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353 

WWUS20 KWNS 121953

SEL2

SPC WW 121953

KSZ000-130200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 772

NWS STORM PREDICTION CENTER NORMAN OK

250 PM CDT FRI AUG 12 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST AND SOUTH-CENTRAL KANSAS



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 250 PM UNTIL 900

PM CDT.



HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 20 MILES WEST OF

GARDEN CITY KANSAS TO 50 MILES EAST NORTHEAST OF WICHITA 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.



OTHER WATCH INFORMATION...CONTINUE...WW 771...



DISCUSSION...EXTREME INSTABILITY HAS DEVELOPED WITH HEATING OF THE

DAY ALONG OUTFLOW BOUNDARY ACROSS CNTRL AND SWRN KS. EXPECT NEW

STORM INITIATION TO OCCUR ALONG/NEAR THE BOUNDARY OVER THE NEXT FEW

HOURS. WEAK LOW LEVEL FLOW TOPPED BY MODEST 25-3O KT WNWLY FLOW

ALOFT WILL RESULT IN SHEAR PROFILES SUPPORTIVE OF UPDRAFT ROTATION

AND PERSISTENCE. MAGNITUDE OF LAPSE RATES AND RESULTING

INSTABILITY...WHEN COUPLED WITH KINEMATIC REGIME...SHOULD SUPPORT

THE PRODUCTION OF VERY LARGE HAIL. ADDITIONALLY...HIGH DCAPE VALUES

IN THE BOUNDARY LAYER WILL CONTRIBUTE TO POTENTIALLY DESTRUCTIVE

DOWNDRAFTS. EVENTUALLY...UPSCALE GROWTH THROUGH STORM MERGERS MAY

SUPPORT A FORWARD PROPAGATING MCS WITH WIND AND HAIL SPREADING EAST

AND SOUTH THROUGH THE EVENING.



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

TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

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

MOTION VECTOR 29025.





...CARBIN

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