Updated Sunday 11:25 p.m.
Northwest blue tarp campers, rejoice! Those of you with outdoor camping and hiking trips probably enjoyed the quiet weather respite Sunday. Compared to our cool and soggy Saturday, the mid-day of the long holiday weekend was dry and mild. After a few lingering early sprinkles, partly sunny skies carried us back to about 70 degrees in downtown Seattle, making for a banner day at Bumbershoot, too.
Another disturbance is approaching our coastline tonight, but it's a weak one. Most of it will fall apart on impact with Western Washington, but we'll still snag a little bit of light rain out of the increasing overcast. The spots with the best chance at pulling down some precip include the coast, Cascades, and cities closer to the B.C. border. Most of us will see just a few early sprinkles, and lows on Labor Day will settle into the low to mid 50s. With partial afternoon clearing and just a few leftover showers, afternoon highs should kick back into the low to middle 70s for the final day of the holiday trio.
Tuesday is back-to-work, and for some local school districts, it will be the first day back-to-school. Mother Nature will cooperate by bringing back that 'fall feeling', as our first September storm ambles into the area. We'll see increasing rain through Western Washington by mid-day, and highs will struggle to get out of the 60s again. Some of the late day showers could even include some thunder, lightning or hail--added excited for that first day back on campus!
A few more showers will fall on Wednesday, and thereafter, summer makes a major comeback in Puget Sound. High pressure aloft combined with a growing west coast thermal trough will clear the clouds out and push the mercury up. Sunshine and 70s take over by Thursday, with many of us at or above 80 degrees both Friday and Saturday. Onshore flow from the ocean Sunday will allow for that cool, moist Pacific air to chip away at the heat by the second half of the weekend.
In the meantime, enjoy the rest of THIS weekend, and have a safe and happy Labor Day!
Meteorologist Shannon O'Donnell
The KOMO4 Forecast Team