A Very Snowy Week Ahead for the Cascades

A Very Snowy Week Ahead for the Cascades

When I was little, I remember how the Summit at Snoqualmie would always put out a “Photo of the Day,” chronicling the weather conditions each day up on the mountain. Now, they have an Instagram and take photos whenever they feel like it, and while I guess it serves the same purpose as the “Photo of the Day,” it was always nice for each day to have it’s own special photo so that boring days wouldn’t feel left out. Now, it’s also quite nostalgic for me, as it reminds me of a time before we had our faces buried in our smart phones.

Anyway, I’m going on this little tangent because occasionally, those Photos of the Day would feature somebody skiing during Thanksgiving at Summit West. I remember such photos during the seasons of 2005-2006 and 2006-2007, as we had 88 and 111 inches of snow, respectively, during those months. Since I was just discovering meteorology resources on the internet at this time, I soon became under the impression that the ski season was well underway by most Thanksgivings. That turned out not been the case, as our last Thanksgiving opening likely occurred sometime between 2009-2011 as we got ~80 inches of November snow during those months. Since then, our Thanksgiving amounts have been downright pitiful, with an average of less than 2 feet falling from Novembers 2012-2016.

But we’re already breaking the mold. Timberline Lodge on Mt. Hood has already picked up an astounding 127″ of snow this and is open 7 days a week. Crystal Mountain says there’s a “really good chance” they will be open on next Friday, November 17, as does the Summit at Snoqualmie. With any luck, these and other resorts will be open for winter sports enthusiasts to burn off some calories, pre or post (or perhaps during) gravy.

To start, let’s do what any “in-the-know” forecaster does: take a peek at the 500 hPa chart to see the general flow in the upper-levels of the atmosphere. Right now, we have a giant, blocking ridge over Alaska, creating a large trough in the Eastern Pacific.

500 hectopascal height anomalies (compared to 1981-2010 climatology)
500 hectopascal height anomalies (compared to 1981-2010 climatology)

With a weak ridge just offshore and no real storm track to speak of, we are not currently in a pattern conducive to mountain snow. But that will change as this ridge moves inland and the trough east of the ridge in the Gulf of Alaska dives southward, giving cool, southwesterly flow into the region.

This system could drop modest amounts ranging from 3-6 inches in most places, but because are in southwesterly flow, snow totals will still remain in the 3,000 foot range and Snoqualmie Pass will see wet snow or a rain/snow mix. But thankfully, we transition to a much more favorable mountain snow pattern towards the middle of next week, with strong northwesterly flow into the region. Northwesterly flow is fantastic for mountain snow because it is cool and has a fair amount of moisture, and when this air slams into the Cascades and rises, we can get some hefty snow totals as a result.

Take a look at the 72-hour totals from 4 pm Wednesday to 4 pm Saturday. Heaps of snow over the Cascades, particularly by the famous Mt. Baker Ski Resort. Snoqualmie Pass will get less, but don’t count them out; temperatures there are often lower due to cooler air from the Columbia Basin flowing through the pass. This should definitely give enough snow to open up Crystal, Mt. Baker, Summit West at Snoqualmie, and most of the other ski resorts around the area.

72-hour snowfall ending 04:00 pm PST, Fri 17 Nov 2017
Credit: University of Washington Atmospheric Sciences

To sum things up, the pattern will turn increasingly favorable for snow over the next couple days, and by the middle/end of next week, we’ll be in a textbook pattern for mountain snow and many ski resorts should have enough snow to open for limited operations. I think it’s safe to say that you’ll be able to get in some Turkey Day turns at most places. And finally, the Summit at Snoqualmie should reinstate their disciplined “Photo of the Day” program on their website for smart-phone-challenged folks like me and to make sure no individual ski day feels left behind.

Have a great Friday and weekend, and keep those snowy thoughts coming!
Charlie

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