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875 

WWUS20 KWNS 180805

SEL8

SPC WW 180805

IAZ000-ILZ000-MOZ000-181400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 488

NWS STORM PREDICTION CENTER NORMAN OK

305 AM CDT SUN JUL 18 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EXTREME SOUTHEAST IOWA

       EXTREME WEST CENTRAL ILLINOIS

       NORTHERN MISSOURI



EFFECTIVE THIS SUNDAY MORNING FROM 305 AM UNTIL 900 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 40

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

OF LAMONI IOWA TO 25 MILES SOUTH SOUTHEAST OF BURLINGTON IOWA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU8).



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...



DISCUSSION...MERGING STORM CLUSTERS WILL CONTINUE TO SURGE SEWD FROM

IA INTO NRN MO THROUGH THE MORNING HOURS.  THIS CONVECTION WILL BE

SUPPORTED BY A CORRIDOR OF STRONG INSTABILITY AND MID-UPPER 70S

DEWPOINTS...AND DAMAGING WINDS WILL BE POSSIBLE WITH EMBEDDED BOW

ECHO STRUCTURES.



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 31030.





...THOMPSON

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