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WWUS20 KWNS 022031

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KSZ000-OKZ000-TXZ000-030300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 642

NWS STORM PREDICTION CENTER NORMAN OK

330 PM CDT THU SEP 2 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       LARGE PART OF SOUTHEAST KANSAS

       LARGE PART OF NORTHERN AND WESTERN OKLAHOMA

       PARTS OF NORTHWEST TEXAS



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 330 PM UNTIL

1000 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 80

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES SOUTH

SOUTHWEST OF CHILDRESS TEXAS TO 45 MILES EAST NORTHEAST OF

CHANUTE KANSAS.  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.



DISCUSSION...STRONG COLD FRONT WILL INITIATE THUNDERSTORMS AS IT

ENCOUNTERS AN INCREASINGLY UNSTABLE AND WEAKLY CAPPED AIR MASS.

WITH DCAPES TO 1500 J/KG AND MLCAPES AOA 2000 J/KG...DAMAGING WINDS

WILL BECOME INCREASING THREAT AS STORMS DEVELOP ALONG AND FRONT AS

IT CONTINUES SWD THRU THE WATCH.



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 550. MEAN STORM

MOTION VECTOR 30020.





...HALES

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