Dense Fog Advisory issued December 5 at 4:03PM PST until December 6 at 11:00AM PST by NWS Portland OR

* WHAT…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. For the Dense Fog Advisory, visibility frequently below one
quarter mile in dense fog and areas of freezing fog.

* WHERE…South Willamette Valley.

* WHEN…For the Air Stagnation Advisory, until 4 AM PST Saturday.
For the Dense Fog Advisory, until 11 AM PST Friday.

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

* ADDITIONAL DETAILS…Fog will reform and increase across the south
Willamette Valley this evening. Overall, temperatures will hold at
or just above freezing overnight. But, a few spots will drop back
below freezing. As such, motorists should be prepared for
potentially icy or slick spots, especially on less-traveled rural
roadways and bridges.