Note: Some users might notice intermittent discrepancies in colors shown on the map of air quality monitors above, and those reported on the Department of Ecology's official page. This is because Ecology believes their method of calculating the air quality category (i.e. “Good”, “Moderate”, Unhealthy” etc) is more protective of public health in Washington. If in doubt as to which better represents public health risk, use the more stringent of the two (i.e. the map showing worse air quality).
Monday, July 31, 2017
Brace yourselves, smoke is on its way
Statewide air quality is mostly Good at present, except for the Methow valley and Darrington. Previous forecast for the Methow is expected to remain valid for the next few days.
Smoke from the Suiattle fire has caused air in Darrington to degrade to Unhealthy for Sensitive Groups. Some relief is expected during the daytime hours today but smoke will likely remain trapped in the valleys overnight and worsen when the morning inversion breaks. Air quality is expected to vary between Moderate and Unhealthy over the next few days, depending on fire activity.
The big story is that the north winds are transporting smoke from British Columbia wildfires into northern Washington. Satellites show that large plumes have already crossed the northern border and will likely impact communities in Okanogan and Whatcom counties between now and Wednesday. Expect air quality to vary between Good and Unhealthy for Sensitive Groups. Some models (see forward trajectories at different heights) suggest this smoke could push all the way down to King County by late Tuesday. We will be watching this closely.
Forecast models show smoke draining further into central WA by mid- week, so communities along the Okanogan river valley should brace for Moderate or poorer air.
Please take a look at the "Smoke and Health" section of this blog, which provides several resources to protect yourself from the harmful effects of smoke.
On the bright side, smoke plumes that remain aloft will offer a little relief from the oppressive heat by providing a thin sun shield that lowers temperatures a degree or two. And they will cause pretty sunsets.
Winds turn easterly from Wednesday onward and while this might reduce the BC smoke faucet, it will likely transport smoke from western Montana to eastern Washington. More on this in the next update.