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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

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