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000 

WWUS20 KWNS 280701

SEL7

SPC WW 280701

MNZ000-WIZ000-281100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 657

NWS STORM PREDICTION CENTER NORMAN OK

200 AM CDT TUE AUG 28 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHERN MINNESOTA

       WESTERN WISCONSIN



EFFECTIVE THIS TUESDAY MORNING FROM 200 AM UNTIL 600 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 45 MILES NORTHWEST

OF MANKATO MINNESOTA TO 35 MILES NORTHEAST OF EAU CLAIRE

WISCONSIN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



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.



DISCUSSION...SMALL FORWARD-PROPAGATING MCS HAS FORMED IN THE PAST

HOUR IN SW MN.  SYSTEM SHOULD CONTINUE ENE INTO W CNTRL WI LATER

THIS MORNING... ALONG AND JUST N OF VERY SHALLOW OUTFLOW BOUNDARY

NOW OVER THE SRN SUBURBS OF METRO MSP.  MODERATE TO STRONG...DEEP

UNIDIRECTIONAL WSW FLOW AND DEGREE OF INSTABILITY LIKELY PRESENT

ABOVE OUTFLOW BOUNDARY SUGGEST POTENTIAL FOR DAMAGING WIND AND

MARGINALLY SVR HAIL AS SYSTEM CONTINUES ENEWD.



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 500. MEAN STORM

MOTION VECTOR 25040.





...CORFIDI

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