Outlook: good air quality and localized smoke impacts

 The majority of the state continues to experience good air quality and low fire danger. A very clear satellite image from this morning--only the smoke plumes from the Airplane Lake Fire and agricultural burning in SE WA are visible, as well as smoke in Oregon):

The Airplane Lake Fire continues to cause intermittent smoke impacts around the Lake Wenatchee area and into the Wenatchee Valley, impacting the communities of Leavenworth, Cashmere, and Wenatchee. These intermittent smoke impacts will continue until the next significant precipitation event. There is potential for light smoke impacts today in East Snohomish County, but winds from the west this weekend will push any smoke east of the Cascades.

Across the rest of the state, fires in the Cowlitz Complex comprise almost 700 acres and are partially contained. Smoke from these fires is not expected to impact nearby communities. The Sourdough Fire continues to intermittently impact areas close to the fire in the Ross Lake National Recreation Area. There are also a few fires currently burning in the Olympics that were ignited two weeks ago by lightning strikes. Smoke from these fires (including the Eagle Point and Low Divide Fires) may intermittently impact Port Angeles and higher-elevation areas around Port Angeles. 

Weekend outlook: warm and dry conditions are forecasted for the weekend, but we're not expecting any significant new fire activity. Increased smoke from any local fires and prescribed burning may cause localized moderate air quality levels. Forecasted high winds across Central and Eastern Washington along with the dry conditions can lead to rapid fire spread; please continue to recreate responsibly.

-----------------------------------------------------------------------------------------------------------------------------

Taking a look back at our air quality this wildfire season, below is a plot of observed daily air quality levels for each day in each county in the state where there is an air quality monitor. Each row corresponds to the daily average at the most impacted monitor observed in each county on a given day. The major events we saw this wildfire season are highlighted--smoke from the Alberta fires in May, smoke from the Cascades and Southern BC fires in August as well as local fires in Spokane, and smoke from fireworks on the 4th of July. 

And how does this season compare to previous years? If we look at a timeseries of PM2.5 concentrations averaged across the state during wildfire seasons over the past 10 years, this year we saw smoke impacts in August, which is pretty typical. In previous years, easterly wind events have contributed to large smoke events in September and October. While it's only mid-September, that seems increasingly unlikely to occur this year, thanks to the recent cool temperatures and precipitation in the region and the low number of active fires in the Cascades.