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568 

WWUS20 KWNS 260617

SEL1

SPC WW 260617

SDZ000-261400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 221

NWS STORM PREDICTION CENTER NORMAN OK

115 AM CDT SUN MAY 26 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHERN AND CENTRAL SOUTH DAKOTA



* EFFECTIVE THIS SUNDAY MORNING FROM 115 AM UNTIL 900 AM CDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL VERY LARGE HAIL EVENTS TO 2.5 INCHES IN DIAMETER

    POSSIBLE

  A FEW DAMAGING WIND GUSTS TO 70 MPH POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 55

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 75 MILES NORTHWEST

OF PHILIP SOUTH DAKOTA TO 55 MILES NORTH NORTHEAST OF CHAMBERLAIN

SOUTH DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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.



&&



DISCUSSION...SVR TSTMS CONTINUE TO FORM IN WAA ZONE ATOP

SHALLOW...SFC-BASED STABLE LAYER N OF WNW-ESE ORIENTED STNRY FRONT.

SUFFICIENT CLOUD-LAYER SHEAR APPEARS PRESENT FOR A FEW ELEVATED

SUSTAINED STORMS/SUPERCELLS WITH LARGE HAIL AND LOCALLY DMGG WIND.



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 30035.





...CORFIDI

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