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WWUS20 KWNS 070155

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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 59

NWS STORM PREDICTION CENTER NORMAN OK

855 PM CDT TUE APR 6 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       LARGE PART OF CENTRAL AND EASTERN OKLAHOMA



EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 855 PM

UNTIL 400 AM CDT.



HAIL TO 2.5 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 20 MILES NORTHEAST OF

BARTLESVILLE OKLAHOMA TO 65 MILES SOUTH SOUTHEAST OF CHANDLER

OKLAHOMA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 56...WW 57...WW 58...



DISCUSSION...THUNDERSTORMS EXPECTED TO INCREASE IN NUMBER AND

INTENSITY ACROSS THE WATCH AS COLD FRONT OVERTAKES THE N/S DRY LINE

THRU WRN PORTION OF AREA.  WITH MLCAPES TO 1500 J/KG...STEEP MID

LEVEL LAPSE RATES AND 50-60 KT OF SHEAR...SEVERE THUNDERSTORMS ARE

LIKELY.  PRIMARY THREAT WILL BE LARGE HAIL WITH DAMAGING WINDS ALSO

POSSIBLE IN STRONGEST STORMS GIVEN THE STRENGTH OF STEERING FLOW AND

STEEP LAPSE RATES.



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

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 24030.





...HALES

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