

000 

WWUS20 KWNS 250437

SEL9

SPC WW 250437

MTZ000-NDZ000-251200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 449

NWS STORM PREDICTION CENTER NORMAN OK

1135 PM CDT SUN JUN 24 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       MUCH OF EASTERN MONTANA

       MUCH OF NORTH DAKOTA



EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 1135 PM UNTIL

700 AM CDT.



HAIL TO 3 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 115 MILES SOUTHWEST

OF GLASGOW MONTANA TO 15 MILES NORTH NORTHEAST OF GRAND FORKS

NORTH DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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...THIS SEVERE THUNDERSTORM WATCH REPLACES

TORNADO WATCH NUMBER 447...SEVERE THUNDERSTORM WATCH NUMBER 448.

WATCH NUMBER 447 448 WILL NOT BE IN EFFECT AFTER 1135 PM CDT.



DISCUSSION...CLUSTERS OF SEVERE THUNDERSTORMS CONTINUE TO DEVELOP

EWD ACROSS ERN MT WITH ADDITIONAL SEVERE THUNDERSTORMS DEVELOPING N

OF FRONTAL ZONE NRN ND, WITH VERY TO EXTREMELY UNSTABLE AIR MASS

REMAINING ALONG WITH FAVORABLE VEERING SHEAR PROFILES...SEVERE

THUNDERSTORMS INCLUDING SUPERCELLS WILL CONTINUE DEVELOPING EWD

ACROSS THE WATCH AREA.  VERY LARGE HAIL WILL BE PRIMARY THREAT WITH

SUPERCELLS...WITH DAMAGING WINDS...PARTICULARLY ASSOCIATED WITH

DEVELOPMENT OF LINE SEGMENTS/BOW ECHOES.



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

TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600. MEAN STORM

MOTION VECTOR 26030.





...HALES

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