Get Ready: A Cold Weekend Could Lead To Snow In Puget Sound Lowlands

Dec 2, 2016

It’s time to get out your winter hats and gloves. The coldest temperatures of the year so far are in the forecast this weekend, says knkx weather expert Cliff Mass. There’s also a good chance of lowland snow hitting the Puget Sound region starting Sunday night.

“We have a lot of certainty that we will have a very cold period, at least compared to anything we’ve had in the last year,” Mass said. “But the big question is snow.”

Mountain Snow Already Here

Mass says there’s already been a tremendous amount of snow falling in the mountains this past week, as temperatures finally got cold enough aloft.

“Even Snoqualmie Pass had a foot [of snow],” Mass said. Stevens Pass got two feet and Mt Baker had three or four. “So, we’ve had an amazing amount of snow up in the mountains and they’re going to get a lot more before the week’s up.”

But what people really want to know is how much snow is going to fall in the lowlands.

Rainy Weekend Ahead

Mass says the weekend won’t be too snowy, at least initially. “A weak front is moving through,” he said of Friday, “so we’re having some rain. But temperatures only getting up into the upper 40s, nothing very serious.”

He says Saturday will be a mellower day, with maybe some clouds and a few showers, but nothing much.

Snow Possible Starting Late Sunday  

The big issue will be later Saturday night and Sunday morning, Mass says. when an extremely strong Pacific front comes through, bringing in very cold air coming from the northwest.

“So we will not only have rain on Sunday morning, but you’ll notice the temperatures falling,” Mass said. “And in fact, I don’t expect the temperatures on Sunday to get above the mid-40s, maybe 43 - 44, much colder than we’ve had. And so, as we get into Monday, we will be getting air that is cold enough to bring snow down to low elevations.”

He says the big question at that point is moisture – and whether there will be enough of it coming in to produce much of the white stuff.

Mass says there’s a range of possibilities, from just a few flurries with nothing sticking to as much as an inch or two of snow.

Based on the ensemble of numerical models he consulted to predict the forecast, Mass wagered a guess that there will be some snow, but not much.

“A dusting on Monday,” Mass said. “Some places may get an inch. And then 3 to 5 inches in the heavier locations of the lowlands on Wednesday-Thursday, but I think most of the places near sea level will only maybe an inch or something like that.”

But this was only an educated guess. We will know more next week.

To hear the forecast along with Cliff’s description of how meteorologists use ensemble forecast modeling, 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.