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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 289

NWS STORM PREDICTION CENTER NORMAN OK

905 AM CDT THU MAY 12 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTH-CENTRAL AND SOUTHEAST TEXAS

       COASTAL WATERS



EFFECTIVE THIS THURSDAY MORNING AND AFTERNOON FROM 905 AM UNTIL

300 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 110

STATUTE MILES EITHER SIDE OF A LINE FROM 40 MILES SOUTHWEST OF

STEPHENVILLE TEXAS TO 20 MILES SOUTH SOUTHEAST OF HOUSTON TEXAS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 288...



DISCUSSION...MATURE FORWARD PROPAGATING MCS HAS DEVELOPED COMMA-HEAD

STRUCTURE ON ITS NORTHERN EXTENT AND SHOULD CONTINUE TO DEVELOP EAST

INTO INCREASINGLY UNSTABLE AIRMASS ACROSS PARTS OF NRN AND ERN TX

THROUGH THE MORNING. DEEP LAYER WIND FIELDS IN THE BASE OF THE LARGE

SCALE TROUGH TRANSITIONING EWD ACROSS THE PLAINS SHOULD CONTINUE TO

SUPPORT THIS CONVECTION WITH LARGE SCALE ASCENT CONTRIBUTING TO

ADDITIONAL DEVELOPMENT AHEAD OF THE SQUALL LINE. IN THE NRN AREAS OF

THE WATCH...HAIL WILL BE LIKELY INITIALLY. HOWEVER...WIND DAMAGE

POTENTIAL SHOULD ALSO INCREASE AS BOUNDARY LAYER UNDERGOES GRADUAL

WARMING AND SURFACE-BASED INHIBITION IS ELIMINATED.



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 25040.





...CARBIN

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