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034 

WWUS20 KWNS 040153

SEL6

SPC WW 040153

ILZ000-INZ000-WIZ000-LMZ000-040800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 86

NWS STORM PREDICTION CENTER NORMAN OK

855 PM CDT SUN APR 3 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN ILLINOIS

       NORTHWEST INDIANA

       SOUTHEAST WISCONSIN

       LAKE MICHIGAN



EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 855 PM UNTIL

300 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 55

STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH

NORTHWEST OF MILWAUKEE WISCONSIN TO 20 MILES SOUTHEAST OF

MARSEILLES ILLINOIS.  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.



OTHER WATCH INFORMATION...CONTINUE...WW 82...WW 83...WW 84...WW

85...



DISCUSSION...CLUSTERS OF STRONG/SEVERE THUNDERSTORMS OVER NORTHWEST

IL/SOUTHWEST WI WILL TRACK EASTWARD ALONG A SURFACE WARM FRONT

TOWARD THE MILWAUKEE/CHICAGO AREAS OVERNIGHT.  LARGE HAIL WILL BE

THE MAIN THREAT...ALTHOUGH ISOLATED DAMAGING WIND GUSTS WILL ALSO BE

POSSIBLE WITH STORMS TRACKING ALONG AND SOUTH OF THE FRONT.



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 24035.





...HART

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