Avalanche forecast

Bitterroot

West Central Montana Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 6 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

Large human triggered avalanches are possible at middle and upper elevations, especially on shaded or wind loaded slopes. Dig in the snow and look out for weak layers buried 1-2+ feet deep by a stiffer slab. If you experience whumfing, collapsing, shooting cracks, or see fresh avalanches, stick to low angle slopes without steep terrain overhead. 

Avalanche problems

  • Persistent Slabs

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

    Recent snowfall built a 1-2+ foot thick slab above persistent weak layers like surface hoar and near surface facets. Triggering a large avalanche on these layers is possible. Skiers triggered multiple slab avalanches on Tuesday. Upper elevation slopes that are shaded or wind loaded with a stiffer slab are the most concerning, but avalanches are also possible lower down in wind protected areas. 

    Identify buried surface hoar by digging into the snowpack and looking for a thin grey line 1-2+ feet below the snow surface. Buried near surface facets will present as weak sugary snow crystals. The warm weather and sun last week likely helped destroy the buried surface hoar on solar slopes. However, these slopes could still have buried crust facet layers. You may not see any red flags before triggering an avalanche on these layers. If you find poor snowpack structure in your snowpit with a slab above a weak layer, or experience collapsing or whumfing, stay off slopes over 30 degrees. Persistent slabs could also be triggered remotely, from low angle slopes above, below, or to the side of steeper slopes. 

    A common trap with surface hoar is to dig high in start zones and not find it, then descend partway down the slope and trigger an avalanche on buried surface hoar. It can get destroyed high on slopes but preserved lower on the slope, creating tricky conditions for slope level snowpack assessment. If you dig a pit high on the slope and do not find buried surface hoar, do not trust that there is no buried surface hoar lower on the slope. Also, buried surface hoar can produce avalanches that fail on especially low slope angles, even below 30 degrees in extreme examples.

    (2/10/2026)

    Skier triggered slab avalanches in the Rattlesnake zone

Avalanche Discussion

It will be another nice day in the backcountry with increasing clouds, light winds, and warm temperatures. The forecast area received 6-18” of new snow on Monday - a welcome sight! However, don't let the nice weather and new snow lull you into complacency. With a fresh slab above a variety of weak layers, conditions have become more dangerous in the backcountry. 

There is a high degree of spatial variability and uncertainty surrounding the buried weak layers. We know that surface hoar, near surface facets, and crust facet layers were all buried by the recent snowfall. Buried surface hoar is a particularly tricky persistent weak layer. It can be very difficult to predict which slopes it exists on. Just because it’s not on one slope doesn't mean it isn’t on a similar slope nearby. Additionally, you might not find it at the top of a slope, but it could still exist partway down the slope. The near surface facets and crust facet layers add even more variability to the equation. So, even if you don’t find buried surface hoar, other weak layers could prove hazardous. The main takeaway here is that conditions are complicated, and careful slope assessment is required in the backcountry right now. If you want to avoid the problems entirely, you can stick to low angle slopes without steep terrain overhead. 

Unfortunately, these weak layers take time to heal, and we will likely be dealing with them for a while. With an active and snowy weather pattern in the forecast starting this weekend into next week, we can expect the slab to grow and increase the load on the weak layers. Conditions could change rapidly, with avalanches becoming larger and more sensitive. The fresh snow could also bury a new layer of surface hoar that grew this week. Stay alert for changing conditions. 

Today will be cloudier than yesterday, but with some sun still in the forecast, you could find small wet loose avalanches on steep, sunny slopes. Surface melt-freeze crusts on south aspects will have to break down for wet loose avalanches to occur. If you find yourself in mushy, wet snow or start seeing rollerballs, consider avoiding avalanche terrain. 

Glide cracks are opening up throughout all zones. Glide cracks are very unpredictable and can fail minutes after the crack opens or months after. Avoid spending time under open glide cracks. Cornices have the potential to break off naturally during periods of warming. Minimize the time you spend underneath overhung cornice on warm days. 

Avalanche education is a lifelong journey built on developing sound judgment, gaining experience, and applying repeatable decision-making systems in the backcountry. Our American Avalanche Association (A3) recognized Level 1, Rescue, and Level 2 courses are offered throughout the winter and help you travel smarter in avalanche terrain. Explore current courses and registration on the Education page. 

Please continue to submit observations, and ski and ride safe!

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