Where there’s smoke, there’s usually fire, they say.
Not quite, in the case of Seattle’s dose of campfire-scented haze.
The smoke that enveloped the region (almost entirely except for the upper reaches of the Cascades and the Olympics) didn’t come from any fires in Seattle or even in Washington state. Instead, north winds carried smoke south from a string of wildfires burning in British Columbia.
And thanks to a strong high pressure system “anchored” over Washington, the smoke isn’t likely to be carried off by other winds in the next few days, according to a Washington Smoke Information report.
That said, in a Thursday forecast, the National Weather Service predicted that smoke would clear out late Friday.
Seattle’s air quality was unhealthy Thursday morning, and similar conditions were reported across the state, according to the state Department of Ecology’s Air Quality Monitoring Network.
Flights bound for Sea-Tac on Thursday morning were delayed more than an hour due to low visibility from the smoke, according to an FAA status report.
Visibility at Sea-Tac was down to three miles at mid-afternoon, which was just a prelude to the official high temperature of 91 degrees.
The NWS said Tuesday night that smoke might reduce high temperatures by a few degrees from what had been forecast earlier in the week.
The smoke, it said, should reduce visibilities to three to five miles and perhaps as low as two miles in lower valleys.
Ventilation would be worse late at night and in the mornings but with the help of industrial air quality monitors it can change.
Read more: Hot and hazy: Smoke from B.C. fires will hang around Seattle