Summary
A very strong and cold storm is at the doorstep. Deep low density snow is headed for a large swath of the Western US, starting tonight and lasting for the next several days. Overall, this will be an unusually cold storm, with snow levels much lower than normal. The two most important aspects of this storm are this cold air and the available moisture. The two image below show that.
First, we have the precipitable water anomaly map. This shows, compared to normal, how much water is available in the atmosphere to fall out of the sky as snow. Some values of 100-200% above normal.
This isn't all that surprising, considering this storm is tapping moisture via an atmospheric river, as seen below.
Finally, this storm is pulling some unusually cold air down from the Arctic. See below for the arctic air getting down into the Pacific Northwest.
Resorts in Washington, Oregon and California will eclipse two feet from this storm, while Wyoming and Idaho will see 1-2 feet. Utah will add another 12-20\", while much of Montana and Colorado will end up around a foot as well. Some resorts will see totals even great than two feet as well. A second storm will follow with not much of a break, with snow picking back up on Friday in the Northwest.
Below is the GFS snowfall for the next 5 days.
Announcement
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Short Term Forecast
With a big storm like this followed by another later in the week, we will take it one storm at a time, as well as by state/region.
Washington/Oregon
The storm on our doorstop for Washington and Oregon is pretty special. It has a lot of cold air and ample moisture, with really low snow levels and excellent quality snow on tap. In the Washington Cascades, snow levels will be down to sea level except for Crystal and farther south, where they will be below 500 feet. In Oregon, snow levels will be a little bit higher, but still should be below 1500 ft. The cold front will arrive Wednesday morning in northern Washington, and progress south throughout the day. Winds will be blowing with this storm, but it doesn't look like any snow ruining type of stuff.
Snow is getting underway this Tuesday evening in Washington, as heavy snow spreads across the Cascades. Northern Oregon should see snow starting this evening as well. Also, a friendly reminder that the Indy Ski Pass prices go up after November 30! Mt. Hood Meadows is a newly added mountain to the Indy Pass and they had a powder Opening Day on Tuesday! Wednesday will be a powder Opening Day at Mt. Bachelor, Oregon. In Washington, the heaviest snow will be overnight Tuesday, while Oregon sees the most intense snowfall during the daytime hours on Wednesday. In Washington, light to moderate snow will continue during the day on Wednesday in the North, while moderate to heavy snow will continue in the South. Snow showers will linger into Thursday as well. Moderate snow will continue into Thursday for the Oregon Cascades as well, before becoming more showery Thursday night.
Winds will initially be from the SSW for Washington, and a little more SW for Oregon. This is great for Baker and good for Crystal, and a little less ideal for Stevens an Snoqualmie. Still, the overall storm setup, available moisture, and cold air will bring deep totals to all the Cascade resorts in Washington. The wind direction is favorable for deep snow in Oregon as well. Ok, let's get into storm totals.
As mentioned, the biggest thump of snow for Washington well be Tuesday night into Wednesday, while the mountains in Oregon will have a heavy storm skiing day in addition to some heavy snow tonight in the North. Expect 12-20” overnight tonight for Baker, Crystal, and Snoqualmie, with 8–12 at Steven’s. Expect 6-12” of additional snow from tomorrow morning onward for Baker and Crystal, with 4-10” more for Steven’s and Snowqualmie.
Tuesday AM totals for northern Oregon will be impressive, with 12-18” for Timberline and Hood, and lesser amounts of 5-10” for Bachelor and Hoodoo. Very heavy snow will continue during the day with an additional 8-16” for most Oregon resorts. WOW.
California
Don’t let these 2-3 foot totals in the Northwest distract you, the Sierra is going to get slammed too. Same storm, same moisture, same cold = huge totals. Snow levels will be well below normal in California as well, dropping below 1k feet for the northern Sierra and around 2k for the Central Sierra. Perhaps even lower than that.
For the Sierra, snow will start falling Wednesday night into Thursday. The timing is such that there probably won’t be a ton of snow by AM Thursday, but that will change quickly, as 2-3”+/hr snowfall rates are possible Thursday afternoon. This nuclear snowfall will likely last through much of the evening before becoming lighter after midnight around Tahoe, with some heavier snow still falling to the South. By Friday morning, the storm should be wrapping up with some classic sunny Sierra skies and fresh powder.
