Dense Fog Advisory issued December 6 at 11:54PM PST until December 7 at 9:00AM PST by NWS Portland OR

* WHAT…For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog. For the Air Stagnation Advisory, light winds
and limited air movement will lead to a period of stagnant air
conditions. This scenario could result in the build up of air
pollutants over time.

* WHERE…South Willamette Valley.

* WHEN…For the Dense Fog Advisory, until 9 AM PST Saturday. For
the Air Stagnation Advisory, until 4 AM PST Saturday.

* IMPACTS…Deteriorating air quality may cause issues for people
with respiratory problems. Low visibility could make driving
conditions hazardous.