August 12, 2021

Forecast: August 12th, 2021

By Matthew Charchenko

While we lucked out with a relatively cool July, the heat has made its way back to Western Washington. Even though we wont be seeing temperatures as high as we did back in June, this heatwave will still be significant enough to prompt the NWS to issue an Excessive Heat Warning as temperatures climb into the mid to upper 90s across Western Washington.

These hot and dry conditions will also create high fire danger in the Cascades and the foothills, so be sure to adhere to local burn bans if you’re heading up into the mountains as any fire will spread quickly through all of our dry brush.

The current satellite picture shows another impact this heatwave will have…smoke. We have been lucky to stay relatively smoke free this summer while many major fires have been burning to our north, south, and east, but increasing offshore flow today will continue to bring smoke into the Puget Sound region.

Hazy skies over the next few days might limit high temperatures by a few degrees, but that will be at the cost of some reduction in air quality. As of right now the air quality is still in the green in Seattle but areas north and east have experienced reductions in quality. Fortunately, most of the smoke looks to stay just above the surface but some will still filter in through our mountain passes through the weekend. So expect some occasional reductions in air quality over the next few days into the moderate to unhealthy for sensitive groups categories.

Onshore flow will return on Sunday bringing cooler weather and even some rain next week which will help clear out the air making for much more comfortable conditions.

Reach forecaster Matthew Charchenko at theuwdawgcast@uw.edu and on Twitter @mcharchenko

THURSDAY AFTERNOON ATMOSPHERIC SMOKE	THURSDAY AFTERNOON NEAR SURFACE SMOKE