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448 

WWUS20 KWNS 080511

SEL4

SPC WW 080511

KSZ000-OKZ000-081300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 264

NWS STORM PREDICTION CENTER NORMAN OK

1205 AM CDT FRI MAY 8 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       A LARGE PART OF KANSAS

       NORTHERN OKLAHOMA



EFFECTIVE THIS FRIDAY MORNING FROM 1205 AM UNTIL 800 AM CDT.



...THIS IS A PARTICULARLY DANGEROUS SITUATION...



EXTREMELY DAMAGING THUNDERSTORM WIND GUSTS TO 80 MPH...LARGE HAIL

TO 3 INCHES IN DIAMETER...AND DANGEROUS LIGHTNING ARE POSSIBLE IN

THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 80

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES WEST OF

GARDEN CITY KANSAS TO 25 MILES EAST SOUTHEAST OF CHANUTE KANSAS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 260...WW 261...WW

262...WW 263...



DISCUSSION...TSTMS/SUPERCELLS EXPECTED TO FORM IN THE NEXT 1-2 HOURS

IN WAA AREA ALONG SRN FRINGE OF UPR DISTURBANCE AMPLIFYING ESE

ACROSS THE CNTRL HI PLNS.  COMBINATION OF INCREASINGLY RICH MOIST

INFLOW...DEEP EML...AND SEASONABLY STRONG/LARGELY UNIDIRECTIONAL WLY

MID/UPR LVL FLOW SHOULD SUPPORT RAPID STORM INTENSIFICATION ONCE

CELLS FORM.  ALTHOUGH A RISK FOR ISOLD TORNADOES WILL EXIST DURING

EARLY STAGES OF STORM DEVELOPMENT...SFC-BASED CIN AND LIKELIHOOD FOR

NUMEROUS STORM INTERACTIONS ONCE ACTIVITY DEVELOPS SUGGEST THAT MAIN

SVR THREAT EARLY-ON WILL BE VERY LARGE HAIL.  SIZABLE DCAPE SHOULD

FOSTER SUBSEQUENT EVOLUTION INTO A FORWARD-PROPGATING MCS...WITH

FAIRLY WIDESPREAD DMGG WIND/HAIL.



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 550. MEAN STORM

MOTION VECTOR 29035.





...CORFIDI

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