

000 

WWUS20 KWNS 260456

SEL3

SPC WW 260456

ILZ000-INZ000-LMZ000-261000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 373

NWS STORM PREDICTION CENTER NORMAN OK

1155 PM CDT SUN MAY 25 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN ILLINOIS

       NORTHWEST INDIANA

       LAKE MICHIGAN



EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 1155 PM UNTIL

500 AM CDT.



HAIL TO 1.5 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 80

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES WEST

NORTHWEST OF BENTON HARBOR MICHIGAN TO 40 MILES SOUTHWEST OF

PEORIA ILLINOIS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).



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 365...WW 366...WW

368...WW 370...WW 371...WW 372...



DISCUSSION...W-W BAND OF TSTMS IN NRN IL EXPECTED TO CONTINUE SLOWLY

SAGGING SWD ...WHILE INDIVIDUAL STORMS MOVE RAPIDLY EWD ALONG.

FARTHER W...N-S BOW ECHO IN ERN IA EXPECTED T0 CONTINUE E ACROSS NRN

IL.  ALTHOUGH AIR MASS IS NOT AS UNSTABLE OVER NERN IL AS IT IS

FARTHER W...BOUNDARY LAYER WILL CONTINUE TO RECOVER FROM THE

WSW...GIVEN CURRENT VWP DATA.  COMBINATION OF EXISTING UPSTREAM

STORMS...AND CONTINUING PRESENCE OF MDT TO STG WSWLY MEAN

FLOW...SUGGEST POSSIBILITY FOR DMGG WIND GUSTS AND PERHAPS AN ISOLD

QLCS TORNADO OR TWO EWD INTO WW ...DESPITE UNFAVORABLE TIME OF DAY



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 27040.





...CORFIDI

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