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000 

WWUS20 KWNS 101655

SEL4

SPC WW 101655

MIZ000-WIZ000-LMZ000-LSZ000-110100-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 504

NWS STORM PREDICTION CENTER NORMAN OK

1155 AM CDT TUE JUL 10 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       THE UPPER PENINSULA OF MICHIGAN

       NORTHEAST WISCONSIN

       LAKE MICHIGAN

       LAKE SUPERIOR



EFFECTIVE THIS TUESDAY MORNING AND EVENING FROM 1155 AM UNTIL 800

PM 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 70 STATUTE

MILES EAST AND WEST OF A LINE FROM 40 MILES NORTH NORTHEAST OF

MARQUETTE MICHIGAN TO 25 MILES SOUTHWEST OF GREEN BAY WISCONSIN.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU4).



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.



DISCUSSION...SCATTERED THUNDERSTORMS WILL LIKELY DEVELOP EARLY THIS

AFTERNOON ALONG A PRE-FRONTAL TROUGH MOVING EWD ACROSS WI/UPPER MI.

MODERATE INSTABILITY IN THE WARM SECTOR...IN COMBINATION WITH STRONG

DEEP LAYER VERTICAL SHEAR...SHOULD SUPPORT A FEW DISCRETE SUPERCELLS

WITH THE INITIAL DEVELOPMENT.  RELATIVELY RICH LOW-LEVEL MOISTURE

AND STRONGER LOW-LEVEL SHEAR OVER EXTREME NE WI AND UPPER MI MAY

SUPPORT A FEW TORNADOES WITH THE SUPERCELLS.  THE THREAT FOR

DAMAGING WINDS SHOULD ALSO INCREASE AS STORM COVERAGE INCREASES

THROUGH THE AFTERNOON...AND STORM INTERACTIONS LEAD TO MORE LINE

SEGMENT DEVELOPMENT.



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 25035.





...THOMPSON

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