Significant smoke can still be seen in satellite imagery over Yakima, Benton, and Klickitat counties this morning. The Evans Canyon brush fire has burned 35,000 acres to date and is still active with no containment. Smoke has been causing Moderate to Unhealthy air in Yakima and nearby communities. Winds are expected to push some of that smoke north today, perhaps allowing some intermittent clear air for Yakima residents over the next couple days. However, the smoke has to go somewhere, thus intermittent Moderate to USG smoke is expected in communities like Ellensburg and Cle Elum this afternoon and tomorrow.
GOES image of smoke from Evans Canyon fire (Sept 3, 2020 - 8 am)
General winds will decrease over the Columbia Basin and the Columbia River Gorge for the next several days, bringing warm, dry weather through the Labor Day weekend and beyond. Early next week the pressure pattern will shift to bring gusty easterly winds to much of the west side. Fire danger will continue to rise and gusty easterly winds are expected on Labor Day.
In other news, smoke from California wildfires is expected to head north, and may cause surface smoke impacts in southwest Washington (e.g. Vancouver) on Friday. There is also some minimal fire behavior in Idaho, which could push a little smoke into SE WA (e.g. Asotin county) when winds shift, tonight and into Friday morning.