

236 

WWUS20 KWNS 232252

SEL3

SPC WW 232252

IAZ000-ILZ000-MOZ000-240400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 503

NWS STORM PREDICTION CENTER NORMAN OK

555 PM CDT TUE JUN 23 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHEAST IOWA

       EXTREME WEST CENTRAL ILLINOIS

       NORTHERN MISSOURI



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 555 PM UNTIL

1100 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 55

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 45 MILES NORTH OF

SAINT JOSEPH MISSOURI TO 25 MILES EAST OF BURLINGTON IOWA.  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 497...WW 498...WW

499...WW 500...WW 501...WW 502...



DISCUSSION...THE LINEAR MCS ACROSS S/SE IA WILL CONTINUE TO DEVELOP

SEWD/SWD THE NEXT FEW HOURS...INTO A STRONGLY UNSTABLE ENVIRONMENT

OVER SRN IA/NRN MO.  THE STRONGER STORMS IN THE CLUSTER WILL

CONTINUE TO BE CAPABLE OF PRODUCING DAMAGING DOWNBURST WINDS AND

ISOLATED LARGE HAIL.



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 32020.





...THOMPSON

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