Avalanche forecast

Rattlesnake

West Central Montana Avalanche Center
View on map

Avalanche danger

Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
Open full map
Out of date — this forecast expired 7 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

Triggering a wind slab avalanche is possible anywhere the new snow has been blown into drifts. Wet avalanches will become possible on solar slopes if the sun comes out. Watch for signs of instability such as recent avalanches, shooting cracks, and wet snow deeper than six inches. If you see these, stick to slopes less than 30 degrees.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    If the sun comes out today, human-triggered wet avalanches will be possible on solar slopes. With warming temperatures and low-density surface snow, it will take very little solar input for new snow to become wet.

    If you find yourself sinking into wet surface snow or see roller balls, stay off of steep southerly slopes and away from their immediate run outs. Even small wet loose avalanches can have serious consequences.

    Pay attention to the weather and snow as you move through the mountains today. Winds and clouds may temper the sun's influence, but high temperatures will exacerbate it. Even though it's only January, wet snow should be on your mind.

  • Wind Slabs

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

    In the past five days, the Rattlesnake has received 18 inches of snow (1.9 inches of water) with moderate westerly winds. This is the ideal recipe for building wind slabs on easterly slopes. Skiers triggered wind slab avalanches in both the Bitterroot and Rattlesnake yesterday. Crowns were up to a foot deep in spots. Clear weather allowed us to see many natural avalanches that had happened earlier in the week. Click here to see the observations page for details.

    Moderate winds at ridge top will have formed new wind slabs overnight and will continue building them today. Additionally, triggering deeper wind slabs from the past few days is still possible.

    Identify wind slabs by looking for pillow-shaped deposits and wind drifts. They are most likely to form just below ridgelines, below roll-overs, and in cross-loaded gullies. Avoid slopes over 30 degrees where you see signs of wind loading.

    (1/10/2026)

    The crown of a small, skier-triggered wind slab on a north facing ridgetop near Point 6. In this photo you can see multiple wind slab layers.

  • Persistent Slabs

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

    This is a low-likelihood, high-consequence avalanche problem.

    At high elevations we’ve found small facets buried just over a foot deep. These facets formed on the snow surface in late December and early January, before getting buried. We have no reports of avalanches on this layer, but we’ve gotten propagation in snowpack tests.

    On solar aspects the sun likely destroyed the facets before they were buried. So, look for this weak layer on high elevation shady slopes.

    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 layers before committing to a line. Strong over weak snowpack structure or propagating extended column tests indicate you should avoid slopes over 30 degrees.

    Deeper buried crusts are still present in the Rattlesnake. However, with no avalanches on them yet this season, we are not currently worried about them as weak layers.

    (1/7/2026) Photo: Arden Feldman

Avalanche Discussion

Snowfall has come to an end, and we’ve moved into a period of high pressure. However, wind overnight may have built new wind slabs on top of old wind slabs, and a few buried weak layers still have our attention. Plus, warm temperatures today could create wet snow problems.

Low-density snow can warm quickly. Any slopes exposed to above-freezing temperatures and direct sun will become wet quickly. If an inversion develops, warming will be exacerbated at high elevations. Pay attention to changing weather, and don’t let wet snow surprise you.

With limited observations, uncertainty exists regarding the near surface facets buried about a foot deep. They formed during the New Year’s dry spell, and are likely only preserved where the snow remained cold. We haven’t seen avalanches on this layer, however visibility has been limited. Up near Whitefish, a skier triggered an avalanche on what appears to be the same layer. Click here for details.

The weak layer in the Southern Bitterroot is associated with a crust buried on December 26th, with underlying facets. While this crust exists in the rest of our forecast area, we haven’t found facets underneath it anywhere else. The facets below the crust are the reason we remain concerned about this layer in Lost Trail area. We’ve continued to see propagation on this layer where facets exist under the crust.

If you see any avalanches, please let us know about them. If you dig in the snow, please let us know what you find. Tests are helpful but not necessary, even a photo of your snow pit wall is useful. Your information helps us reduce uncertainty, which leads to a higher accuracy forecast.

Regions covered