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122 

WWUS20 KWNS 220250

SEL4

SPC WW 220250

IAZ000-ILZ000-INZ000-MIZ000-MOZ000-LMZ000-221000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 374

NWS STORM PREDICTION CENTER NORMAN OK

950 PM CDT MON JUN 21 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       FAR SOUTHEASTERN IOWA

       ILLINOIS

       NORTHERN AND CENTRAL INDIANA

       FAR SOUTHWESTERN MICHIGAN

       EXTREME NORTHEAST MISSOURI

       LAKE MICHIGAN



EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 950 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 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 60 MILES WEST

NORTHWEST OF QUINCY ILLINOIS TO 35 MILES NORTH NORTHEAST OF

INDIANAPOLIS INDIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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...THIS SEVERE THUNDERSTORM WATCH REPLACES

TORNADO WATCH NUMBER 369. WATCH NUMBER 369 WILL NOT BE IN EFFECT

AFTER 950 PM CDT. CONTINUE...WW 367...WW 370...WW 371...WW

372...WW 373...



DISCUSSION...AS SHORTWAVE TROUGH PROGRESSES EWD THROUGH THE GREAT

LAKES OVERNIGHT...STORMS ARE EXPECTED TO SPREAD EWD THROUGH THE

WATCH AREA. THE MAIN THREAT WILL BE HAIL...THOUGH IF STORMS CAN

ORGANIZE INTO LINE SEGMENTS...WIND DAMAGE WOULD BECOME THE GREATER

THREAT.



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 550. MEAN STORM

MOTION VECTOR 27025.





...IMY

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