

000 

WWUS20 KWNS 242303

SEL6

SPC WW 242303

KSZ000-NEZ000-250600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 226

NWS STORM PREDICTION CENTER NORMAN OK

605 PM CDT THU APR 24 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHWEST KANSAS

       SOUTHWEST NEBRASKA



EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 605 PM

UNTIL 100 AM 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 70

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 35 MILES SOUTHWEST

OF IMPERIAL NEBRASKA TO 60 MILES NORTH NORTHEAST OF HILL CITY

KANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



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.



DISCUSSION...CONVECTION WILL INCREASE IN COVERAGE/INTENSITY THROUGH

THE EVENING AS A MID LEVEL TROUGH AND ASSOCIATED SURFACE LOW MOVE

EWD FROM CO TO KS/NEB.  STEEP LAPSE RATES AND 0-6 KM BULK SHEAR IN

EXCESS OF 50 KT WILL SUPPORT ORGANIZED SEVERE STORMS...INCLUDING

SUPERCELLS...CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS.  AN

ISOLATED TORNADO CANNOT BE RULED OUT...BUT RELATIVELY WEAK LOW-LEVEL

SHEAR AND MODEST BOUNDARY LAYER MOISTURE SUGGEST THIS THREAT IS

LIMITED THROUGH MUCH OF THE EVENING.



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 26020.





...THOMPSON

