The Tri-Cities can look forward to patchy fog and stagnant air the rest of the week.
The National Weather Service has issued an air stagnation advisory through 10 a.m. Saturday. A strong upper high pressure system will result in light winds and poor mixing of air near the ground in the Tri-City area, according to the weather service.
The stagnant air will increase pollution and cause air quality to deteriorate.
The fog could pose a driving hazard. Patches of freezing fog are expected before 10 a.m. today, Thursday and likely Friday.