Avalanche forecast

Bitterroot

West Central Montana Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Out of date — this forecast expired 8 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

Fresh wind slabs will grow at upper elevations today. Large human triggered avalanches are possible. Stick to low angle slopes if you see red flags like recent avalanches, shooting cracks, or collapsing. Although unlikely, you could also trigger deeper avalanches that fail on buried weak layers around crusts. 

Isolated areas of the Bitterroot that receive the higher end of snow forecasts today could reach CONSIDERABLE avalanche danger. If you experience heavy snowfall, expect larger wind slabs and storm slab avalanches in wind protected areas. 

Avalanche problems

  • Wind Slabs

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

    Southwest winds will drift 3 to 7 inches of new snow into fresh wind slabs at upper elevations today. These are growing on top of wind slabs that formed over the last 48 hours. Large human triggered avalanches are possible anywhere the wind has drifted the new and recent snow into slabs 6 inches thick or more. 

    Wind slabs often form just below ridgelines, below slope convexities, and in cross-loaded gullies. Identify wind slabs by looking for pillow-shaped deposits and wind drifts. Wind slabs are most likely today on northeast, east, and southeast aspects. Avoid slopes over 30 degrees if you see signs of instability like recent avalanches, cracking, or collapsing. 

    If you find yourself in an isolated area that receives higher than forecast snow totals today, expect wind slabs to be larger and more sensitive. Additionally, storm slab avalanches could develop in wind protected areas. 

    (1/2/2026)

    Small fresh skier triggered wind slab on an upper elevation east aspect

    Photo: Arden Feldman

  • Persistent Slabs

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

    Although unlikely, you could still trigger a large persistent slab avalanche that breaks 2 to 4 feet deep. This is a classic low-likelihood high-consequence avalanche problem. Our main concern is a weak layer of sugary facets surrounding a crust that formed in mid-December. We have not seen recent avalanches on this layer, but it has been reactive in snowpack tests. If you’re unlucky, you could find the right trigger spot. 

    You are unlikely to see obvious signs of instability, like cracking or collapsing, before triggering a persistent slab avalanche. Dig down and look for weak snow surrounding crusts. If you find strong snow over weak snow, stay off slopes over 30 degrees. 

    The highest elevation north-facing slopes have additional weak snow near the ground. This snow is gaining strength, but could be triggered in isolated areas by a very large load.

    (12/31/2025)

    Snowpit on a northeast aspect at 7650 ft in the Bitterroot

    Photo: Arden Feldman

Avalanche Discussion

There is a large range of forecast snow totals for today, especially in the Bitterroot. Most areas are only expected to receive 2 to 5 inches of new snow. However, some isolated areas of the Bitterroot could receive 6 to 10 inches, which would likely bump the avalanche danger up to Considerable. This appears most likely to occur in upper elevations of the central and northern Bitterroot. If you find yourself in one of these areas receiving heavier than forecast snow totals, stay alert for more dangerous avalanche conditions. Wind slabs will grow larger and more sensitive, and storm slab avalanches will become possible in wind protected areas. Keep track of snow totals today and be prepared to take a step back depending on what you find. Avalanches in the new and wind drifted snow could be extra sensitive because they lie on weak snow surfaces that formed earlier this week. 

Rain is forecast for lower elevations (below 5500 ft) today, and they likely haven't been frozen for a few days. Most lower elevations don’t have enough snow for a significant avalanche, but if you find yourself sinking into wet or unsupportable snow, or seeing roller balls start to entrain mass, it’s time to get out of avalanche terrain. 

Snow totals will continue to pile up over the next several days. Stay alert for changing conditions and increasing avalanche hazard. 

Keep in mind that the persistent slab problem still lingers. Each new storm increases the weight of snow over existing weak layers and changes the structure of the overlying slab. Eventually, the increased load can lead to a period of persistent avalanche activity. Sometimes a series of small incremental loads can tip the balance. 

Let us know what you see by submitting an observation. We appreciate all observations, no matter how small, as our forecast area is large, and it helps us understand conditions across all zones. 

Ski and ride safe!

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