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WWUS20 KWNS 060105

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SPC WW 060105

IDZ000-MTZ000-WAZ000-060800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 513

NWS STORM PREDICTION CENTER NORMAN OK

705 PM MDT THU SEP 5 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHERN IDAHO INCLUDING PANHANDLE

  WESTERN MONTANA

  EASTERN AND CENTRAL WASHINGTON



* EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 705 PM

  UNTIL 200 AM MDT.



* PRIMARY THREATS INCLUDE...

  A FEW DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  A FEW LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 90

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

NORTHWEST OF WENATCHEE WASHINGTON TO 45 MILES EAST OF HELENA

MONTANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).



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.



&&



OTHER WATCH INFORMATION...CONTINUE...WW 511...WW 512...



DISCUSSION...SYNOPTICALLY AIDED BAND OF STG-SVR CONVECTION IS

EXPECTED TO SHIFT/SPREAD NWD ACROSS WW AREA THROUGH REMAINDER

EVENING INTO OVERNIGHT HOURS.  THOUGH NEAR-SFC AIR MASS WILL

GRADUALLY STABILIZE FROM DIABATIC COOLING...LARGE-SCALE ASCENT AND

INCREASING TSTM ORGANIZATION MAY OFFSET THAT ENOUGH TO MAINTAIN SVR

HAIL/GUST THREAT NWD FROM PRIOR WWS.  REF SPC MESOSCALE DISCUSSIONS

1842-1843 FOR ADDITIONAL DETAILS.



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 450. MEAN STORM

MOTION VECTOR 21035.





...EDWARDS

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