AIR STAGNATION ADVISORY
Issue Date: 526 AM PST FRI DEC 25 2009
Expiration: 400 PM PST SAT DEC 26 2009

...AIR STAGNATION ADVISORY REMAINS IN EFFECT UNTIL 4 PM PST
SATURDAY...
AN AIR STAGNATION ADVISORY REMAINS IN EFFECT UNTIL 4 PM PST
SATURDAY.
* AIR QUALITY WILL DETERIORATE IN VALLEYS AND BASINS DUE TO HIGH
  PRESSURE LIMITING AIR MOVEMENT. THIS WILL CAUSE THE
  ACCUMULATION OF PARTICULATE MATTER IN VALLEYS AND BASINS BELOW
  3500 FEET.
* POOR AIR QUALITY WILL AFFECT PERSONS WITH RESPIRATORY PROBLEMS
  AND PERSONS ENGAGED IN STRENUOUS OUTDOOR ACTIVITIES.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
AN AIR STAGNATION ADVISORY INDICATES THAT DUE TO LIMITED MOVEMENT
OF AN AIR MASS ACROSS THE ADVISORY AREA...POLLUTION WILL
INCREASE. CHECK WITH YOUR LOCAL AIR QUALITY AGENCY FOR POSSIBLE
RESTRICTIONS IN YOUR AREA. FOR ADDITIONAL WEATHER INFORMATION...
CHECK OUR WEBSITE AT WWW.WEATHER.GOV/PENDLETON.
&&
$$

HAZARDOUS WEATHER OUTLOOK
Issue Date: 520 AM PST FRI DEC 25 2009
Expiration: 515 AM PST SAT DEC 26 2009

