

495 

WWUS20 KWNS 300159

SEL7

SPC WW 300159

OKZ000-TXZ000-300800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 637

NWS STORM PREDICTION CENTER NORMAN OK

900 PM CDT WED JUL 29 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       MUCH OF CENTRAL AND WESTERN OKLAHOMA

       PARTS OF NORTHWEST TEXAS



EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 900 PM

UNTIL 300 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 100

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 35 MILES EAST OF

CHANDLER OKLAHOMA TO 45 MILES WEST SOUTHWEST OF CLINTON OKLAHOMA.

 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 635...WW 636...



DISCUSSION...THUNDERSTORMS EXPECTED TO INCREASE IN NUMBER AND

INTENSITY ACROSS THE WATCH AREA AS AIR MASS MDTLY UNSTABLE WITH

LITTLE REMAINING CINH. WITH 30-35KT OF SHEAR AND STEEP MID LEVEL

LAPSE RATES LARGE HAIL AND LOCAL DAMAGING WINDS WILL BE THE THREAT.

MORE ORGANIZED/DEVELOPING MCS TX PANHANDLE WILL ALSO BE A CONCERN AS

IT MOVES E/SEWD INTO SWRN OK/NWRN TX.



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 29020.





...HALES

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