

052 

WWUS20 KWNS 122033

SEL9

SPC WW 122033

IDZ000-ORZ000-WAZ000-130300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 459

NWS STORM PREDICTION CENTER NORMAN OK

135 PM PDT TUE AUG 12 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  A SMALL PART OF THE IDAHO PANHANDLE

  NORTHERN OREGON

  SOUTH CENTRAL AND SOUTHEAST WASHINGTON



* EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 135 PM UNTIL

  800 PM PDT.



* PRIMARY THREATS INCLUDE...

  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  ISOLATED LARGE HAIL EVENTS TO 1 INCH IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 80

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES NORTHWEST

OF THE DALLES OREGON TO 10 MILES EAST OF LEWISTON IDAHO.  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...CONVECTION IS EXPECTED TO INCREASE IN A

LOOSELY-ORGANIZED E-W BAND OVER NRN ORE AND SPREAD INTO WA THIS

AFTERNOON...IN ADVANCE OF A NWD-MOVING MIDLEVEL TROUGH.  DEEP

INVERTED-V PROFILES IN ADVANCE OF THE STORMS WILL FAVOR STRONG

DOWNDRAFTS AND THE POTENTIAL FOR A FEW DAMAGING GUSTS.  ALSO...THE

STRONGER STORMS COULD PRODUCE HAIL AROUND ONE INCH IN

DIAMETER...PRIMARILY NEAR THE CASCADES.



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

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM MOTION

VECTOR 18025.





...THOMPSON

