Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Out of date — this forecast expired 2 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Soft tempting snow and a potentially weak snowpack make a terrible combination. Recent large avalanches failing on weak old snow highlight the danger. Don’t try and outsmart this issue. Stick to lower angled or treed terrain.

Avalanche problems

  • Storm Slabs

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

    Cold temperatures left several feet of light fluffy snow all across the zone. A strong cooling trend means most of this snow is right-side-up. However, temperature fluctuations early in the storm and periods of heavy snowfall left a few inter-storm layers that could produce avalanches.

    You’re most likely to trigger a storm slab in wind affected snow, on very steep slopes, or near convex rollovers. Most of these slides should be small and soft. However, they could trigger deeper avalanches.

    With such light dry and fluffy snow, even if you don’t trigger a slab, you could cause dry loose sluffs. Some of these slides could run far and fast with so much new snow.

    (2/1/2025)

    An intentionally triggered small storm slab. 3-12" deep, and 20 feet wide. SS-ASc-D1-R2-S, NE, 6200ft

    Photo: Dallas Glass

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

    The evidence continues to mount supporting a persistent slab problem. Avalanches at White Pass, Mt Adams, and possibly Mt Rainier all appear to have failed in old weak snow. This combined with numerous snowpack tests and a well documented weak layer all point towards unstable snow. The only real theme seems to be the layers are most prevalent on shaded aspects.

    Given the depth (1.5-2.5ft) and variability of the weak snow, this problem will be very tricky to manage. It’s nearly impossible to say with any certainty if any one slope may slide. Tracks on a slope don’t mean it’s safe.

    Keep it dialed back and stay off of steep open slopes. Many of the avalanches reported on these older snow layers propagate widely releasing the entire width of the feature.

Avalanche Discussion

This storm has been good to the West South zone! Snow totals reached 18-30 inches and counting! With very cold temperatures expect several more inches of low density snow to add to the fun.

This new snow is great and super exciting! Don’t let it lure you in. Sure you find slopes that didn’t slide and snowpack tests that didn’t fail, but there is plenty of evidence pointing towards a persistent weak layer in the snowpack. Stay focused on the signs of instability.

Weak snow from the January Drought and facets around the 1/10 crust could both be the culprit. While these weak grains have been observed across the zone, we haven’t heard of any avalanches or significant snowpack tests in the Crystal backcountry. That could change as the slab grows or stiffens.

On Sunday an NWAC forecaster at Paradise spotted a deep recent natural side (ENE, 5900ft). A deep slide on the January Drought Layer (JDL) was also reported on Mt Adams (E, 6000ft). These add to the slide from White Pass on Saturday (NE 6200ft). Hand pits and small slopes aren’t showing this layer very well and can leave you with a false sense of security. The most consistent test seems to be a propagation saw test.

With all the new snow, expect deep snow conditions. It’s not uncommon to be waste deep out there.

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