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WWUS20 KWNS 301725

SEL2

SPC WW 301725

IAZ000-MIZ000-MNZ000-WIZ000-LSZ000-010000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 112

NWS STORM PREDICTION CENTER NORMAN OK

1225 PM CDT FRI APR 30 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEASTERN IOWA

       FAR WESTERN UPPER MICHIGAN

       SOUTHEASTERN MINNESOTA

       WESTERN WISCONSIN

       LAKE SUPERIOR



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 1225 PM UNTIL

700 PM CDT.



HAIL TO 1 INCH 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 EAST AND WEST OF A LINE FROM 90 MILES SOUTH

SOUTHWEST OF LA CROSSE WISCONSIN TO 25 MILES NORTH NORTHEAST OF

IRONWOOD 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.



OTHER WATCH INFORMATION...CONTINUE...WW 111...



DISCUSSION...STRONG UPPER FORCING WILL OVERSPREAD THE REGION THIS

AFTERNOON WITH INCREASING CHANCES FOR THUNDERSTORMS. ALTHOUGH

INSTABILITY WILL BE MARGINAL...THE FORCING COMBINED WITH STRONG

ENVIRONMENTAL WINDS FIELDS/SHEAR WILL SUPPORT FAST MOVING STORMS

WITH THE POTENTIAL FOR SEVERE HAIL. THE ENVIRONMENT IS ALSO

FAVORABLE FOR  MID LEVEL ROTATION..BOW SHAPED ECHOES...WITH A THREAT

FOR WIND DAMAGE.



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

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

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

VECTOR 21050.





...IMY

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