It’s only mid-October, but by this weekend, it’ll feel like mid-November.
Much colder air will invade Western Washington beginning Saturday, dropping our high temperatures to around 50 degrees—a mark not usually reached in Seattle until just before Thanksgiving.
The air will feel especially brisk when contrasted with today’s highs, which hit the mid 60s as warm air ahead of the rain boosted temperatures to above normal. Now, with precipitation falling throughout the metro area, we’ve cooled into the upper 50s—just the beginning of our downward trend in temperature.
Highs tomorrow will fall to around 55 degrees—a few shy of the average Oct. 19 high of 58—with another .30 inches of rain falling from Seattle to Everett as a Puget Sound Convergence Zone moves through. By nighttime, we’ll dry out and clear up a bit, allowing temperatures to lower into the mid 40s.
The colder air really makes itself known this weekend as a large upper level low—comprised of chilly air with Canadian origins—drops down from the northwest. Temperatures on both Saturday and Sunday will peak in the low 50s at best—remaining in the 40s a majority of the time. A high of 52 this weekend would make for Seattle’s coldest day since May 3, whereas a sub-50 degree reading would give us our biggest chill since April 5, when Sea-Tac only hit 49.
Heavy-coat weather aside, both Saturday and Sunday should actually turn out pretty decent, with none of the day-long rainy spells that we saw last weekend in store. Instead, both days will be bookended by partly sunny skies, with clouds and showers likely only during the afternoons. (It’ll be a different story in the Cascades, where wetter conditions will result in a few inches of snow at pass level by Sunday.)
The upper level low sticks with us into early next week, giving Seattle another pair of 50-degree days Monday and Tuesday as our November-like temperatures continue.
Just don’t get too fooled—Thanksgiving is still several weeks out.