Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Wet avalanches will remain a focus on Sunday as warm temperatures and incoming rain impact the snowpack. Once the rain begins, expect the distribution of wet slides to expand to all aspects. The threat of larger, unpredictable slides is expected to increase as more water enters the snowpack.

Avalanche problems

  • Loose Wet

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

    Sunday will be another day where wet loose avalanches are possible, but the details are changing. You'll need to manage both solar-induced and potentially rain-influenced wet slides throughout the day. We've been in a warm period since Thursday without a solid refreeze. Each day, we receive reports that the snow is getting "ripe" in the sunshine and is becoming pushable enough for wet avalanches. Natural slides have occurred and may continue to do so. Expect similar conditions on Sunday morning, at least until the clouds roll in. 

    At that point, round two of wet loose slides could occur as rain starts to fall. There isn't much dry snow out there, but whatever hasn't been beaten down by the sun could quickly destabilize. Slopes that are already wet and sticky could reach a tipping point with an influx of rain. Similarly, sagging cornices or snow clinging to rocks will have a higher likelihood of falling. Peak activity could occur Sunday night, but with long daylight hours and people pushing further into the mountains, it's worth having these larger and more dangerous slides on your radar during the forecast period.

    In either scenario, look for rollerballs, pinwheels, or fan-shaped avalanche debris. If you're sinking into wet and sticky snow deeper than your ankle, you should head for lower-angled terrain, remaining aware of what's above you.

    (4/5/2025)

    Wet avalanches were observed on Mount Adams. These originated near rocky outcrops where the snowpack is weaker.

    Photo: Joe Dellaporta

Avalanche Discussion

Sunday will be a transition day as we move from sunny to rainy weather. The constant is that it will remain warm, with rain expected to reach well into the upper elevation band. The timing of the rain is uncertain; however, it is advisable to make travel plans that allow you to return to your car quickly once it begins. It should start up on the volcanoes sometime in the afternoon hours.

We're not exactly talking about a catastrophic atmospheric river here. Still, roughly an inch of rain is expected near the crest, with more on the volcanoes from Sunday afternoon through Monday night. For the most part, we're focused on the roughly 1 foot of snow over the March AR crust. But that's enough rain to start worrying about larger, deeper wet slides as this storm progresses. Sagging cornices, blocks of snow clinging to rocky ledges, or wet slabs may begin to fail once we get a few hours of rain on our snowpack. We're expecting most of that activity to occur on Sunday night and Monday, which falls outside this forecast period. However, with higher consequences and a different management approach than a standard wet loose problem, you should consider limiting your overhead exposure once the rain begins. 

Despite all the talk of warm and wet weather, we haven't yet transitioned to a springtime snowpack. Below the variable March AR crust, our snowpack contains moist melt forms and is considered warm and weak. Below that, it is still cold and layered. At lower elevations, spring has sprung. Bare ground is becoming increasingly common, especially on southerly aspects. Expect thinning snowpacks, open creeks, and plenty of tree debris. That's not to say there isn't enough snow in some areas for avalanche hazard. If you're sinking into wet snow past your ankle, assume wet slides are possible.

As a reminder, if you're traveling high on a volcano, the NWAC forecast may not be directly applicable. Expect to find a more winter-like snowpack. Be prepared to make your own assessments and be leery of icefall or other shed-style avalanches. 

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