

000 

WWUS20 KWNS 102246

SEL4

SPC WW 102246

MTZ000-NDZ000-110600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 584

NWS STORM PREDICTION CENTER NORMAN OK

445 PM MDT FRI AUG 10 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEAST MONTANA

       WESTERN NORTH DAKOTA



EFFECTIVE THIS FRIDAY AFTERNOON FROM 445 PM UNTIL MIDNIGHT 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 75

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 75 MILES WEST OF

GLASGOW MONTANA TO 35 MILES NORTH OF BISMARCK NORTH DAKOTA.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 580...WW 581...WW

582...WW 583...



DISCUSSION...SCATTERED THUNDERSTORMS ARE EXPECTED TO INTENSIFY THIS

EVENING ACROSS NORTHEAST MT AND WESTERN ND...IN REGION OF WEAKENING

CAP AND APPROACHING LARGE SCALE UPPER SUPPORT.  STEEP LOW LEVEL

LAPSE RATES AND FAVORABLE EFFECTIVE SHEAR VALUES SUPPORT A RISK OF

SUPERCELL STORMS EARLY...FOLLOWED BY UPSCALE GROWTH INTO AN MCS WITH

ENHANCED DAMAGING WIND 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 27035.





...HART

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