"Smoke will remain in the region, and will cause air quality to reach unhealthy levels at times through Friday morning".
Unhealthy: People with respiratory or heart disease, the elderly, and children should avoid any outdoor activity; everyone else should avoid prolonged exertion. Smoke from British Columbia and the Cascades is continuing to build in the Puget Sound region today.
Around noon on Wednesday, the Environmental Protection Agency reported that Seattle's air-quality index was at 171 (unhealthy) while in China, where air pollution is a persistent, major health threat, the Beijing U.S. Embassy Real-time Air Quality Index was at 38 (good), KIRO reported. A high pressure system is pushing upper-level wildfire smoke down.
Still, experts say that relief is on its way.
But air quality may diminish again on Sunday when the onshore flow will be cut off, according to Allard.
On Saturday, the regional district cancelled a previous air quality advisory after some clean marine air swept through clearing last week's smoke away.
Smoky conditions have become so prevalent during wildfire season in the Northwest, there is even a blog dedicated to it.
Air quality in other parts of the state, like The Dalles and the Medford area, are also listed as unhealthy by the DEQ.
The agency adds that air quality is expected to be poor throughout the week as well.
Saxton said it would require a combination of changing wind patterns, rain and wildfire activity for skies to clear. "If you can be indoors where you get some filtered air, that's what you want to do".
"This is unusual for this summer for us", said Craig Kenworthy, director of the Puget Sound Clean Air Agency.