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000 

WWUS20 KWNS 030750

SEL0

SPC WW 030750

SDZ000-031500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 430

NWS STORM PREDICTION CENTER NORMAN OK

150 AM MDT TUE JUN 3 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN AND SOUTHERN SOUTH DAKOTA



EFFECTIVE THIS TUESDAY MORNING FROM 150 AM UNTIL 900 AM MDT.



HAIL TO 1.5 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 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES WEST

NORTHWEST OF RAPID CITY SOUTH DAKOTA TO 55 MILES SOUTHEAST OF

PIERRE 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 427...WW 428...WW 429...



DISCUSSION...SMALL MCS WITH EMBEDDED SUSTAINED/POSSIBLE SUPERCELL

STRUCTURES JUST CROSSING INTO WRN SD EXPECTED TO CONTINUE MAINLY ESE

AS ASSOCIATED UPR TROUGH IN ERN MT CONTINUES EWD.  ALTHOUGH

INTERACTION OF MCS WITH BLACK HILLS CASTS UNCERTAINTY ON SYSTEMS

FUTURE EVOLUTION/ STRENGTH...REGIONAL VWP DATA AND FORCING FROM

SHORTWAVE IMPULSE SUGGEST POTENTIAL FOR ADDITIONAL SVR HAIL/WIND

DESPITE UNKNOWN INFLUENCE FROM MOUNTAINS AND UNFAVORABLE TIME OF

DAY.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM

MOTION VECTOR 29035.





...CORFIDI

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