Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
3 · Considerable
Treeline
3 · Considerable
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Out of date — this forecast expired 8 months ago.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

Strong to extreme winds are expected to transport snow onto leeward slopes, creating dangerous avalanche conditions. Slabs may form in atypical locations, such as the other side of the ridge or further downhill than you're used to. Using visual clues, such as actively blowing snow, can help you determine wind-loaded slopes to avoid.

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, see shooting cracks, or encounter firm, hollow-feeling snow, seek out sheltered, lower-angled terrain.

    (12/23/2025)

    An intentionally triggered slab avalanche failing down to the 12/18 crust on a wind-loaded slope at Crystal Mountain.

    Photo: Crystal Mountain Pro Patrol

  • Loose Wet

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

    This problem isn't a slam dunk since the weather forecast is still murky. But temperatures are expected to warm, and precipitation is on the way. That could lead to rain-on-snow, or maybe snow shedding from trees and rocks, resulting in loose avalanches. On the flip side, those stout winds could keep everything in place.

    If they occur, these slides will likely 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.

    (12/18/2025)

    Very small loose avalanches that originated near trees and rocks. Similar activity could occur on Wednesday. 

    Photo: Dallas Glass

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. 

With plenty of snow available for transport, a good sliding surface in the 12/18 melt-freeze crust, and an uptick in recent avalanche observations, it's not a stretch to conclude that dangerous avalanche conditions are likely to develop on Wednesday. The snowpack around the zone remains relatively shallow, which could make slabs easier to trigger. Be especially leery of steep, rocky terrain, particularly if it is wind-loaded. That seems to be where most of the recently observed avalanches have occurred.

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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