Issued by Ranil Dhammapala, Washington State Dept. of Ecology. Air quality in most areas saw considerable improvement on Saturday. Clearing will continue through Sunday evening, but there could be areas in and around the Columbia Basin that experience smoke for a short time today.
A period of prolonged stagnation sets up through most of WA starting Monday, with winds being mainly terrain driven. Temperature inversions are expected to be strong but are forecast to break up during the day in most places. Yet with light and variable winds, pollutants will not disperse as well. While it is hard to pin down exact details for each community, in general most areas are likely to see air quality degraded to some extent. Communities close to smoldering fires are likely to be impacted throughout the day to varying degrees. Partial daytime clearing in most areas with the least clearing in sheltered valleys, seems to be a good bet.
Models are suggesting mildly offshore pressure gradients, which could push a little smoke over the Cascades into western WA over the next few days.
Please note that the Governor’s Office has issued a burn ban in eastern Washington: http://www.governor.wa.gov/news/news-view.asp pressRelease=1966&newsType=1