Today is a PinPoint Alert Day and a big turning point—not only because this will likely be the hottest day of the year so far, but because the heat is setting the stage for a much different weather pattern later today. As temperatures climb well into the 90s, increasing clouds, hazy skies, and the chance for thunderstorms tonight have prompted a Red Flag Warning for parts of Western Washington, where dry lightning could spark new wildfires.
Yesterday’s highs reached the upper 80s to mid-90s, and today will be even hotter. Expect upper 80s to upper 90s from Everett south, with communities south of Seattle—including Chehalis—having a chance to reach 100 degrees if the clouds arrive late enough. For many of us, this will end up being the hottest day we’ve seen so far this year.
You’ll also notice haze overhead today. Air quality is generally running in the moderate range across Western Washington, with pockets of “unhealthy for sensitive groups” near the Canadian border. Air quality remains much worse east of the Cascades, but as onshore flow begins to develop later today, we should slowly start to see conditions improve.
The bigger change arrives this afternoon and tonight. Clouds will steadily increase from the south as the remnants of former Tropical Storm Elida move closer to the Pacific Northwest. While this system has lost its tropical characteristics, it’s bringing enough atmospheric lift to trigger a few showers and isolated thunderstorms. The tricky thing today is: will the cloud cover impact temps? We’ll have to watch it closely.
The first chance for showers and thunderstorms develops this evening, mainly from Olympia south and into the south Cascades. Overnight and into Thursday morning, a few showers or isolated thunderstorms could spread farther north across Western Washington. Not everyone will see rain, but any storm that develops could produce lightning with very little rainfall.
That’s why a Red Flag Warning is in effect from about I-90 south through the Cascades and into parts of the South Sound. With vegetation extremely dry, even a few lightning strikes could ignite new fires if rain doesn’t accompany them.
The good news is this changing weather pattern also brings relief from the heat. By Thursday, highs fall back to around 80 degrees in Seattle with noticeably fresher air and improving air quality. Gusty winds east of the Cascades will keep fire danger elevated there, but for Western Washington it’ll feel much more comfortable.
Friday looks even better, with morning clouds giving way to afternoon sunshine and highs mainly in the 60s along the coast and north, with 70s to lower 80s elsewhere. Another weak system may bring more clouds Saturday with just a slight chance of showers, while Sunday currently looks like the better opportunity for more widespread showers.