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000 

WWUS20 KWNS 022036

SEL2

SPC WW 022036

MTZ000-NEZ000-SDZ000-WYZ000-030400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 422

NWS STORM PREDICTION CENTER NORMAN OK

240 PM MDT MON JUN 2 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHEAST MONTANA

       NORTHWESTERN NEBRASKA PANHANDLE

       WESTERN SOUTH DAKOTA

       NORTH CENTRAL AND EASTERN WYOMING



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 240 PM UNTIL

1000 PM 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 125

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

NORTHWEST OF BUFFALO SOUTH DAKOTA TO 40 MILES SOUTH SOUTHEAST OF

DOUGLAS WYOMING.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



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 420...WW 421...



DISCUSSION...THUNDERSTORMS...INCLUDING ISOLATED SUPERCELLS...WILL

INCREASE IN COVERAGE/INTENSITY ACROSS WW THIS EVENING AHEAD OF LARGE

SHORTWAVE TROUGH MOVING ACROSS THE NRN ROCKIES.  AIR MASS OVER THE

HIGH PLAINS REMAINS RATHER MOIST AND MARGINAL TO MODERATELY

UNSTABLE...WITH EFFECTIVE SHEAR IN EXCESS OF 50 KT...SUGGESTING

STORMS WILL LIKELY ROTATE.  LARGE HAIL WILL BE PRIMARY SEVERE

THREAT...ALTHOUGH ISOLATED DAMAGING WINDS AND PERHAPS A BRIEF

TORNADO CAN ALSO BE EXPECTED.



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 450. MEAN STORM

MOTION VECTOR 25025.





...EVANS

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