Cliff Mass: Wildfire smoke hanging over region ‘will be radically better tomorrow’
Aug 21, 2023, 3:44 PM | Updated: 5:11 pm

Smoke in Western Washington (KIRO 7)
(KIRO 7)
Fires throughout the Pacific Northwest have caused unhealthy air quality levels as smoke descended upon the region last weekend.
The fires in both Eastern Washington and Canada are expected to last a few more days.
More on WA’s wildfire smoke: Smoke should clear from Seattle skies by Tuesday
“When should we expect clean air again?” KTTH host Jason Rantz asked University of Washington (UW) Atmospheric Sciences Professor Cliff Mass.
“Tuesday in the morning,” Mass answered. “It was better and, along the coast, there was no smoke. At low levels, it was much better. At the surface, there was some smoke, still a lot this morning, but it got much better at the surface. It’s way better over much of Western Washington, so we can see the sensors that tell us how much particulate matters there. And it really improved during the day.”
As of 3 p.m. Monday, the Air Quality Index measured at 96 in Seattle, which is in the “Moderate” range. According to AirNow.gov, that range means, “If you are unusually sensitive to particle pollution, consider reducing your activity level to shorten the amount of time you are active outdoors.”
The PM2.5 concentration — the measurement of fine inhalable particles — in Seattle is six times the World Health Organization’s (WHO) annual air quality guideline value for exposure, IQAir reports.
PM2.5, or particulate matter 2.5, refers to tiny particles or droplets in the air that are 2.5 microns or less in width. The largest PM2.5 particles are about 30 times smaller than a human hair.
Mass said the ability to predict the generation and movement of wildfire smoke has become “extraordinarily good” in recent years, alongside developing technology that helps predict the winds that can initiate and expand wildfires.
“We knew days ahead of time that this was going to happen,” Mass said. “It was no surprise. We have these smoke models now that are extraordinarily accurate. We knew that the winds were going to switch and some of the smoke in British Columbia was going to flood us. That’s what happened. And we have the models for the future. It looks like it’s going to get progressively better tonight, and will be radically better tomorrow. I think we’re in a substantially improving trend.
“The only thing we’re watching right now is Thursday,” Mass continued. “Thursday is going to warm up again. Not as hot as it’s been, but it will get into the lower 80s with maybe a little smoke, but nothing like what happened on Sunday.”
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Smoke concerns on Thursday directly relate to the Airplane Lake Fire in Chelan County, which has now burned approximately 1,445 acres as of this reporting with 0% containment, according to The Washington Department of Natural Resources (DNR). According to KOMO News on Friday, the fire is about 22 miles northwest of Leavenworth.
“I’m still pretty optimistic. We’ve had a number of fires in eastern Washington, but they’ve been mainly grass fires, and grass fires tend to burn out very rapidly,” Mass said. “The big smoke producers that we worry about is British Columbia with some of the forest burning. That’s the real smoke producer. As long as the air is not coming from British Columbia, we’re going to be in pretty good shape.”
Listen to the Jason Rantz Show weekday afternoons from 3-6 p.m. on KTTH 770 AM (or HD Radio 97.3 FM HD-Channel 3). Subscribe to the podcast here.