

417 

WWUS20 KWNS 242145

SEL0

SPC WW 242145

IAZ000-MNZ000-WIZ000-250400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 180

NWS STORM PREDICTION CENTER NORMAN OK

445 PM CDT FRI APR 24 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST THROUGH NORTHEAST IOWA

       SOUTHEAST MINNESOTA

       CENTRAL INTO NORTHERN WISCONSIN



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 445 PM UNTIL

1100 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 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES NORTH

NORTHWEST OF SHENANDOAH IOWA TO 15 MILES SOUTHEAST OF RHINELANDER

WISCONSIN.  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.



DISCUSSION...SEVERE THUNDERSTORMS WILL CONTINUE TO INCREASE ALONG

AND AHEAD OF STRONG SURFACE COLD FRONT PUSHING SEWD ACROSS WW

THROUGH THE EVENING.  VERY WARM SURFACE TEMPERATURES AND INCREASING

ASCENT WILL WEAKEN CAP AND STEEPEN LAPSE RATES SUPPORTING THREAT OF

HAIL WITH THE STRONGER STORMS.  IN ADDITION...SHEAR WILL BE

SUFFICIENT FOR SUPERCELLS.  ISOLATED DAMAGING WINDS AND POSSIBLY A

TORNADO ARE ALSO EXPECTED.



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 25030.





...EVANS

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