

000 

WWUS20 KWNS 312324

SEL7

SPC WW 312324

KSZ000-OKZ000-010600-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 407

NWS STORM PREDICTION CENTER NORMAN OK

625 PM CDT SAT MAY 31 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       EXTREME SOUTH CENTRAL AND SOUTHEAST KANSAS

       NORTH CENTRAL AND NORTHEAST OKLAHOMA



EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 625 PM

UNTIL 100 AM CDT.



TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 50 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 40 MILES SOUTH OF ALVA

OKLAHOMA TO 45 MILES SOUTH SOUTHEAST OF CHANUTE KANSAS.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU7).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



OTHER WATCH INFORMATION...CONTINUE...WW 403...WW 404...WW

405...WW 406...



DISCUSSION...VISIBLE IMAGERY SUGGESTS THAT DEEPENING CUMULUS

CONVECTION ALONG AND N OF AN OUTFLOW BOUNDARY WILL LIKELY DEVELOP

INTO THUNDERSTORMS BY ABOUT 00Z.  STRONG INSTABILITY WILL FEED THIS

CONVECTION FROM THE S...AND VERTICAL SHEAR IS FAVORABLE FOR

SUPERCELLS.  BOUNDARY LAYER DEWPOINTS AROUND 70 F AND SOMEWHAT

ENHANCED SRH ALONG THE BOUNDARY COULD ALSO SUPPORT A COUPLE OF

TORNADOES THIS EVENING.  OTHERWISE...VERY LARGE HAIL WILL BE AN

INITIAL THREAT...WITH SOME POTENTIAL FOR UPSCALE GROWTH INTO A SMALL

MCS ACROSS SE KS/NE OK WITH AN INCREASING THREAT FOR DAMAGING WINDS.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

550. MEAN STORM MOTION VECTOR 27020.





...THOMPSON

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