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821 

WWUS20 KWNS 261956

SEL6

SPC WW 261956

MTZ000-NDZ000-SDZ000-WYZ000-270300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 416

NWS STORM PREDICTION CENTER NORMAN OK

200 PM MDT SAT JUN 26 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHEAST MONTANA

       SOUTHWEST NORTH DAKOTA

       WESTERN AND CENTRAL SOUTH DAKOTA

       NORTHEAST WYOMING



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 200 PM UNTIL

900 PM MDT.



HAIL TO 2.5 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 75

STATUTE MILES EITHER SIDE OF A LINE FROM 60 MILES WEST OF BUFFALO

SOUTH DAKOTA TO 50 MILES EAST SOUTHEAST OF PIERRE SOUTH DAKOTA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU6).



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 415...



DISCUSSION...AS UPPER TROUGH APPROACHES REGION...THUNDERSTORMS WILL

INCREASE IN COVERAGE. STRONG INSTABILITY AND 40 KT SHEAR WILL BE

FAVORABLE FOR A FEW SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS.



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

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 27030.





...IMY

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