The National Weather Service has issued a stagnant air advisory for Western Washington through noon Wednesday, the result of a high pressure system that is sitting stationary over the region.
"The air is not moving like it's supposed to," said meteorologist Steve Reedy on Sunday, and that can lead to a build up of pollutants in the form of car exhaust and smoke from outdoor burning.
"Air quality will gradually degrade and that's what we're concerned about," he said.
People with respiratory illness should follow their physician's advice for dealing with high levels of air pollution during periods of stagnant air, the National Weather Service advisory reads.
State air quality agencies highly recommend that no outdoor burning occur and that residential wood burning devices be limited as much as possible, according to the advisory.
Above an elevation of 1,500 feet, though, it's a different weather story.
"If you want to see blue skies, go to the mountains," Reedy said.
