

290 

WWUS20 KWNS 130030

SEL0

SPC WW 130030

SDZ000-130700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 470

NWS STORM PREDICTION CENTER NORMAN OK

635 PM MDT SUN JUN 12 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL SOUTH DAKOTA



EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 635 PM UNTIL

100 AM MDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 70

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTHWEST OF

MOBRIDGE SOUTH DAKOTA TO 85 MILES SOUTH SOUTHEAST OF PHILIP SOUTH

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

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



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 468...WW 469...



DISCUSSION...SCATTERED INTENSE THUNDERSTORMS OVER WESTERN SD WILL

LIKELY MAINTAIN SEVERITY SEVERAL MORE HOURS AND TRACK EASTWARD

ACROSS WATCH.  A STRENGTHENING CAPPING INVERSION WILL LIKELY

SUPPRESS TORNADO POTENTIAL...BUT STRONG LOW LEVEL WINDS AND

SUFFICIENT INSTABILITY WILL KEEP A RISK OF LARGE HAIL AND DAMAGING

WINDS.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 26030.





...HART

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