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URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 391

NWS STORM PREDICTION CENTER NORMAN OK

130 AM CDT WED JUN 23 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       EASTERN IOWA

       NORTHWEST ILLINOIS

       FAR SOUTHEAST MINNESOTA

       SOUTHWEST WISCONSIN



EFFECTIVE THIS WEDNESDAY MORNING FROM 130 AM UNTIL 900 AM CDT.



TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 25 MILES NORTH OF WATERLOO

IOWA TO 50 MILES SOUTHEAST OF LONEROCK WISCONSIN.  FOR A COMPLETE

DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE

(WOUS64 KWNS WOU1).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



OTHER WATCH INFORMATION...CONTINUE...WW 387...WW 388...WW

389...WW 390...



DISCUSSION...TSTMS/SUPERCELLS EXPECTED TO PERSIST AND SPREAD EWD

ALONG DIFFUSE W/E WARM FRONT OVER NE IA/EXTREME NW IL AS THE

BOUNDARY MOVES SLOWLY N LATER THIS MORNING.  AVAILABILITY OF VERY

RICH BOUNDARY LAYER MOISTURE...LOW LCLS...AND INCREASING 700-500 MB

FLOW ASSOCIATED WITH UPSTREAM JET STREAK OVER NEB WILL CREATE

ENVIRONMENT SUPPORTIVE OF SUPERCELLS.  GIVEN THE ABOVE SETUP...AN

ATTENDANT THREAT FOR TORNADOES MAY DEVELOP...DESPITE EXISTING

COMPLEX STORM MODE AND LIKELIHOOD FOR STORM INTERACTIONS.



AVIATION...TORNADOES AND 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

500. MEAN STORM MOTION VECTOR 26035.





...CORFIDI

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