Avalanche forecast

East Slopes Central

Northwest Avalanche Center
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Avalanche danger

Sun
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Highlights

The first big warming event of the year, combined with recent snow and a weak snowpack, means you need to carefully assess the snowpack and make conservative terrain choices. To reduce the risk of triggering wet avalanches, time your travel to be off of slopes before they become wet and weak. Use extra caution and beware of snow coming down from overhead slopes.

Avalanche problems

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–3

    Wet snow and rollerballs are signs that you could soon see wet avalanches. You can move to more shaded or lower-angle slopes to avoid triggering avalanches. Time your travel to be off of slopes before they become wet and weak.

    East aspects will be first to warm and west aspects may see the most melt water in the afternoon. Temperatures will be warm enough for wet avalanches, even on northerly aspects. Avalanches could vary in size and consequence; Loose wet avalanches may be small in the morning and they could gouge deeply, becoming large and dangerous as slopes continue to warm.  Wet slab avalanches could occur in the recent snow in the top foot of the snowpack, and they could break widely across large terrain features on weak layers 2-3 feet below the surface. Large avalanches will be most likely midday through late afternoon.

    In the past two weeks, there have been six close calls and one fatality involving avalanches on a layer of weak-faceted snow over a stout crust buried in early February, 2-3 feet below the surface.  Meltwater will drain into the snowpack, making it easier to trigger wet slab avalanches on this buried weak layer. You may be able to trigger them low on a slope or even from below. You're most likely to encounter large wet slab avalanches at mid and upper elevations.

    (1/29/2024)

    An example of a very large wet slab avalanche (d3) from late January.Mission Ridge Ski Area WS-ASu-D3-R4-O/G

Avalanche Discussion

The Cascades are in a stretch of very warm, sunny weather. This is the year's first big, spring-like warming event, with high temperatures in the 50’s and freezing levels over 10,000’. These conditions bring a high level of uncertainty about the extent of avalanches that we'll see, especially with the weak snowpack structure. Smaller wet avalanches, cornice falls, or snow shedding from cliffs can trigger very large avalanches. Consider that this is the time when an ‘improbable’ or unlikely avalanches could occur.

The pattern of persistent slab and now (wet slab) avalanches can be challenging for backcountry decision-making. It takes conservative terrain management and diligent patience. Stepping into steep terrain at mid and upper elevations is simply just a game of chance; you may get away with it, or you could trigger a very large avalanche that is likely to injure or kill you. The structure is especially apparent in the eastern Cascades, where the snowpack is generally more shallow than at the crest. If you're venturing into these eastern zones, be prepared to take a step back in your typical terrain selection and understanding of the snowpack.

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