Heat and Some Smoke in Eastern WA

After a cooldown earlier this week, major to extreme heat has returned to eastern Washington. Temperatures will soar into the triple digits today with daily record highs possible across many locations east of the Cascades, prompting the National Weather Service to issue an Excessive Heat Warning, valid until 8pm Saturday. While the heat should ease somewhat by Sunday, above normal temperatures are likely to continue through at least the middle of next week across the state. 

Active large fires such as the Retreat Fire near Yakima will respond to this heat and are likely to see increased fire behavior and smoke production today through the weekend. Air quality is already MODERATE across much of eastern WA with UNHEALTHY values in localized areas closer to active fires. As a result, an Air Quality Alert remains in effect across all of Okanogan, Ferry, and Yakima Counties as well as the Colville and Yakima Reservations, until further notice. However, due to a reduction in smoke in localized areas, the Air Quality Alert has ended for Chelan and Asotin counties. Skies are also hazy in western WA due to smoke aloft, but surface air quality is expected to remain in the GOOD category. 

A star helicopter on the Retreat Fire, west of Yakima. August 1, 2024. Image via InciWeb. 

Looking ahead into next week the outlook is largely the same for the eastern half of the state, with continued MODERATE air quality impacts at times due to westerly winds pushing smoke from active fires off to the east. Additionally it's worth mentioning that, while uncertain, there is a possibility of isolated to scattered lightning strikes across the eastern half of the state today through Tuesday, which could bring isolated new fire ignitions and new sources of smoke. That being said, a widespread dry lightning event is not expected.

After that, we're watching for a possible wind shift out of the north around Wed-Thurs next week which could bring more significant smoke into different communities than we've seen lately. At this time, however, there are no obvious smoke concerns in the forecast for areas west of the Cascades.