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921 

WWUS20 KWNS 040435

SEL5

SPC WW 040435

ILZ000-041000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 235

NWS STORM PREDICTION CENTER NORMAN OK

1135 PM CDT THU MAY 3 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF CENTRAL AND NORTHERN ILLINOIS



EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 1135 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 45

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 70 MILES WEST OF

PEORIA ILLINOIS TO 25 MILES NORTH OF DANVILLE ILLINOIS.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU5).



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 232...SEVERE THUNDERSTORM WATCH NUMBER 233.

WATCH NUMBER 232 233 WILL NOT BE IN EFFECT AFTER 1135 PM CDT.

CONTINUE...WW 234...



DISCUSSION...MERGING STORMS AND UPSCALE GROWTH INTO AN MCS IS

UNDERWAY ACROSS NW IL...WITH AN EXPANDING COLD POOL AND INCREASING

RISK FOR DAMAGING GUSTS AS THE STORMS DEVELOP ESEWD/SEWD INTO THE

UNSTABLE WARM SECTOR.  THE STORMS WILL BE MAINTAINED BY A FEED OF

RICHER MOISTURE FROM THE SW...AND INSTABILITY REMAINS SUFFICIENT FOR

AT LEAST ISOLATED LARGE HAIL WITH THE STRONGER UPDRAFTS IN THE

CLUSTER.



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 30030.





...THOMPSON

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