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039 

WWUS20 KWNS 210045

SEL0

SPC WW 210045

NDZ000-SDZ000-210700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 360

NWS STORM PREDICTION CENTER NORMAN OK

645 PM MDT SUN JUN 20 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWESTERN NORTH DAKOTA

       WESTERN AND CENTRAL SOUTH DAKOTA



EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 645 PM UNTIL

100 AM MDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80

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



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 100

STATUTE MILES EITHER SIDE OF A LINE FROM 55 MILES SOUTH SOUTHWEST

OF BUFFALO SOUTH DAKOTA TO 45 MILES NORTHEAST 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 357...WW 358...WW 359...



DISCUSSION...ONE CLUSTER OF SEVERE STORMS WAS MOVING EWD THROUGH WRN

SD...WHILE ANOTHER LARGER CLUSTER OF STORMS IS FORECAST TO EWD INTO

WRN SD/FAR SWRN ND DURING THE NEXT HOUR OR SO. WHILE THE MORE

DISCRETE STORMS ARE LIKELY TO PRODUCE LARGE HAIL...THESE STORMS ARE

EXPECTED TO EVENTUALLY EVOLVE INTO ONE OR MORE LINEAR MCS/S WITH

WIND DAMAGE BECOMING THE PRIMARY THREAT.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

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

MOTION VECTOR 27030.





...IMY

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