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WWUS20 KWNS 030554

SEL5

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IAZ000-ILZ000-WIZ000-LMZ000-031300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 825

NWS STORM PREDICTION CENTER NORMAN OK

1250 AM CDT SAT SEP 3 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEAST IOWA

       FAR NORTHERN ILLINOIS

       SOUTHERN WISCONSIN

       LAKE MICHIGAN



EFFECTIVE THIS SATURDAY MORNING FROM 1250 AM UNTIL 800 AM CDT.



HAIL TO 1 INCH 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 35

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 70 MILES WEST OF

DUBUQUE IOWA TO 5 MILES NORTH NORTHEAST OF RACINE WISCONSIN.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU5).



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 824...



DISCUSSION...SIMILAR TO FRIDAY MORNING...SETUP AGAIN APPEARS

FAVORABLE FOR SMALL CLUSTERS OF STRONG...SLIGHTLY ELEVATED STORMS.

ASSOCIATED FORWARD-PROPAGATING SEGMENTS WILL BE CAPABLE OF SPORADIC

DMGG WIND GIVEN 30+ KT UNIDIRECTIONAL WSWLY MID LVL FLOW.  WHILE

MEAN FLOW APPEARS TO BE SLIGHTLY REDUCED RELATIVE TO EARLY

FRIDAY...COMBINATION OF EVEN MODERATE DEEP UNIDIRECTIONAL WIND FIELD

WITH PW AOA 1.75 INCHES AND RELATIVELY STEEP MID LVL LAPSE RATES MAY

SUPPORT PERSISTENCE OF EXISTING STORM CLUSTERS...AND PERHAPS

ADDITIONAL DEVELOPMENT OVER ERN IA...THROUGH LATER THIS MORNING.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION

VECTOR 26030.





...CORFIDI

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