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782 

WWUS20 KWNS 232044

SEL3

SPC WW 232044

SDZ000-240300-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 523

NWS STORM PREDICTION CENTER NORMAN OK

345 PM CDT FRI JUL 23 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       PARTS OF CENTRAL AND SOUTHERN SOUTH DAKOTA



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 345 PM UNTIL

1000 PM CDT.



TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 50 MILES WEST SOUTHWEST OF

PIERRE SOUTH DAKOTA TO 35 MILES EAST OF MITCHELL SOUTH DAKOTA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU3).



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 521...WW 522...



DISCUSSION...WITH A VERY UNSTABLE AIR MASS NOW IN PLACE ACROSS SRN

SD AHEAD OF APPROACHING COLD FRONT...THUNDERSTORMS EXPECTED TO

DEVELOP RAPIDLY IN WRN PORTION OF WATCH.  WITH VEERING SHEAR

PROFILES VICINITY E/W WARM FRONT THRU THE WATCH AND APPROACHING

UPPER TROUGH FROM MT...SUPERCELLS ARE LIKELY INCLUDING VERY LARGE

HAIL AND A TORNADO THREAT.  STORMS WILL THEN MOVE SLOWLY E/SE ACROSS

WATCH ALONG FAVORABLE INSTABILITY/MOISTURE AXIS.



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

SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

550. MEAN STORM MOTION VECTOR 28020.





...HALES

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