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000 

WWUS20 KWNS 311935

SEL3

SPC WW 311935

ARZ000-OKZ000-010200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 923

NWS STORM PREDICTION CENTER NORMAN OK

235 PM CDT FRI OCT 31 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF WESTERN ARKANSAS

       PARTS OF EASTERN OKLAHOMA



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 235 PM UNTIL 900

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 50

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 25 MILES WEST OF

POTEAU OKLAHOMA TO 40 MILES EAST SOUTHEAST OF RUSSELLVILLE

ARKANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).



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...HEATING HAD REMOVED MUCH OF CINH WRN AR/ERN OK WITH

MLCAPES TO 1000 J/KG THIS AREA.  WITH SMALL UPPER LOW DROPPING SSEWD

FROM SWRN MO...LARGE SCALE ASCENT AND FAVORABLE SHEAR PROFILES

SUPPORTS DEVELOPMENT OF SURFACE  BASED THUNDERSTORMS ACROSS THE

WATCH.  WITH STEEP MID LEVEL LAPSE RATES AND COLD AIR ALOFT...LARGE

HAIL WILL BE PRIMARY THREAT WITH THE STRONGEST STORMS.



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 450. MEAN STORM

MOTION VECTOR 27025.





...HALES

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