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000 

WWUS20 KWNS 120259

SEL7

SPC WW 120259

IAZ000-MNZ000-WIZ000-121000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 587

NWS STORM PREDICTION CENTER NORMAN OK

1000 PM CDT SAT AUG 11 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEAST IOWA

       SOUTHEAST MINNESOTA

       CENTRAL AND SOUTHERN WISCONSIN



EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 1000 PM

UNTIL 500 AM CDT.



HAIL TO 2 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 50

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 35 MILES WEST OF LA

CROSSE WISCONSIN TO 45 MILES NORTHEAST OF MADISON WISCONSIN.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU7).



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 586...



DISCUSSION...CLUSTER OF INTENSE THUNDERSTORMS OVER SOUTHEAST MN AND

WESTERN WI WILL SPREAD EAST-SOUTHEASTWARD INTO SOUTHERN WI DURING

THE NEXT SEVERAL HOURS.  VERY HIGH CAPE VALUES...COUPLED WITH

SUFFICIENT VERTICAL SHEAR AND INCREASING MESOSCALE ORGANIZATION OF

THUNDERSTORMS...SUGGEST A THREAT OF DAMAGING WINDS AND LARGE HAIL

FOR SEVERAL MORE HOURS.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 28035.





...HART

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