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000 

WWUS20 KWNS 171029

SEL6

SPC WW 171029

MTZ000-NDZ000-171800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 406

NWS STORM PREDICTION CENTER NORMAN OK

430 AM MDT SUN JUN 17 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHERN AND EASTERN MONTANA

       WESTERN AND CENTRAL NORTH DAKOTA



EFFECTIVE THIS SUNDAY MORNING FROM 430 AM UNTIL NOON MDT.



HAIL TO 1.5 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 65

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 105 MILES WEST

SOUTHWEST OF MILES CITY MONTANA TO 40 MILES EAST SOUTHEAST OF

MINOT NORTH 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...THIS SEVERE THUNDERSTORM WATCH REPLACES

SEVERE THUNDERSTORM WATCH NUMBER 403...SEVERE THUNDERSTORM WATCH

NUMBER 404. WATCH NUMBER 403 404 WILL NOT BE IN EFFECT AFTER 430

AM MDT. CONTINUE...WW 405...



DISCUSSION...FAST-MOVING ELEVATED SUPERCELLS ON NW EDGE OF 700 MB

THERMAL RIDGE EXPECTED TO CONTINUE GENERALLY ENE...WITH ATTENDANT

THREAT FOR HAIL AND POSSIBLY HIGH WIND AS RIDGE AMPLIFIES SLIGHTLY

NEWD INTO CNTRL/ERN ND.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 26045.





...CORFIDI

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