Avalanche forecast

Stevens Pass

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Highlights

Wet avalanche concerns continue with the ongoing rain. You can trigger small and large wet avalanches on steep slopes, and natural avalanches running from steep slopes are possible. Avoid all steep slopes, and if you see very large, gouging slides or many large avalanches running naturally, avalanche danger could be higher, so steer clear of all avalanche terrain, including where avalanches run and stop. 

Avalanche problems

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1.5–2.5

    A round of wet loose avalanches initiated Monday morning when the deep layer of dry snow first got wet. Warm temperatures and over an inch of water on the snowpack as of Tuesday evening have kept small amounts of continued wet loose avalanche activity on the table, which we can expect to still see on Wednesday.

    Around an inch of rain will fall Tuesday night, and a little over half an inch will continue on Wednesday. This will also be day 3 of warm, wet weather, and there might be a slight uptick in activity, with the possibility of larger, less predictable wet-slab avalanches releasing naturally. At Considerable danger, natural avalanches are still possible. 

    Avoid travel on all steep slopes, especially areas near rocks and large, unsupported features that roll over and get steeper. If you see many fresh, natural avalanches gouging deep into the snowpack, or large wet slabs releasing, then very dangerous conditions exist. It's time to take a full step back and avoid all avalanche terrain, including lower-angle slopes beneath steep slopes. Wet avalanches, even if small, can be forceful enough to injure you or push you into hazards, even if they're not big enough to bury you. 

    Example photo: Wet slab avalanche like one that may run, along with more wet loose avalanches on Tuesday. If you see these begin running naturally, then danger is higher. Avoid all avalanche terrain. 

Avalanche Discussion

With a larger overnight rain burst than we've seen so far during the wetting period, there's a lot of uncertainty about when we'll see an uptick in avalanche activity. Warm, wet weather will continue through Friday, and water will percolate further into the snowpack. There could be another period of peak instability and a round of wet slab avalanches resulting in large and very large avalanches. This may be Wednesday, which will result in greater danger than forecasted, or possibly later in the week. 

There are two crusts in the top 3-4 feet of snow. One is midway through the storm layer, from a warmup on the 12th, and the one beneath that, the 3/8 crust, is at the bottom of the storm layers. Plus a thick layer of weak, wet grains about 4-5 feet below the surface. These could all be sources of deeper wet avalanches in the coming days. From the 11th to the 14th, professionals and observers reported an impressive cycle of large to very large natural and triggered slab avalanches. By the 15th, avalanches were becoming more difficult to trigger, and the storm snow was bonding well, as found by an NWAC forecaster near Lanham Lake.

At upper elevations, we have limited information. Older weak layers from February would be difficult to trigger, but they may not have been wetted as much as those at lower elevations. Be ready to assess the upper elevation snowpack if you travel there. Consider the consequences of falling in wet, deep snow. At mid and lower elevations, holes around boulders and creeks may be barely covered and could lead to a dangerous fall. Make sure to keep close tabs on your partners in case you need to rescue them. 

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