Low level inversions are expected to return to the Tri-Cities.
The National Weather Service has issued a stagnant air advisory for much of eastern Washington and Oregon, including the Tri-Cities, starting at 10 p.m. Saturday and continuing through 4 p.m. Tuesday. The advisory means that pollution will increase because of limited movement of an air mass across the area.
The inversion will trap pollutants near the surface, which can impact people with respiratory conditions, the weather service said.
Patchy freezing fog could impact driving until Tuesday, though people will also see some sunny and clear conditions, the weather service said. A high temperature of 34 degrees, with a low of 16, was predicted Sunday, and a high of 32 and low of 19 was predicted for Monday.
Kennewick normally sees an average high temperature of 50 degrees and a low of 36 this time of year.