Tuesday, August 15, 2023

Critical Fire Weather and Active Fires in North Cascades Increase Smoke Production this Week

Westside Smoke Relief Tomorrow, Eastside Impacts Increase

Unfortunately, our hot and dry weather has led to increased activity on several fires in the Northern Cascades. Remote weather stations near the Sourdough Fire topped out at 100 F yesterday afternoon and the heat is only expected to increase today. Critical fire weather will continue for the next few days. Hot and dry conditions will persist in the interior through Friday, while strong westerly winds will impact the Cascades this afternoon and all of Eastern Washington on Thursday. With all these threats, resources are spread thin, so practice fire safety to keep the workload on our firefighting teams as low as possible!

Currently most smoke in Washington is coming from the Sourdough Fire and the Dome Peak Fire, which is located in mountainous terrain north of Glacier Peak. Dome Peak was ignited in the same lightning storm as Sourdough and remained quiet until the hot weather this week allowed it to start flaming. There is also some smoke entering the state from fires in southern British Columbia and the Idaho panhandle. An Air Quality Alert is being issued for Chelan and Okanogan counties that will extend through Friday.

The Sourdough Fire continues to burn in heavy timber along State Route 20 with significant growth potential forecasted for the rest of the week. The Dome Peak Fire northeast of Glacier Peak recently sparked up and is showing no signs of calming down through the rest of the week. Both fires are located near the Cascade Crest, so the wind direction will be very important in determining which side of the mountains see the most smoke.

Today will be the last day of significant smoke impacts for most of Western Washington. Later today, onshore flow will resume which will push most smoke east of the Cascade crest. This will cause smoke to flow down mountain valleys on the Eastern Slopes such as the Methow and down Lake Chelan. The Methow Valley will be an area of concern for the rest of the week with up to Unhealthy air quality through Friday. Areas near existing fires like Newhalem and Stehekin will see Very Unhealthy to Hazardous conditions, especially at night, when smoke gets trapped near the surface. Chelan could see up to Unhealthy for Sensitive Groups for the rest of the week as well, while Moderate impacts are expected for Waterville, Darrington, and Concrete. Below is a depiction of smoke transport for the next 24-72 hrs.

Another concern is northerly winds through the Okanogan Valley channeling smoke from British Columbia towards the Columbia Basin overnight tonight and tomorrow. Similarly, smoke from the Ridge Creek fire in Idaho may be channeled west towards Spokane. These events will result in Moderate air quality for the Omak and Spokane areas through Wednesday, though impacts should subside for Thursday and Friday.

With mid and upper-level winds out of the west for the remainder of the week, elevated smoke will be visible across most of eastern Washington. As always, critical fire weather greatly increases the likelihood of new fires popping up statewide. If any new fires do crop up, smoke will be pushed east, so Eastern Washington will be primarily impacted. 

Jared McGlothlin
Wildfire Meteorology
Washington Department of Natural Resources


  1. New fire popping up too. Blue Lake fire. They are sending A LOT of tankers there. Seems to be in a horrible spot. Could be very bad.

    1. Yes, the Blue Lake Fire will also contribute to smoke in the Chelan/Methow Valley areas.

  2. Quick Update:
    Airplane Lake Fire (south of Dome Peak) became much more active yesterday evening, this will extend smoke impacts southeastward toward Leavenworth and Wenatchee the next several days.

    Smaller fires in the North Cascades (Blue Lake and Kindy Creek) will also contribute to smoke but will generally follow the same transport patterns as Sourdough/Dome Peak

    The easternmost fire in BC also burned very intensely yesterday, increasing the smoke impacts for the Okanogan Valley for today and tomorrow morning.

    1. dome peak reports just went from 30 acres to 770... not great

  3. Scheduled to hike the PCT from Stevens Pass northbound this Saturday (8/19)
    Safe? How far north of Stevens on the PCT is the trail smoke free?

    Thanks! Will

    1. While that area is smoke-free now, there is a high likelihood that Saturday will see winds shift and smoke pushed into the Cascades as far south as Kittitas County.


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