

000 

WWUS20 KWNS 081829

SEL2

SPC WW 081829

MIZ000-MNZ000-WIZ000-LMZ000-LSZ000-090200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 492

NWS STORM PREDICTION CENTER NORMAN OK

130 PM CDT SUN JUL 8 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       THE CENTRAL AND WESTERN UPPER PENINSULA OF MICHIGAN

       EAST CENTRAL AND SOUTHEAST MINNESOTA

       NORTHERN WISCONSIN

       LAKE MICHIGAN

       LAKE SUPERIOR



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 130 PM UNTIL 900

PM CDT.



HAIL TO 2.5 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 65

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES NORTHWEST

OF MANKATO MINNESOTA TO 75 MILES NORTHEAST OF ESCANABA MICHIGAN.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU2).



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...ISOLATED STORMS ARE DEVELOPING NEAR STC IN MN.

ADDITIONAL STORMS WILL LIKELY DEVELOP ENEWD DURING THE NEXT FEW

HOURS ALONG A COLD FRONT ACROSS NRN WI INTO THE UPPER PENINSULA OF

MI AS THE CAP WEAKENS AND A MID LEVEL TROUGH APPROACHES FROM SD.

STRONG INSTABILITY IS PRESENT ALONG AND IMMEDIATE S OF THE

BOUNDARY...AND EFFECTIVE BULK SHEAR IN EXCESS OF 40 KT WILL FAVOR

SUPERCELLS.  LARGE HAIL...SOME SIGNIFICANT...AND DAMAGING WINDS WILL

BE THE MAIN THREATS.  THOUGH SUPERCELLS ARE EXPECTED...THE TORNADO

THREAT SHOULD GENERALLY BE LIMITED BY WEAK LOW-LEVEL SHEAR.



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

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 30025.





...THOMPSON

