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471 

WWUS20 KWNS 282225

SEL9

SPC WW 282225

MTZ000-290600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 499

NWS STORM PREDICTION CENTER NORMAN OK

420 PM MDT WED AUG 28 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHERN AND EASTERN MONTANA



* EFFECTIVE THIS WEDNESDAY AFTERNOON FROM 420 PM UNTIL MIDNIGHT

  MDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2

    INCHES IN DIAMETER POSSIBLE

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 95

STATUTE MILES EAST AND WEST OF A LINE FROM 60 MILES NORTH

NORTHEAST OF GLASGOW MONTANA TO 30 MILES WEST OF BROADUS MONTANA.

 FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU9).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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.



&&



DISCUSSION...TSTMS EXPECTED TO INCREASE IN STRENGTH AND COVERAGE

THIS EVE ALONG AND E OF WEAK NW-SE WARM FRONT OVER ERN MT...AND

AHEAD OF SHORTWAVE IMPULSE TRACKING ENE FROM THE WRN PART OF THE

STATE. BACKED /SELY/ LOW-LVL FLOW...WEAK CONVERGENCE...AND PRESENCE

OF AMPLE MOISTURE /PW AOA 1.25 INCHES/ NE OF FRONT SUGGEST POTENTIAL

FOR A FEW ENE-MOVING SUPERCELLS WITH LARGE HAIL...LOCALLY DMGG

WIND...AND POSSIBLY A TORNADO. OTHER STORMS...MORE LIKELY ORGANIZED

INTO SHORT BANDS OR LEWPS AND POSING A THREAT FOR SVR

WIND/MARGINALLY SVR HAIL...MAY EVOLVE ALONG N-S COLD FRONT NOW

APPROACHING THE WRN PART OF THE WW. THIS ACTIVITY SHOULD ALSO MOVE

GENERALLY E OR ENEWD THROUGH LATE EVE.



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 500. MEAN STORM

MOTION VECTOR 25030.





...CORFIDI

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