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544 

WWUS20 KWNS 111817

SEL0

SPC WW 111817

OKZ000-TXZ000-120000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 280

NWS STORM PREDICTION CENTER NORMAN OK

120 PM CDT WED MAY 11 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL AND EASTERN OKLAHOMA

       EXTREME NORTH CENTRAL TEXAS



EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 120 PM UNTIL

700 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 95

STATUTE MILES EAST AND WEST OF A LINE FROM 10 MILES NORTH

NORTHEAST OF BARTLESVILLE OKLAHOMA TO 45 MILES WEST SOUTHWEST OF

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

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



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 278...WW 279...



DISCUSSION...PRE-FRONTAL CONVECTION OVER CNTRL OK INTO N-CNTRL TX

WILL LIKELY DEVELOP EWD WITH TIME. MODERATE INSTABILITY...STEEP

LAPSE RATES AND VERTICAL SHEAR FROM 35-45 KT WILL SUPPORT POTENTIAL

FOR BOTH MULTICELL AND POSSIBLY SOME SUPERCELL STRUCTURES WITH

ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS THE MAIN THREATS.



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 24035.





...DIAL

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