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WWUS20 KWNS 260653

SEL2

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LAZ000-TXZ000-CWZ000-261200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 212

NWS STORM PREDICTION CENTER NORMAN OK

155 AM CDT TUE APR 26 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST LOUISIANA

       SOUTHEAST TEXAS

       COASTAL WATERS



EFFECTIVE THIS TUESDAY MORNING FROM 155 AM UNTIL 700 AM 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 50

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 45 MILES NORTH OF

HOUSTON TEXAS TO 10 MILES EAST OF LAFAYETTE LOUISIANA.  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.



OTHER WATCH INFORMATION...THIS SEVERE THUNDERSTORM WATCH REPLACES

TORNADO WATCH NUMBER 210. WATCH NUMBER 210 WILL NOT BE IN EFFECT

AFTER 155 AM CDT. CONTINUE...WW 207...WW 211...



DISCUSSION...BACK-BUILDING LINE OF SEVERE STORMS WILL LIKELY PERSIST

FOR SEVERAL MORE HOURS ACROSS SE TX/SW LA...WITH CONVECTION

MAINTAINED BY 40 KT SSWLY LLJ AND LOW 70S BOUNDARY LAYER DEWPOINTS.

THE COMBINATION OF EFFECTIVE BULK SHEAR IN EXCESS OF 40 KT AND

MUCAPE AOA 2500 J/KG WILL MAINTAIN A RISK FOR EMBEDDED

SUPERCELLS...AS WELL AS BOWING SEGMENTS...WITH AN ACCOMPANYING RISK

FOR 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 600. MEAN STORM

MOTION VECTOR 29020.





...THOMPSON

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