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WWUS20 KWNS 281906

SEL9

SPC WW 281906

MNZ000-WIZ000-LSZ000-290100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 309

NWS STORM PREDICTION CENTER NORMAN OK

210 PM CDT MON MAY 28 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL AND EASTERN MINNESOTA

       NORTHWEST WISCONSIN

       LAKE SUPERIOR



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 210 PM UNTIL 800

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 95 MILES NORTHEAST OF

SAINT CLOUD MINNESOTA TO 25 MILES SOUTH SOUTHEAST OF MINNEAPOLIS

MINNESOTA.  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.



OTHER WATCH INFORMATION...CONTINUE...WW 308...



DISCUSSION...NEW TSTM DEVELOPMENT APPEARS LIKELY ALONG A FRONTAL

SURGE MOVING INTO CNTRL AND ERN MN THIS AFTERNOON. THIS DEVELOPMENT

WILL BE IN ADDITION TO THE ISOLATED ONGOING STORMS WEST OF DLH ATTM.

STRONG SURFACE HEATING HAS CONTRIBUTED TO MLCAPE AROUND 1000 J/KG

AHEAD OF THE FRONT/WIND SHIFT. EFFECTIVE SHEAR ACROSS THIS AREA IS

STRONG BENEATH A BAND OF 40-50KT MID LEVEL FLOW ALOFT. ASCENT ACROSS

THE BOUNDARY SHOULD BE AIDED BY STRONG DCVA ON THE POLEWARD SIDE OF

THE STRONGER JET MAX CROSSING WI ATTM. GIVEN THESE

CONDITIONS...EXPECT AN INCREASE IN STORMS AND STORM ORGANIZATION.

UPDRAFT PERSISTENCE AND FORCING ALONG THE ADVANCING WIND SHIFT WILL

LIKELY RESULT IN LINE SEGMENTS AND PERHAPS SUPERCELLS WITH A THREAT

FOR LARGE HAIL AND STRONG WINDS. AN ISOLATED TORNADO CANNOT BE

COMPLETELY RULED OUT...ESPECIALLY IF STORMS CAN INITIATE NEAR THE

WEAK SURFACE CIRCULATION WEST OF THE TWIN CITIES.



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 26030.





...CARBIN

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