

226 

WWUS20 KWNS 180913

SEL7

SPC WW 180913

ILZ000-181500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 457

NWS STORM PREDICTION CENTER NORMAN OK

415 AM CDT THU JUN 18 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL ILLINOIS



EFFECTIVE THIS THURSDAY MORNING FROM 415 AM UNTIL 1000 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 55

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 40 MILES WEST

SOUTHWEST OF PEORIA ILLINOIS TO 30 MILES SOUTH OF DANVILLE

ILLINOIS.  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 454...WW 455...WW 456...



DISCUSSION...MULTIPLE CLUSTERS OF INTENSE THUNDERSTORMS OVER

SOUTHEAST IA AND WESTERN IL WILL LIKELY MAINTAIN INTENSITY AS IT

TRACKS ACROSS CENTRAL IL.  STORMS ARE ALONG THE GRADIENT OF A VERY

UNSTABLE AIRMASS...WITH ACTIVITY MOVING AT OVER 40 KNOTS.  DAMAGING

WINDS APPEAR TO BE THE MAIN THREAT.



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 500. MEAN STORM

MOTION VECTOR 26040.





...HART

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