

194 

WWUS20 KWNS 252148

SEL4

SPC WW 252148

SDZ000-260500-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 514

NWS STORM PREDICTION CENTER NORMAN OK

450 PM CDT THU JUN 25 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       PARTS OF WESTERN SOUTH DAKOTA



EFFECTIVE THIS THURSDAY AFTERNOON FROM 450 PM UNTIL MIDNIGHT CDT.



TORNADOES...HAIL TO 3 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 55 STATUTE

MILES EAST AND WEST OF A LINE FROM 85 MILES NORTH NORTHEAST OF

RAPID CITY SOUTH DAKOTA TO 75 MILES SOUTH SOUTHWEST OF PHILIP

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

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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.



OTHER WATCH INFORMATION...CONTINUE...WW 508...WW 509...WW

510...WW 511...WW 512...WW 513...



DISCUSSION...A VERY UNSTABLE AIR MASS RESIDES OVER AND E OF BLACK

HILLS ALONG WITH A COUPLE N/S BOUNDARIES.  THUNDERSTORMS SHOULD

RAPIDLY DEVELOP VICINITY OF BLACK HILLS AND THEN MOVE EWD THIS

EVENING.  WITH THE BOUNDARIES AND EXPECTED INCREASE IN LOW LEVEL JET

TO 30KT THIS EVENING...SUPERCELLS ARE LIKELY. IN ADDITION TO LARGE

HAIL...TORNADOES WILL BE POSSIBLE ASSOCIATED WITH ANY SUPERCELL.



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

SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE

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

550. MEAN STORM MOTION VECTOR 27015.





...HALES

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