The National Weather Service in Portland has extended its air stagnation advisory for Clark County until Nov. 12.
The advisory was originally set to expire at 4 p.m. Wednesday, but a continuing lack of airflow has trapped smoke and other contaminants near the ground, according to the weather service.
Among the affected communities is Vancouver, Battle Ground, Ridgefield, Washougal, Yacolt and Amboy. The advisory also includes the Portland metro area and the Interstate 5 corridor in Cowlitz County.
An area forecast synopsis posted on the weather service’s website says residents should see less severe stagnant air conditions overall, but the south Willamette Valley in Oregon and the I-5 corridor in Southwest Washington “will probably see the least improvement.”