Winds will likely be an issue during the day on Thursday, impacting lifts and snow quality. However after the passage of the cold front Thursday evening the winds will decrease rapidly, with continued heavy snowfall. Friday is the obvious choice for chasing powder in the Sierra with this storm.
After 10-18” of heavy and wind blow snow during the day on Thursday around Tahoe, expect an additional 4-8” overnight for Friday morning. Mammoth will see the heaviest snow Thursday night, but with strong winds during that period as well. Storm totals for most Sierra resorts should end up in the 1.5-2.5 foot range. Yippy.
Idaho/Wyoming
This storm will move inland and absolutely unload on Idaho and Wyoming as well. With a generally southerly wind, Sun Valley will get nailed too. Pretty much all of Idaho will see heavy snowfall, with the central and southern regions seeing the most. Western Wyoming and the Tetons will add big numbers to the already great week they’re having.
The flakes will start flying in Northern and West central Idaho tonight, with enough heavy snow in the panhandle for a solid powder day at Schweitzer and Selkirk. 5-10” tonight and another 4-8” tomorrow will result in a really good day. Winds will be strong but not devastating.
Central Idaho will see the brunt of its snowfall during the day on Wednesday. Perhaps not enough overnight for deep turns early, but by the end of the day things will be filled in nicely. Another he’s y burst of snow Wednesday night will make Thursday the best day of the two. Brundage will be the big winner in this region. Expect 6-10” during the day on Wednesday, 8-12” Wednesday night into Thursday, 5-10” on Thursday, and then another 4-8” Thursday night. Snorkels?
Sun Valley will also have a long duration snowfall event, albeit a bit less intense than Brundage. Wednesday afternoon through Friday morning will feature consistent snowfall, with 4-8” every 12 hours, with the heaviest falling from Thursday to Friday morning. Persistent low level southerly and southeasterly flow will help keep the faucet on for Sun Valley. Best choice for Sun Valley will be Friday with terrain openings hopefully.
We just had a great day at Grand Targhee on Monday, with 10” of new snow. Well there’s a lot more headed to the Tetons this week, so we hope you’re not sick of powder. Before that, check out this clip from our day at Targhee on Monday.
Some light snow Tuesday night before things pick up on Wednesday, with moderate snow. The intensity will decrease Wednesday evening through Thursday morning, before increasing again Thursday afternoon. Moderate to heavy snow from then until Friday afternoon, resulting in the best pow day on Friday. The heaviest 12 hour period should be Thursday PM to Friday AM, with 6-12” during that time. Expect 3-7” during the rest of the 12 hour periods starting Wednesday. Storm totals of 20-30” expected across Jackson Hole and Grand Targhee, with the latter falling in the higher end of the range.
Montana
From Wednesday morning through Friday afternoon, snow will be falling in Montana too. Northwest Montana will be the focus form Wednesday through Thursday night, with 6-12” of snow during this period. It won’t be especially heavy during tis period, but light to moderate snow will be falling at Whitefish and Montana Snowbowl and adding up.
In Southwest Montana, light snow will arrive midday Wednesday and continue through Thursday, before becoming heavier. From Thursday night through midday Friday the snow will be moderate to heavy at places like Big Sky. Storm total should be int he 8-14” range there, with 3-7” at Bridger and Red Lodge.
Utah/Colorado
Finally, mercifully, we get to Utah and Colorado. We will keep this short and sweet. From Thursday night through Friday in Utah, and Friday through Saturday in Colorado, moderate to heavy snow will be falling. This is looking like another significant event for Northern Utah, with 12-20” possible, and a bit less, 8-16” possible. Some strong winds during the pre frontal SW flow regime followed by NW flow, which is good for Utah and the Northern mountains in Colorado. We will have some additional details on storm totals in Utah and Colorado in a future post.
Extended Forecast
As the first storm is still bringing snow to Utah and Colorado, the next snowy system will be starting to impact Washington. Right now, it looks like this storm has the potential to drop a few additional feet of snow in the Sierra, and 12-18” in Northern Oregon, Utah and Colorado. Additional details to follow with this storm too.
Thanks for reading. Also, final day to buy an Ikon Pass is December, 8.
