The cold, dry air that’s been pouring into the Northwest and keeping temps well below freezing is coming to an end this weekend. But before the Arctic air completes its exit and things warm up all the way, there’s a possibility of snow in many areas, says knkx weather expert Cliff Mass.
“We have to get through a bit of cold for the next day or two,” said Mass, a professor of atmospheric sciences at the University of Washington.
Very Cold Friday Morning
He says Friday dawned with extremely low temperatures, especially in the eastern suburbs of Seattle, where some places saw the mercury dipping as low as the mid-teens.
”So this is unusually cold air that’s been over us. And that’s going to hold in for at least another day,” Mass said.
He says Friday will bring one last sunny day to the region, with cool, dry air. But he says temperatures will probably reach the upper 30s.
“So a little bit warmer; the air’s been warming up a bit aloft.”
Transition Late Saturday
Saturday will start relatively clear, but then a weak weather system will move in toward the coast during the later morning or early afternoon, bringing increasing clouds with it. Mass says temperatures will probably get up into the mid- to upper 30s again.
“But now we get into the difficult part. As the system approaches, precipitation will be associated with it. It’s going to be cold enough, initially, for there to be some light snow in certain areas before it turns over,” he said.
Mass says the areas with the greatest chance of snow are from Tacoma southward towards the Kitsap Peninsula and Southwest Washington. And there’s also a chance to the north in the higher elevations around Everett and up towards Northwest Washington. He says don’t be surprised to see a little bit of light snow developing later in the afternoon or evening on Saturday.
“There’s not going to be a lot, but there could be a little bit,” Mass said. “Then as warmer air floods into the region later on Saturday night [and] on Sunday, I think we’re going to see a turnover to rain.“
Warmer And Wetter Sunday
Mass says a stronger disturbance will come in on Sunday, bringing predominantly rain with it and temperatures likely reaching 40 or even the low 40s.
“Except maybe a few cold pockets, there may be a few flurries initially,” he said. “So I think we’ll see a warm up on Sunday … and a transition to rain, everywhere.”
He says that should mark the end of the cold spell here for a while, with the wetter pattern settling in and sticking around on Monday and Tuesday.
“So, we’ve had this extended period of well below normal temperatures and very dry conditions and I think we can see the end of it starting later on Saturday,” Mass said.
To hear the forecast along with Cliff’s discussion of how dry this cold spell has been and what other effects that has had on the local weather, including high winds in some places, you can click on the “play” icon at the top of this post.
The weekly knkx feature 'Weather with Cliff Mass’ airs every Friday at 9 a.m. immediately following ‘BirdNote’, and twice on Friday afternoons during ‘All Things Considered’. The feature is hosted by knkx environment reporter Bellamy Pailthorp. Cliff Mass is a University of Washington professor of atmospheric sciences, a renowned Seattle weather prognosticator, and a popular weather blogger. You can also subscribe to a podcast of ‘Weather with Cliff Mass’ shows.