Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Out of date — this forecast expired 2 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Stormy weather is expected overnight and into Sunday. With significant new snow and strong winds, every steep open slope is suspect. Seek out lower-angled or more treed terrain if you venture out into the storm.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Enough new snow should accumulate at middle and upper elevations to pose a real hazard. There are three questions you can ask to help determine how likely you are to trigger an avalanche. 

    1. What did the snow fall on? Dig down with your hand as you travel. The new snow should bond well to the underlying wet snow. Once frozen, this often presents as a crunchy crust. If the new snow sits on a layer of ice (freezing rain), it may slide off very easily. 
    2. Is the snow influenced by the wind? Look for clues like blowing snow, drifts, or firmer slabs. These wind-loaded areas could produce larger and easier-to-trigger slides. 
    3. Are there layers within the new snow? Weak layers can form within the storm from changes in precipitation rate, temperature, or even snow crystal type. Hand pits, uptrack tests, and small slopes can all highlight inter-storm layers that are more likely to slide. 

    Given the dynamic nature of this storm, you could encounter plenty of spatial variability. Make frequent observations that can tip you off to more likely avalanches. In these spots avoid steep, open slopes.

    (2/28/2024)

    Example: You can use uptrack tests like this to check the old/new interface. 

    Photo: Dallas Glass

Avalanche Discussion

This storm is messy. It’s hard to give much in the way of specifics. Limited information from Saturday just makes the uncertainty a bit higher. 

What we know: It rained well above the highest peaks in the area. This likely destroyed any pesky surface hoar or facets sitting on the surface. As temperatures cooled, it should have helped the snow stick to the old surface. Cold air trapped at lower elevations caused freezing rain and ice coated many surfaces. This could make travel very difficult, even with new snow. 

Lower elevation snow packs were thin before this storm and the rain didn’t help. Numerous obstacles and a very rough surface should limit the size of any possible avalanches. The new snow may cause many slopes to look inviting, but just peruse the images of the zone prior to this snowfall. There are lots of obstacles to hit. Give yourself time and travel cautiously at low elevations. 

What we don’t know. Given the rain on snow Saturday, there likely were natural avalanches. We don’t know the size or extent of any cycle. Be on the lookout for piles of frozen debris. Glide avalanche activity won’t stop on a dime. Even though it’s snowing, give areas below crevasse-like cracks a wide berth. It’s unclear how high in the terrain the freezing rain ice layer extends. It could be higher east of the Pass proper. 

A Puget Sound Convergence Zone might bring intense precipitation to the zone on Sunday morning. Natural avalanches could occur during periods of very heavy snowfall.

Regions covered