL STRUCTURES.

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 25015.


...WEISS

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 16, 5:50 AM CDTMesoscale DiscussionSPCAransas, Calhoun, Nueces, Refugio, San Patricio55 min
Apr 16, 8:07 AM CDTSevere Thunderstorm WatchSPCAransas, Bee, Brooks, Calhoun, Cameron, Goliad and 10 more7 hr
Apr 16, 12:06 PM CDTMesoscale DiscussionSPCAransas, Bee, Brooks, Calhoun, Cameron, DeWitt and 14 more84 min
Apr 16, 2:23 PM CDTMesoscale DiscussionSPCBrooks, Cameron, Hidalgo, Kenedy, Willacy67 min

Nearby

Severe Thunderstorm Watches in Texas, 2012Every 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.