A white Christmas is a rarity in the greater Seattle area, but it’s not out of the question this year. A mix of snow and rain is expected in most places around the Puget Sound region. That could make for some treacherous driving conditions, says Ted Buehner with the Seattle office of the National Weather Service.
Snow Possible Friday
Buehner says a Pacific weather system is easing inland on Friday, bringing rain to the lowlands and snow up in the mountains. The some cooler air behind it will nudge snow levels below 1,000 feet Friday night and into early Saturday.
“So any lingering precipitation could fall as snow,” he said. “Most of it will fall in the Cascades and the foothills, but some lowland areas may get some flurries or light snow with light accumulation.”
Highs on Friday will be around 40 degrees, which is about 5 degrees below average for this time of year. Lows will drop close to freezing.
Clearer, Colder Saturday
On Christmas Eve, highs will be in the 35-40 degree range. Any lingering precipitation will come to an end and skies will clear up.
“So good flying weather for Santa, but he’s going to need to bundle up with chilly lows in the mid-20s to lower 30s,” Buehner said.
White Christmas Unlikely
Christmas Day looks dry and sunny, but cool, with highs only reaching 35-40. So the likelihood of a true white Christmas is slim. Buehner says that’s partly because the official definition of a "white Christmas" is when quite a bit of snow falls and sticks.
“Typically it’s one inch or more,” Buehner said. “And the last time we had a white Christmas here in Western Washington was back in December 2008. So, you look historically, it’s only 5 percent odds of having such a thing.”
Buehner says the mix of weather means you should be prepared for potentially treacherous conditions if you’re traveling from pretty much anywhere around the Northwest over the holiday weekend.
“If you’re flying out of Sea-Tac Airport today [Friday,] we’ve got a combination of the rain, low-level clouds and a north wind. That usually slows down the amount of flights in and out of the airport. So there may be some potential flight delays,” he said.
"Check with your airline," he advises.
If you’re on the road driving, Friday is the best day for traveling, Buehner says, with just rain coming down. Remember, however, that snow levels will be falling overnight. He says not much snow is expected.
“But combined with leftover moisture on the roads, freezing Saturday morning, plus any light snow could make for some slippery conditions,” Buehner said.
He says if you’re headed over the Cascades or up into the mountains, expect 3-7 inches of snowfall from Friday into Saturday. And he says east of the Cascades there will be a few inches of snow sticking around, with cooler temps: highs struggling to get to the freezing point and lows in the teens and twenties.
“The bottom line is, wherever you’re going, be prepared for winter driving conditions,” Buehner said.
To hear the forecast along with Ted’s discussion of some of the weather highlights from 2016, you can click on the “play” icon at the top of this post.
Guest commentator Ted Buehner is the Warning Coordination Meteorologist for the National Weather Service in Seattle.
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.