

000 

WWUS20 KWNS 281746

SEL1

SPC WW 281746

WIZ000-LMZ000-290000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 631

NWS STORM PREDICTION CENTER NORMAN OK

1250 PM CDT SAT JUN 28 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       A LARGE PART OF WISCONSIN

       LAKE MICHIGAN



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 1250 PM UNTIL

700 PM CDT.



HAIL TO 2 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 90

STATUTE MILES EAST AND WEST OF A LINE FROM 15 MILES EAST

SOUTHEAST OF JANESVILLE WISCONSIN TO 25 MILES NORTHEAST OF WAUSAU

WISCONSIN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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 628...WW 629...WW 630...



DISCUSSION...POTENT COLD UPPER LOW MOVING EWD ACROSS WI ACCOMPANIED

BY STEEP LAPSE RATES AND MODEST INSTABILITY.  THUNDERSTORMS ARE

INCREASING RAPIDLY AND WILL BE EFFICIENT HAIL PRODUCERS.  SHEAR WITH

UPPER LOW SUPPORT POSSIBLE SUPERCELLS WHICH WILL ENHANCE HAIL AND

WIND THREAT WITH POSSIBLE BRIEF TORNADO POTENTIAL.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM

MOTION VECTOR 24025.





...HALES

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