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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 267

NWS STORM PREDICTION CENTER NORMAN OK

1100 AM CDT TUE MAY 8 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTH-CENTRAL TEXAS

       COASTAL WATERS



EFFECTIVE THIS TUESDAY MORNING AND EVENING FROM 1100 AM UNTIL 700

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 75

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTH OF

BEEVILLE TEXAS TO 65 MILES SOUTH SOUTHWEST OF ALICE TEXAS.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU7).



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...THE COMBINATION OF A COUPLED UPPER-LEVEL JET STREAK

STRUCTURE AND LOW-LEVEL UPLIFT ALONG FRONT IS EXPECTED TO CREATE A

FAVORABLE BACKGROUND ENVIRONMENT FOR SEVERE TSTMS ACROSS WATCH AREA

TODAY.  MODIFICATION OF 12Z CRP/BRO SOUNDINGS FOR ANTICIPATED

AFTERNOON CONDITIONS INDICATE A MODERATELY UNSTABLE AIR MASS WITH

MLCAPE VALUES OF 2000-2500 J/KG.  WHEN COMBINED WITH VERTICALLY

VEERING WIND PROFILES AND 40-50 KT OF DEEP-LAYER SHEAR...SETUP WILL

FAVOR SUPERCELLS AND BOWING STRUCTURES CAPABLE OF LARGE HAIL AND

DAMAGING WINDS.



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 500. MEAN STORM

MOTION VECTOR 28025.





...MEAD

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