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WWUS20 KWNS 082004

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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 758

NWS STORM PREDICTION CENTER NORMAN OK

305 PM CDT THU OCT 8 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST INTO NORTHEAST OKLAHOMA

       NORTHWEST TEXAS



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 305 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 EAST AND WEST OF A LINE FROM 55 MILES SOUTH

SOUTHWEST OF WICHITA FALLS TEXAS TO 5 MILES NORTH NORTHWEST OF

TULSA OKLAHOMA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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...THUNDERSTORMS WILL CONTINUE TO INCREASE IN COVERAGE AND

INTENSITY ACROSS THIS REGION THROUGH THE EVENING AHEAD OF STRONG

SURFACE COLD FRONT.  AIR MASS IS VERY MOIST AND MODERATELY UNSTABLE

AHEAD OF THE FRONT...WITH EFFECTIVE SHEAR OF 40-50 KT.  ACTIVITY MAY

EVOLVE AS SUPERCELLS...WITH EVENTUAL EVOLUTION INTO ONE OR MORE

LINES OF STORMS ALONG AND AHEAD OF THE FRONT THIS EVENING.  INITIAL

ACTIVITY BEHIND LEADING WIND SHIFT SHOULD REMAIN SLIGHTLY ELEVATED

WITH PRIMARY THREAT OF LARGE HAIL...ALTHOUGH STORMS ROOTING INTO THE

BOUNDARY LAYER AHEAD OF THE FRONT WILL BE CAPABLE OF WIND DAMAGE.



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 400. MEAN STORM

MOTION VECTOR 23035.





...EVANS

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