Severe Thunderstorm Watch 270

Issued

May 10, 2012, 5:42 AM CDT (10:42 UTC)

Expired

May 10, 2012, 1:00 PM CDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Laughlin AFB radar (KDFX), 90 km from the middle of the area, began a volume at 10:45 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.

Two or more tornadoes

20%

One or more EF2 to EF5 tornadoes

10%

Ten or more severe wind reports

30%

One or more gusts of 65 knots or more

20%

Ten or more severe hail reports

70%

One or more hailstones of 2 inches or more

30%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 772May 10, 5:27 AM CDT
• Mesoscale Discussion 773May 10, 9:51 AM CDT
• Mesoscale Discussion 774May 10, 11:52 AM CDT

258 
WWUS20 KWNS 101048
SEL0
SPC WW 101048
TXZ000-CWZ000-101800-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 270
NWS STORM PREDICTION CENTER NORMAN OK
545 AM CDT THU MAY 10 2012

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

       SOUTH CENTRAL AND DEEP SOUTH TEXAS
       COASTAL WATERS

EFFECTIVE THIS THURSDAY MORNING AND AFTERNOON FROM 545 AM UNTIL
100 PM CDT.

HAIL TO 2 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 70
STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES WEST
NORTHWEST OF JUNCTION TEXAS TO 5 MILES WEST SOUTHWEST OF
BROWNSVILLE TEXAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).

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...ELEVATED TSTMS...INCLUDING A FEW SUPERCELLS... EXPECTED
TO INCREASE IN COVERAGE OVER THE LWR RIO GRANDE VLY OF TX THROUGH
MIDDAY AS WAA...LOW LVL MOISTURE TRANSPORT...AND UPR DIVERGENCE
INCREASE DOWNSTREAM FROM UPR LOW NOW APPROACHING FROM N CNTRL
MEXICO.  DEEP WIND PROFILES...ALREADY ADEQUATE FOR SUPERCELLS...WILL
STRENGTHEN LATER THIS MORNING.  COUPLED WITH QUALITY OF MOIST INFLOW
/PW 1.25-1.75 INCHES/ AND THE LIKELIHOOD THAT UPDRAFTS WILL BECOME
MORE NEARLY SFC-BASED WITH TIME...SRN AND PERHAPS CNTRL PARTS OF THE
WATCH MAY REQUIRE UPGRADE TO TORNADO LATER THIS MORNING.

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 24020.


...CORFIDI

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

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.