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186 

WWUS20 KWNS 212218

SEL8

SPC WW 212218

MNZ000-WIZ000-220500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 338

NWS STORM PREDICTION CENTER NORMAN OK

520 PM CDT FRI JUN 21 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  SOUTHEAST MINNESOTA

  WESTERN WISCONSIN



* EFFECTIVE THIS FRIDAY AFTERNOON FROM 520 PM UNTIL MIDNIGHT CDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL DAMAGING WIND GUSTS WITH A FEW SIGNIFICANT GUSTS TO 80

    MPH POSSIBLE

  SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2

    INCHES IN DIAMETER POSSIBLE

  A FEW TORNADOES POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 85

STATUTE MILES EAST AND WEST OF A LINE FROM 70 MILES NORTH OF EAU

CLAIRE WISCONSIN TO 25 MILES WEST OF ROCHESTER MINNESOTA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU8).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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 336...WW 337...



DISCUSSION...AN MCS WITH DAMAGING WINDS HAS CROSSED THE SD-MN BORDER

AND WAS MOVING ENEWD AT OVER 40KT. THIS SYSTEM IS LOCATED ON A SHARP

INSTABILITY GRADIENT THAT ALSO DEFINES THE NORTHERN EDGE OF STRONG

CAPPING INVERSION. STRONG INSTABILITY AND PRONOUNCED DIRECTIONAL AND

SPEED SHEAR THROUGH THE CLOUD-BEARING LAYER WILL ACT TO MAINTAIN THE

SEVERE MCS WITH DAMAGING WIND AND LARGE HAIL THREATS SPREADING EAST

INTO PORTIONS OF SE MN AND WRN WI DURING THE EVENING HOURS.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

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

MOTION VECTOR 25040.





...CARBIN

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