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446 

WWUS20 KWNS 181123

SEL9

SPC WW 181123

ILZ000-MOZ000-181800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 489

NWS STORM PREDICTION CENTER NORMAN OK

625 AM CDT SUN JUL 18 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL ILLINOIS

       EASTERN MISSOURI



EFFECTIVE THIS SUNDAY MORNING AND AFTERNOON FROM 625 AM UNTIL 100

PM 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 70

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

SOUTHEAST OF DECATUR ILLINOIS TO 10 MILES NORTH OF COLUMBIA

MISSOURI.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 487...WW 488...



DISCUSSION...WELL-DEVELOPED MCS WILL CONTINUE MOVING ESEWD/SEWD

ACROSS ERN MO INTO CENTRAL IL THROUGH THE MORNING.  MODERATE-STRONG

INSTABILITY REMAINS IN ADVANCE OF THIS CONVECTION...SUGGESTING THAT

IT WILL PERSIST GIVEN THE WELL-DEVELOPED COLD POOL AND MIDLEVEL MCV.

DAMAGING WINDS WILL CONTINUE TO BE THE MAIN SEVERE 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 30030.





...THOMPSON

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