Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Out of date — this forecast expired 8 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

A major east wind event is forecast for the Snoqualmie Pass zone on Wednesday. Using visual clues, such as looking for actively blowing snow, can help you identify where unstable slabs may exist. They might be on different slopes than you're used to. 

Avalanche problems

  • Wind Slabs

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

    The winds are expected to be cranking on Wednesday! If the forecast holds, east winds will easily transport snow onto leeward slopes, forming wind slabs. With east wind events, we often see atypical loading patterns. Not only will slabs be on a different aspect than you're used to, but they could form further down in the terrain, and slopes may be cross-loaded.

    No matter where they develop, you can use visual clues such as actively blowing snow, textured surfaces, fresh cornices, or large pillow-like drifts to help identify wind-loaded slopes. Take it slow and assess conditions carefully, using small test slopes or uptrack tests to look for instability in the upper snowpack. If you suspect a slope is wind-loaded, seek out sheltered, lower-angled terrain.

    (12/23/2025)

    Upper elevations are filling in nicely and have a higher potential for avalanches. At least one sizable slab was visible during this quick glance at the Chair Peak area.

    Photo: Andy Harrington

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    This problem isn't a slam dunk, given the challenging weather forecast, but hey, this is Snoqualmie Pass. There is confidence that temperatures will rise, and some precipitation is expected. That could lead to rain-on-snow, or maybe just snow shedding from trees and rocks, resulting in loose avalanches. However, those stout winds could keep everything in place. 

    If they're going to happen, these slides should start at a point, such as near rocks or trees, and then fan out as they move downhill. Although they're not expected to be very large, don't let one push you into a terrain trap or into the many exposed natural hazards that still exist in the mountains right now.

    (12/23/2025)

    Loose avalanches caused by snow shedding from trees onto a steep slope. Similar activity may occur as temperatures warm on Wednesday.

    Photo: Andy Harrington

Avalanche Discussion

After multiple days of snow showers that helped build our early-season snowpack, we're anticipating our next major weather event on Wednesday. This time, it is expected to take the form of a significant windstorm. Although there is a lot of uncertainty in the weather forecast, we feel confident that it will be windy, with precipitation and rising temperatures. 

Observations from mid to upper elevations remain limited at the Pass, but one thing is for sure: there is plenty of snow available for transport. NWAC forecasters found ~70cm of recent storm snow at 4500' on Tuesday, and The Summit at Snoqualmie Pro Patrol reported wind transport and a few small avalanches near the top of Alpental. We are expecting a significant uptick in danger and avalanche potential on Wednesday. 

As temperatures rise, watch how the snow surface is changing. Apart from loose slides, the recent storm snow could "slab up" and become upside-down. Additionally, it wasn't that long ago that we had major atmospheric river events that totally saturated our soil, weakening the roots of many trees. With such a significant wind storm on the horizon, it may not be the best time to hang out in the forest. Trees may be more prone to falling than usual, and snow shedding as "tree bombs" could fall without warning. Add it to the list of early-season hazards you'll need to manage, along with open creeks, downed trees, and exposed rocks.

State and local resources are working diligently to reduce the impacts of destructive storms that occurred earlier this month. We can help by respecting affected communities, complying with road closures, and adhering to ski area uphill travel policies.

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