Lower Columbia Basin of Washington Severe Watches & Warnings NOAA Weather Radio

Watches & Warnings

Air Stagnation Advisory, Dense Fog Advisory
Issued: 8:07 AM PST Nov. 18, 2018 – National Weather Service

... Air stagnation advisory remains in effect until 1 PM PST
Wednesday...
... Dense fog advisory remains in effect until noon PST today...

* air quality... a ridge of high pressure will build across the
region and produce a low level inversion with light winds. Air
quality will slowly degrade over the period.

* Visibilities... one quarter of a mile or less at times.

* Timing... today through Wednesday.

* Impacts... limited visibilities will make travel very difficult.

Precautionary/preparedness actions...

An air stagnation advisory indicates that due to limited movement
of an air mass across the advisory area... pollution has the
potential to increase to dangerous levels. State air quality
agencies highly recommend that no outdoor burning occur and that
residential wood burning devices be limited as much as possible.
According to state air quality agencies... prolonged periods of
stagnant air can hold pollutants close to the ground. Check with
your local burn agency for any current restrictions in your area.

An air stagnation advisory indicates that due to limited movement
of an air mass across the advisory area... pollution has the
potential to increase to unhealthy levels. Persons with
respiratory illness should follow their physicians advice for
dealing with high levels of air pollution.

A dense fog advisory means visibilities will frequently be
reduced to less than one quarter mile. If driving... slow down...
use your headlights... and leave plenty of distance ahead of you.