The Puget Sound Clean Air Agency has called for a burn ban in Snohomish and Pierce Counties, as stagnant air is expected to result in poor air quality.

The lack of moving air through the region means pollution stays put. The stage 1 burn ban went into effect Friday at 2 p.m. Fireplaces are not allowed. Outdoor fires are also banned.

What’s allowed during a Stage 1 Burn Ban? Certified wood stoves, pellet stoves & gas/propane stoves are OK, but not fireplaces. Outdoor burning is always illegal. https://t.co/wDyTP4Qt3K pic.twitter.com/3LaDGJOjKy — PS Clean Air Agency (@pscleanair) December 8, 2017

Western Washington is familiar with such poor air quality, especially after last summer. Wildfire smoke from Oregon to Canada sent air quality plummeting for days.

In August, however, Erik Saganic with the Puget Sound Clean Air Agency told MyNorthwest that the poor summer air quality was mostly shocking to residents because it was lighter later into the night. This resulted in some stunning sunsets. In the winter, however, similar air quality is present, but people don’t notice it as much because it gets darker earlier.

“The levels we are seeing (in August) we do see on occasion in the winter months when the air gets stagnant and we have a lot of wood smoke from home heating,” Saganic said. “But we’re at home and it’s dark outside so you don’t see the smoke. Now it’s really visible in the summer and a lot of people are out and about. We’ll see that about 15-20 times in the winter. But to have it like this in the summer is really unique.”

Burn ban and poor air quality

The National Weather Service has also issued an Air Stagnation Advisory for the I-5 corridor through the Puget Sound region until Monday. A high pressure system is keeping the weather fairly calm, and in turn, is keeping the air quite still.

“We expect the high pressure system to continue to trap pollution at the ground level during this time,” the Puget Sound Clear Air Agency said in a statement. “The forecast shows periods where wind speeds may speed up occasionally, but we don’t expect these periods of wind to significantly improve air quality.”

Cold in the lowlands and warm in the mountains…must be an inversion! Learn more about this interesting weather phenomenon ongoing now and the impacts on air quality this upside down pattern has. https://t.co/UHWViQFQYC #wawx #seattle pic.twitter.com/bhQ1BbamFW — NWS Seattle (@NWSSeattle) December 8, 2017

Air Quality forecasts for Snohomish and Pierce Counties state that air ratings could go as high as 107 into Saturday (any rating above 100 is listed as “unhealthy for sensitive groups”). King County — located in between Snohomish and Pierce — is forecast to have moderate air quality over the weekend.