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WWUS20 KWNS 081902

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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 398

NWS STORM PREDICTION CENTER NORMAN OK

105 PM MDT MON JUL 8 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  SOUTH CENTRAL MONTANA



* EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 105 PM UNTIL

  700 PM MDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL VERY LARGE HAIL EVENTS TO 2.5 INCHES IN DIAMETER

    POSSIBLE

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  A FEW TORNADOES POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 85

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 40 MILES SOUTH

SOUTHWEST OF HELENA MONTANA TO 50 MILES NORTHEAST OF BILLINGS

MONTANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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...THUNDERSTORMS ARE EXPECTED TO CONTINUE TO INTENSIFY

THIS AFTERNOON OVER THE MOUNTAINS OF SOUTHWEST MT AND SPREAD

EASTWARD ACROSS THE WATCH AREA.  STRONG VERTICAL SHEAR AND MODERATE

CAPE VALUES WILL PROMOTE SUPERCELL STORMS CAPABLE OF VERY LARGE HAIL

AND DAMAGING WINDS.  ACTIVITY MAY ORGANIZE INTO ONE OR MORE BOW

ECHOES BY EARLY EVENING.



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

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 27035.





...HART

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