Avalanche forecast

Northwest Mountains

Crested Butte Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

Avalanche conditions are generally safe.  Warming temperatures and sunshine may create small wet snow avalanches by the afternoon.  Monitor the snow surface on steep, sunny slopes, particularly around rocky areas where you could trigger a small wet loose avalanche.  An outside chance exists for you to trigger a slab avalanche on the north half of the compass on slopes with an abnormally shallow snowpack or in extreme terrain.

Avalanche problems

  • Loose Wet

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

    Sunshine and warming temperatures will increase the threat of shallow wet avalanches in the surface snow.  Watch for rollerballs, pinwheels, or natural sluffs to indicate developing instabilities first on east, then south, then west aspects.  Natural and triggered sluffs are most likely to initiate from very steep or rocky slopes.  Be careful in or above consequential terrain once the snow surface gets wet or sticky.  You can avoid triggering wet loose avalanches by riding on slope angles less than 35 degrees or moving to colder aspects.  

    (3/18/2024)

    Recent wet loose avalanches from Peeler Peak.

    Photo: Zach Guy

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    2–3

    In the Northwest Mountains, high-consequence slabs breaking on older weak layers have become isolated and difficult to trigger. Any lingering persistent slabs are most likely triggered from an unusually shallow or previously wind-eroded slope where the total snowpack height is below average.  Large cornice falls could act as triggers as well. Persistent slab avalanches can be remotely triggered from low-angle terrain and break deeper and wider than you might expect.  The most problematic structures are on shallower slopes on the north half of the compass.  Mid to low-elevation, southerly aspects have the most trustworthy snowpack.  Slope angles consistently less than 30 degrees are a reliable way to avoid the problem when in doubt.  

    The crown of a very large persistent slab remotely triggered by snowmobiles on March 8.  This slope is west facing and eroded by seasonal winds, making for a shallower and more problematic snowpack than other slopes. 

Avalanche Discussion

Wet snow concerns exist in both forecast zones due to seasonally warm temperatures and sunshine.  Wet avalanche problems are expected to remain small with this observation from yesterday illustrating the current character.  A few places could produce natural sluffs today; very rocky areas that are warmer than open slopes and the lowest elevation sunny slopes where warmer temperatures more effectively wet the upper snowpack.  Small human-triggered sluffs may occur on other slopes on the south half of the compass with upper-elevation terrain that holds some dry, surface snow from earlier in the week potentially gathering more volume.

The Persistent Slab problem is a more concerning and unpredictable issue.  Recent avalanche activity and observations suggest that shallower snowpacks on the north half of the compass represent the most likely place for you to trigger a dangerous slab avalanche.  You are more likely to encounter a shallow snowpack in the Southeast Mountains, but a thin snowpack can still be found in isolated places in the Northwest Mountains.  A recent natural avalanche in Terminator Chutes on Saturday and a triggered avalanche resulting in a close call near Snowmass on Monday highlight the issue.  Both of these avalanches occurred in terrain with shallower snowpack due to less seasonal snowfall and/or previous wind erosion.  You can reduce your risk of triggering a slab avalanche by traveling where the snowpack is consistently deeper than 200cm (~ 6 feet).

Thanks to everyone who helped out or participated in the Al Johnson on Sunday. We appreciate the community support and love to see all the great costumes!

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