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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 534

NWS STORM PREDICTION CENTER NORMAN OK

500 PM CDT TUE JUN 21 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST THROUGH CENTRAL TO NORTHEAST TEXAS



EFFECTIVE THIS TUESDAY AFTERNOON AND WEDNESDAY MORNING FROM 500

PM UNTIL 100 AM CDT.



HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 75

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 65

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 50 MILES WEST OF

FORT STOCKTON TEXAS TO 35 MILES EAST SOUTHEAST OF LONGVIEW TEXAS.

 FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 531...WW 532...WW 533...



DISCUSSION...TSTMS EXPECTED TO INCREASE MARKEDLY IN

COVERAGE/STRENGTH OVER CNTRL AND SW TX LATER THIS AFTN AND EVE AS

HEATING FURTHER ERODES CINH ON NRN FRINGE OF WARM/MOIST AIR MASS

LEFT UN-OVERTURNED BY LAST NIGHTS MCS.  OTHER STORMS EXPECTED TO

PROPAGATE GENERALLY SW FROM EXISTING STORM CLUSTER SW OF SHV.

DEGREE AND DISTRIBUTION OF SFC-BASED INSTABILITY...AND MODERATE DEEP

SHEAR WITH SIZABLE DIRECTIONAL COMPONENT SUGGEST LIKELIHOOD FOR

SUSTAINED STORMS AND A FEW SUPERCELLS WITH A THREAT FOR LARGE

HAIL...LOCALLY DMGG WIND...AND PERHAPS A TORNADO.  THE CNTRL AND W

TX STORMS MAY ORGANIZE INTO A COUPLE LOOSELY-ORGANIZED CLUSTERS THAT

PERSIST INTO THE NIGHT WITH A GRADUALLY DIMINISHING SVR THREAT.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600. MEAN STORM

MOTION VECTOR 30020.





...CORFIDI

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