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295 

WWUS20 KWNS 222209

SEL2

SPC WW 222209

NDZ000-SDZ000-230600-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 202

NWS STORM PREDICTION CENTER NORMAN OK

510 PM CDT SAT MAY 22 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       SOUTHEAST NORTH DAKOTA

       EASTERN SOUTH DAKOTA



EFFECTIVE THIS SATURDAY AFTERNOON AND SUNDAY MORNING FROM 510 PM

UNTIL 100 AM CDT.



TORNADOES...HAIL TO 4 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE

MILES EAST AND WEST OF A LINE FROM 30 MILES NORTHEAST OF

JAMESTOWN NORTH DAKOTA TO 55 MILES EAST SOUTHEAST OF PIERRE SOUTH

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

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



DISCUSSION...SUPERCELL THUNDERSTORMS ARE EXPECTED TO RAPIDLY

INTENSIFY THIS AFTERNOON NEAR SURFACE LOW OVER CENTRAL SD...AND

TRACK NORTHEASTWARD ACROSS THE WATCH AREA.  EXTREME

INSTABILITY...COUPLED WITH FAVORABLE LOW LEVEL AND DEEP LAYER

VERTICAL SHEAR WILL PROMOTE A RISK OF VERY LARGE HAIL AND TORNADOES.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 4 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

550. MEAN STORM MOTION VECTOR 25035.





...HART

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