Are you dreaming of a white Christmas? Keep dreaming, if you’re in western Washington. A couple of feet of snow fell on local ski areas earlier this week, but that’s pretty much over for now. And there’s little prospect of much holiday snow accumulation in the lowlands.
The mountains can be so alluring this time of year, with views of snow-covered peaks all around us. Yet it can be hard to find good conditions for cold-weather fun such as skiing or snowboarding.
Why is the snow quality so poor here, so much of the time?
“The problem is, we do get quite a bit of snow in the Cascades, but we also get rain up in the mountains and we also have warm periods” said KNKX weather expert Cliff Mass, a professor of atmospheric sciences at the University of Washington.
“We’re not living in a place that the mountains are at really high altitudes or where the temperatures are uniformly cold. To get that you have to go to higher peaks in the Colorado Rockies or something like that,” he says.
We do get quite a bit of snow here in winter – we can have dumps that range from half a foot to even several feet of snow, pretty regularly.
“And initially, it might not be bad snow, it could actually be pretty fluffy powdery stuff, initially,” Mass said. “But, inevitably, we’ll get a period where the temperatures will warm up, we’ll have an atmospheric river come in and the freezing level will rise to 9,000 or 10,000 feet. And then rain falls on the snow.”
‘Cascade Concrete’ Is The Norm
When rain falls on the snow, bad things happen, says Mass.
“The rain goes into the snow. It melts it a little bit, but more importantly, inside the snow, the temperatures are relatively cool – below freezing,” he said.
So the water goes into the snow pack and then re-freezes inside it.
“And so, we go from this nice powdery, fluffy stuff to something that hardens up very rapidly into what’s often called ‘Cascade concrete.’”
Mass says the problem is basically just that western Washington temperatures are always pretty much on the edge, even in the mountains. And that’s due to the influence of the warm ocean that’s always looming upstream of us as weather systems come in.
For Best Skiing Conditions, Look For Highest Elevation
This temperature problem is generally known to be especially bad at Washington’s Snoqualmie Pass and Steven’s Pass ski areas and only slightly better at Crystal Mountain.
“A lot of it is elevation,” Mass says. “Snoqualmie is marginal, let’s face it. The bases are only a little over 3,000 feet, a lot of the runs go up to maybe 4,000 feet. It’s quite low. And so you get rain all the time. I’ve skied up there plenty and I can’t tell you how many times I’ve been on the lifts and it starts raining on me,” he said.
Stevens is better, he says, because it’s 1,000 feet higher, so they tend to get slightly better snow quality.
“But you have to go to the places which have much higher runs – and Crystal is a good example of that. Whistler has higher runs too,” he says.
“So these places have cold temperatures holding in more uniformly and so they tend to get less of the Cascade Concrete.”
Where To Go For A Winter Wonderland
Mass says if you’re looking for reliable snow, you have to go east of the Cascade Crest.
“So you go to Mission Ridge or you go to one of the ski areas that are in British Columbia, further inland. Those are more reliable, Idaho is more reliable. Certainly, Utah is more reliable,” he said.
And he says you can usually count on good conditions at higher elevations in the BC Cascades, such as the higher runs at Whistler.
“Those are more reliable. You cannot depend on Snoqualmie Pass,” he said, adding that he thinks it’s low enough that it probably won’t be able to offer any skiing at all under global warming from climate change in the region over the next 50 years.
“There won’t be any ski opportunities at Snoqualmie Pass. I think it’ll just be too warm and too low,” Mass said.
When Not To Go Out In Any Snow
With snow conditions so marginal so much of the time, Mass says there are times when it’s truly best to stay at home.
“The big danger is after we’ve had a period of heavy snow … and then we get into a rapid warm-up, like when we have an atmospheric river,” Mass said.
Also known as the ‘Pineapple Express,’ these atmospheric river events are when moisture comes up in a narrow band from the region around Hawaii.
“We get warm rain falling on the snow. The snow gets very heavy. And so in places where there’s a lot of slopes, you can get failures and avalanches coming down to lower elevations,” Mass said. “So that’s something to worry about.”
A good place to check conditions before you head out is the Washington Ski Report.
Weather with Cliff Mass airs at 9:02 a.m. Friday, right after 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 podcasts of Weather with Cliff Mass shows, via iTunes or Google Play.