Avalanche forecast

Stevens Pass

Northwest Avalanche Center
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Avalanche danger

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

Forecast models vary, but no matter what, we'll be getting a little snow overnight and a bit more during the day, which is enough to increase our avalanche hazard. Identify wind-drifted features and avoid traveling on steep, wind-loaded slopes with deposits deeper than a few inches, which is where you're most likely to trigger an avalanche. 

Avalanche problems

  • Wind Slabs

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

    You're most likely to trigger and get caught in a wind slab avalanche on Wednesday. Search for thicker, heavier deposits and textured or pillowlike surfaces. They tend to collect on one side of ridges and rolls, around rocky outcroppings, and in gullies. You can use small test slopes or simple hand tests to determine how snow is bonding to the underlying layer. In areas where you find drifts, avoid slopes greater than 35°.

    We expect most avalanches to fail about as deep as the new snow layer, so aside from the odd deeper wind slab, they will probably be drifts less than a foot deep. At higher elevations, there's a small chance avalanches could be deeper, taking out snow we received over the weekend as well, which means there's a slight chance of avalanches closer to 2 feet deep. 

    (12/15/2024)

    Example photo: Small reactive wind slab formation, similar to what you might see on Wednesday. 

    Photo: Ryan Minton

Avalanche Discussion

This storm is accompanied by an easterly effect, so we may get stronger wind and more snow than forecast models suggest. If this is the case, expect more avalanche activity, and consider avoiding all steep slopes with greater than about 6 inches of snow-not just the wind-loaded ones. Wet snow and accompanying small wet avalanches could exist up to about pass level. If you notice wet avalanches or rollerballing, avoid similar steep slopes and terrain beneath them. 

Over the weekend, we received a little less than a foot of snow, with natural and human-triggered slab and dry loose avalanches reported. By Monday, there was much less activity. An observer on Jim Hill on Tuesday found wet snow that transitioned to dry snow in the mid-elevation band, and heard a natural avalanche at higher elevations, although it's hard to say where or what type of avalanche it was. Other debris piles from wet and dry, slab and wet loose avalanches, have been seen in the zone in the last 2 days. We expect at least a subtle crust to form Tuesday night before the storm. New snow could slide easily on the firmer underlying layer, but we also have a lot of uncertainty and there's a chance the new layer will bond well. Plenty of small semi-hard debris piles exist as well.

The recent storm tested the persistent slab, which is now buried 2-3 feet beneath the surface. Pit tests and explosives used at the ski area in the last few days have found that this layer is generally unreactive. An incoming warm wet storm this weekend will provide one last test to tickle out any weaknesses in the near term.

If you get out in the backcountry, please share what you see by submitting an observation HERE or on the Avy App. 

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