Smoke from the Bolt Fire enters Western Washington

A relatively dense plume of narrow smoke from the Bolt Fire has swept into western Washington over the past few days.

And today could be the worst day of this period.

The 11 a.m. surface air quality network operated by Purple Air shows smoky air (red being the worst) moving west from the Steven Pass freeway to Everett and north of Seattle. I can smell the smoke here at UW.

This morning’s high-resolution visible satellite image clearly shows a plume of smoke passing through the relatively narrow Skykomish River valley and spreading out as it hits the lowlands.

Near sunrise this morning, plumes of smoke are clearly seen north by the Seattle PanCam.

Although not spreading horizontally, the Bolt Fire was still smoldering and burning inside, producing significant smoke, evident from the WSDOT cams on Route 2.

Meteorology is interesting.

Cool air produced by longer nights escapes into river valleys (like Skykomish) and then spews out into the lowlands, pumping smoke into densely populated areas each morning (see graph of particulate matter). in the air above Monroe, WA, days after days).

The meteorological “problem” is that we currently have a very weak pressure profile, with little clean shore inflow (see weather map for this morning, showing sea level pressure).

Tuesday won’t be much better, but the pressure pattern will change Wednesday afternoon, with more inshore and northwesterly flows moving in.