Smoke continues to hover overhead and the previous forecast still holds. As explained there the temperature inversion is still keeping the smoke at bay. We've hardly seen air quality deteriorating beyond Moderate anywhere in the state, or further upwind in Oregon for that matter.
There is fog in the Puget Sound lowlands and this will recur each morning through Sunday. Fog should not be confused with smoke. Here's an illustration of what's what as seen from above, but only an air quality monitor can distinguish between the two at ground level.
Things will stay that way and start to "improve" by Saturday night as a slight wind shift s-l-o-w-l-y disconnects us from the CA smoke late in the weekend. Models are persisting with the inversion in western WA so any residual smoke aloft wont mix down all that much. But inversions also lock in our own local emissions at the surface. Overall, we can expect:
- Good to Moderate air in much of the state
- Moderate or areas of Unhealthy for Sensitive Groups in the higher terrain of the Olympics and Cascades (hard to pin down what elevation the transition occurs).
- Saturday's sunset may not be as colorful
BTW the air quality monitoring data map at the top of this blog has been upgraded to show both the new EPA Fire/ Smoke map that incorporates corrected low-cost sensor data, and our 2-day PM2.5 forecast. Might take a moment to load. If you're using a mobile device, scroll to the bottom of this page and click "View web version" to see this.