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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 511

NWS STORM PREDICTION CENTER NORMAN OK

1235 PM PDT THU SEP 5 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHERN AND WESTERN IDAHO

  NORTHEAST NEVADA

  THE EASTERN TWO-THIRDS OREGON

  SOUTHERN WASHINGTON



* EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 1235 PM

  UNTIL 800 PM PDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL DAMAGING WIND GUSTS WITH A FEW SIGNIFICANT GUSTS TO 75

    MPH POSSIBLE

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

    INCHES IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 125

STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES NORTHEAST OF

WALLA WALLA WASHINGTON TO 65 MILES SOUTH SOUTHWEST OF ROME

OREGON.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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 CONTINUE TO GRADUALLY DEVELOP THIS

AFTERNOON ACROSS PORTIONS OF OREGON AND VICINITY...AS AN UPPER LOW

AND ASSOCIATED/POTENT MID-LEVEL SPEED MAX SHIFTS NEWD INTO THE

REGION.  A MOIST LOW-LEVEL AIRMASS CONTINUES TO HEAT/DESTABILIZE

THIS AFTERNOON...WHICH WILL SUPPORT CONTINUED/INCREASINGLY

WIDESPREAD STORM DEVELOPMENT.  GIVEN THE INCREASING FLOW

ALOFT...STORMS WILL ORGANIZE QUICKLY...WITH INITIALLY ROTATING CELLS

POSSIBLY GROWING UPSCALE INTO SMALL-SCALE LINES WITH TIME.  AS

SUCH...LARGE HAIL AND LOCALLY DAMAGING WINDS ARE EXPECTED ACROSS

THIS REGION INTO THE EVENING.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65

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

MOTION VECTOR 20040.





...GOSS

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