

000 

WWUS20 KWNS 281721

SEL9

SPC WW 281721

MNZ000-WIZ000-290100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 659

NWS STORM PREDICTION CENTER NORMAN OK

1215 PM CDT TUE AUG 28 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTH CENTRAL AND SOUTHEASTERN MINNESOTA

       WESTERN AND NORTHERN WISCONSIN



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 1215 PM UNTIL

800 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 60

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

NORTHWEST OF FAIRMONT MINNESOTA TO 65 MILES EAST SOUTHEAST OF

RHINELANDER WISCONSIN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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...STRONG INSTABILITY IN PLACE AHEAD OF WEAK IMPULSE

EJECTING NEWD OUT OF THE UPPER MS VALLEY WILL SUPPORT TSTM

DEVELOPMENT INTO SERN MN AND WI.  EFFECTIVE BULK SHEAR OF 40-50 KT

AND ASCENT ATTENDANT WITH THIS IMPULSE WILL ENHANCE SEVERE TSTM

DEVELOPMENT...INCLUDING SUPERCELLS AND BOW ECHOES.  PRIMARY SEVERE

WEATHER THREATS EXPECTED TO BE DAMAGING WINDS AND LARGE HAIL.



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 500. MEAN STORM

MOTION VECTOR 26035.





...PETERS/EVANS

