HAZARDOUS WEATHER OUTLOOK
Issue Date: 523 AM PST THU DEC 24 2009
Expiration: 430 AM PST FRI DEC 25 2009

Expires:200912251230;;
FLUS46 KPDT 241323
HWOPDT
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
520 AM PST THU DEC 24 2009
ORZ041>044-049-050-501>506-WAZ024-026>030-501-502-251230-
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 THU DEC 24 2009
THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL AND NORTHEAST OREGON
AS WELL AS SOUTH CENTRAL AND SOUTHEAST WASHINGTON.
.DAY ONE...TODAY AND TONIGHT
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
THE COMBINATION OF A HIGH PRESSURE RIDGE ALOFT WITH LIGHT SURFACE
WINDS AND STRONG SURFACE BASED TEMPERATURE INVERSIONS WILL LEAD TO
INCREASING AREAS OF FOG AND/OR LOW CLOUDS BEGINNING TODAY AND
TONIGHT. THIS WILL RESULT IN 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...FRIDAY THROUGH WEDNESDAY
AIR STAGNATION ADVISORY FRIDAY AND 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.
$$

AIR STAGNATION ADVISORY
Issue Date: 225 PM PST WED DEC 23 2009
Expiration: 400 PM PST SAT DEC 26 2009

...AIR STAGNATION ADVISORY IN EFFECT FROM 4 AM THURSDAY TO 4 PM
PST SATURDAY...
THE NATIONAL WEATHER SERVICE IN PENDLETON HAS ISSUED AN AIR
STAGNATION ADVISORY...WHICH IS IN EFFECT FROM 4 AM THURSDAY TO
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 MAINLY BELOW 3500
FEET.
* IMPACTS: 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.
$$