Smoke + high pressure = Air stagnation advisory

Smoke + high pressure = Air stagnation advisory
Image courtesy: National Weather Service

NATIONAL WEATHER SERVICE FORECAST -- STAGNANT AIR CONDITIONS ACROSS THE YAKIMA AND KITTITAS VALLEYS THROUGH WEDNESDAY...

.A BUILDING RIDGE OF HIGH PRESSURE WILL RESULT IN STAGNANT AIR
CONDITIONS THROUGH AT LEAST MID WEEK IN THE YAKIMA AND KITTITAS VALLEYS.

INCLUDING THE CITIES OF...ELLENSBURG...THORP...NACHES...
SUNNYSIDE...TOPPENISH...YAKIMA
852 AM PDT MON SEP 17 2012

...AIR STAGNATION ADVISORY IN EFFECT UNTIL 5 PM PDT WEDNESDAY...

THE NATIONAL WEATHER SERVICE IN PENDLETON HAS ISSUED AN AIR
STAGNATION ADVISORY...WHICH IS IN EFFECT UNTIL 5 PM PDT
WEDNESDAY.

* TIMING: STAGNANT CONDITIONS WILL CONTINUE INTO AT LEAST
  WEDNESDAY. THESE CONDITIONS ARE EXPECTED TO BE MOST PREVALENT
  AT NIGHT.

* IMPACTS: SMOKE FROM REGIONAL FIRES MAY FILTER INTO THE AREA AND
  BE NEAR THE SURFACE ESPECIALLY AT NIGHT. THIS MAY REDUCE AIR
  QUALITY.

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.