Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Wed
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

The southern half of the zone should remain stormy with dangerous avalanche conditions. New snow avalanches will continue to be the issue throughout the zone, but the size and reactivity may vary based on your location. Ease into the terrain by starting on small slopes before moving to bigger or more consequential terrain.

Avalanche problems

  • Storm Slabs

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

    Throughout much of the zone, the reactivity of the storm snow should be on a downtrend on Tuesday. Instead of worrying about slabs and loose avalanches on every slope, you may want to start to hone in on wind-loaded terrain, convex, or unsupported slopes. The exception will be in the southern half of the zone, where stormy weather should continue, resulting in higher avalanche potential. Regardless of your location, slabs should be larger and possibly more reactive as you ascend in elevation or in wind-loaded terrain. Most avalanches should be confined to this weekend's storm snow, but we can't rule out a few slabs breaking deeper, possibly down to the AR crust. Use quick hand pits, uptrack tests, or small test slopes to gain insight into the reactivity of the upper snowpack. To look at the potential for deeper avalanches, you should dig down with your shovel and perform more formalized tests.

    (3/16/2025)

    This slab avalanche was triggered by skiers who were skinning uphill near Crystal Mountain. 

  • Loose Wet

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

    We expect enough sunshine on Tuesday that wet loose gets the nod as an official problem. However, there will be competing weather factors like clouds and breezy winds. You'll have to see how the weather is panning out wherever you are recreating to see if this problem manifests. Wet avalanches could occur if the sun is winning the battle and the snow surface is getting moist and sticky. Rollerballs, pinwheels, or new fan-shaped avalanche debris are all good indications that you need to head for shadier aspects, keeping aware of slopes above you. 

Avalanche Discussion

Recent storms left a couple of feet of new snow, including several interfaces and even a few thin crusts on sunny aspects. These layers should heal quickly, but don’t jump into big terrain too fast. Numerous avalanches were reported from 3/11-3/15, including at least two partial burials in the zone. With continued snowfall, particularly in the southern half of the zone, expected on Tuesday, we will add another interface to the puzzle. The atmospheric river (AR) crust is buried roughly 3-4 ft below the surface in many places. On Friday, an NWAC forecaster near Crystal Mt found facets within the upper AR crust. We don’t know how common these weak grains are, but they are something to watch for if you’re digging.

On Mt St Helens and Mt Adams, Saturday’s storm hit a little harder, and they're getting a bigger shot on Tuesday. In these areas, closer to a foot and a half of new snow likely fell with strong winds. Our friends at the Cascade Volcano Observatory shared seismic data indicating that numerous large to very large natural avalanches occurred on Mount St. Helens and Mount Rainier during the storm. On Tuesday, you could encounter dangerous conditions on any steep open slope on the volcanoes.

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