Expires:200912261315;;
FLUS46 KPDT 251319
HWOPDT
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
520 AM PST FRI DEC 25 2009
ORZ041>044-049-050-501>506-WAZ024-026>030-501-502-261315-
EASTERN COLUMBIA RIVER GORGE OF OREGON-NORTH CENTRAL OREGON-
CENTRAL OREGON-LOWER COLUMBIA BASIN OF OREGON-GRANDE RONDE VALLEY-
WALLOWA COUNTY-FOOTHILLS OF THE BLUE MOUNTAINS OF OREGON-
NORTHERN BLUE MOUNTAINS OF OREGON-
SOUTHERN BLUE MOUNTAINS OF OREGON-
NORTHERN WHEELER AND SOUTHERN GILLIAM COUNTIES-JOHN DAY BASIN-
OCHOCO-JOHN DAY HIGHLANDS-
EASTERN COLUMBIA RIVER GORGE OF WASHINGTON-KITTITAS VALLEY-
YAKIMA VALLEY-LOWER COLUMBIA BASIN OF WASHINGTON-
FOOTHILLS OF THE BLUE MOUNTAINS OF WASHINGTON-
NORTHWEST BLUE MOUNTAINS-
EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON-
EAST SLOPES OF THE SOUTHERN CASCADES OF WASHINGTON-
520 AM PST FRI DEC 25 2009
THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL AND NORTHEAST OREGON
AS WELL AS SOUTH CENTRAL AND SOUTHEAST WASHINGTON.
.DAY ONE...TODAY AND TONIGHT
DENSE FOG
     CENTRAL OREGON
A LAYER OF LOW STRATUS CLOUDS HAS SPREAD TO CENTRAL OREGON AND HAS
COME INTO CONTACT WITH THE RISING TERRAIN OF THE CENTRAL OREGON
PLATEAU FROM NEAR REDMOND SOUTHWARD. THIS IS CAUSING AREAS OF DENSE
FREEZING FOG...ESPECIALLY ON HIGHWAY 97 FROM REDMOND TO BEND...OR
FROM ELEVATIONS FROM ABOUT 2500 TO 4000  FEET. AS A RESULT A DENSE
FOG ADVISORY IS IN EFFECT FOR CENTRAL OREGON UNTIL NOON TODAY.
PLEASE REFER TO NWS PRODUCT ID PDXNPWPDT FOR MORE DETAILS.
AIR STAGNATION ADVISORY TODAY AND TONIGHT
     EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON, EAST SLOPES
     OF THE SOUTHERN CASCADES OF WASHINGTON, EASTERN COLUMBIA RIVER
     GORGE OF WASHINGTON, KITTITAS VALLEY, YAKIMA VALLEY, LOWER
     COLUMBIA BASIN OF WASHINGTON, FOOTHILLS OF THE BLUE MOUNTAINS
     OF WASHINGTON, EASTERN COLUMBIA RIVER GORGE OF OREGON, NORTH
     CENTRAL OREGON, CENTRAL OREGON, LOWER COLUMBIA BASIN OF
     OREGON, GRANDE RONDE VALLEY, FOOTHILLS OF THE BLUE MOUNTAINS
     OF OREGON, NORTHERN WHEELER AND SOUTHERN GILLIAM COUNTIES,
     JOHN DAY BASIN
IN ADDITION THE COMBINATION OF A STRONG HIGH PRESSURE RIDGE ALOFT
WITH LIGHT SURFACE WINDS AND STRONG SURFACE BASED TEMPERATURE
INVERSIONS HAS LEAD TO STAGNANT AIR CONDITIONS WITH INCREASING
TRAPPED POLLUTANTS IN THE AREAS LISTED ABOVE. AS SUCH AN AIR
STAGNATION ADVISORY IS IN EFFECT FOR THESE AREAS. PLEASE REFER TO
PDXNPWPDT FOR MORE DETAILS.
.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY
AIR STAGNATION ADVISORY SATURDAY
     EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON, EAST SLOPES
     OF THE SOUTHERN CASCADES OF WASHINGTON, EASTERN COLUMBIA RIVER
     GORGE OF WASHINGTON, KITTITAS VALLEY, YAKIMA VALLEY, LOWER
     COLUMBIA BASIN OF WASHINGTON, FOOTHILLS OF THE BLUE MOUNTAINS
     OF WASHINGTON, EASTERN COLUMBIA RIVER GORGE OF OREGON, NORTH
     CENTRAL OREGON, CENTRAL OREGON, LOWER COLUMBIA BASIN OF
     OREGON, GRANDE RONDE VALLEY, FOOTHILLS OF THE BLUE MOUNTAINS
     OF OREGON, NORTHERN WHEELER AND SOUTHERN GILLIAM COUNTIES,
     JOHN DAY BASIN
THE AIR STAGNATION ADVISORY IN IN EFFECT THROUGH 4 PM SATURDAY
AFTERNOON DUE TO LIGHT WINDS...STRONG SURFACE BASED TEMPERATURE
INVERSIONS AND A HIGH PRESSURE RIDGE ALOFT CREATING STAGNANT
CONDITIONS IN THE AREAS LISTED ABOVE. PLEASE REFER TO PDXNPWPDT FOR
MORE DETAILS. ELSEWHERE OTHER THAN THE AREAS LISTED ABOVE MOSTLY
CLEAR SKIES WITH SLOWLY MODERATING TEMPERATURES AND DRY CONDITIONS
ARE EXPECTED THROUGH THE WEEKEND. WEATHER SYSTEMS ARE THEN EXPECTED
TO RETURN TO THE REGION NEXT WEEK WITH A THREAT OF RAIN OR SNOW
ACROSS THE FORECAST AREA.
.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
GRAPHICAL FORECASTS OF WEATHER HAZARDS OUT TO SEVEN DAYS
ARE DISPLAYED ON THE WORLD WIDE WEB AT:
WWW.WRH.NOAA.GOV/PDT/CURRENTHAZARDS/HWO.HTML
ALL LETTERS IN THE ABOVE URL ARE LOWER CASE...EXCEPT THE H IN
CURRENTHAZARDS.
$$