Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

Expect large natural and human triggered avalanches as strong snow and wind create dangerous conditions. Wet snow avalanches are possible if rain falls at lower elevations. Travel in avalanche terrain is not recommended.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    2–2.5

    Significant wind speeds accompany the strong atmospheric river impacting the zone through Thursday. You will find wind-loaded snow in atypical locations i.e. lower down on slopes and in exposed terrain at lower elevations. Wind slabs can appear as smooth or rounded pillows, but this may not be obvious as new snow quickly obscures wind-loaded areas. Expect to find wind-drifted snow just below ridgelines and in cross-loaded gullies. If you encounter cracking and collapsing in more sheltered areas, you have found storm slab instability. Travel in low angle terrain well away from steep slopes.

    (12/23/2024)

    Cracking in wind drifted snow on Darland Mountain.

    Photo: Payton Schiff

  • Loose Wet

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

    Snow will shift to rain below 3500 feet as precipitation tapers off on Thursday. If enough rain falls, it will rapidly destabilize new snow that previously fell. The typical progression of wet loose avalanches involves rollerballs and pinwheels that lead to point releases. If you start to get rained on, limit your exposure to large paths. Don’t linger in terrain traps where avalanche debris can concentrate and be aware of steep terrain overhead where avalanches can start.

    (12/19/2024)

    Looking up at the debris from a small wet loose avalanche.

    Photo: Payton Schiff

Avalanche Discussion

Wednesday's weather forecast: "With this Christmas and Boxing Day day storm Santa delivers a serious punch. This storm is likely to go down as one of the most significant of the year in terms of snow accumulations and contends as a significant mountain wind event." In summation: new snow + strong wind = avalanches. It is imperative that you stay alert if you venture into the backcountry.

If you still need more convincing, here are a few more considerations. Avalanche danger is always the highest during or immediately after a storm. New wind slab formation can overload older wind slabs or lingering weak layers at upper elevations and produce a bigger and even more consequential avalanche. Rain on snow at lower elevations adds an extra layer of complexity to backcountry travel. The best way to manage the hazard is to practice patience and avoid avalanche terrain while you nurse your eggnog hangover.

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