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030 

WWUS20 KWNS 281922

SEL6

SPC WW 281922

IAZ000-ILZ000-INZ000-290000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 546

NWS STORM PREDICTION CENTER NORMAN OK

225 PM CDT WED JUL 28 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF EASTERN IOWA

       PARTS OF NORTHERN ILLINOIS

       SMALL PART OF NORTHWEST INDIANA



EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 225 PM UNTIL

700 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 SOUTHEAST

OF VALPARAISO INDIANA TO 20 MILES WEST SOUTHWEST OF BURLINGTON

IOWA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



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 545...



DISCUSSION...WITH A VERY UNSTABLE AIR MASS THE COLD FRONT DROPPING

SEWD ACROSS THE WATCH WILL INITIATE STRONG/SEVERE THUNDERSTORMS.

PRIMARY THREAT WILL BE DAMAGING WINDS AS STORMS DEVELOP INTO

CLUSTERS...SHORT LINES FORMING COLD POOLS.



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 27025.





...HALES

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