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805 

WWUS20 KWNS 232006

SEL7

SPC WW 232006

OKZ000-TXZ000-240300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 187

NWS STORM PREDICTION CENTER NORMAN OK

310 PM CDT SAT APR 23 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHERN OKLAHOMA

       NORTH CENTRAL TEXAS



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 310 PM UNTIL

1000 PM CDT.



HAIL TO 3 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 NORTH AND SOUTH OF A LINE FROM 65 MILES NORTH

NORTHWEST OF BROWNWOOD TEXAS TO 65 MILES NORTHEAST OF PARIS

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.



OTHER WATCH INFORMATION...CONTINUE...WW 186...



DISCUSSION...SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER

NORTH TX AND SOUTHERN OK WITHIN THEN NEXT COUPLE OF HOURS AS

CONTINUED HEATING WEAKENS THE CAP.  A VERY UNSTABLE AIR MASS IS

PRESENT WITH CAPE VALUES OF 3000+ J/KG.  SUFFICIENT VERTICAL SHEAR

WILL SUPPORT SUPERCELL STORMS...WITH VERY LARGE HAIL POSSIBLE FROM

THE STRONGER CELLS.  DAMAGING WINDS WILL ALSO BE POSSIBLE.



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

TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 25030.





...HART

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