Avalanche forecast

Northwest Mountains

Crested Butte Avalanche Center
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Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

There is a lingering threat of triggering a slab avalanche on isolated terrain features at upper elevations.  You could release a thin, wind-drifted slab on leeward terrain features that formed in the past few days from a few inches of new snow and wind.  An unlikely chance remains for avalanches to break on old, weak layers deeper in the snowpack on unusually shallow or rocky terrain that faces a northerly aspect at upper elevations.  Steer around features where you encounter recent drifting and avoid northerly slopes that appear abnormally shallow to reduce your chances of triggering an avalanche.

Avalanche problems

  • Wind Slabs

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

    Since Friday, a few inches of snow with gusty southwest to west winds formed isolated slabs on leeward terrain features at upper elevations.  Expect the size to remain on the small end of the spectrum yet sensitive to a person's weight.  Look for evidence of recent slab formation below ridge tops, cornices, or cross-loaded gullies.  In many cases, the fresh drifts may be small enough to steer around them in the terrain.  

    A shallow Wind Slab from Sunday on Mount Baldy.

    (3/30/2025) Photo: Crested Butte Avalanche Center

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    2–2.5

    The distribution of the current persistent slab avalanche problem has narrowed after last week's heat wave. Weak layers in the upper snowpack have become less concerning as they often saw melt water drain through them. Now, the focus has turned back to old facet layers in the bottom half of the snowpack. Don't expect to see any feedback or obvious red flags from this avalanche problem. The problem will remain quiet until it receives a heavy load from a cornice fall, or a light load that finds just the right trigger point where the slab thins above those facets or on slopes with an unusually shallow snowpack from wind or previous avalanche activity. Persistent slab instabilities are even more isolated below treeline, but you should still stay alert on very steep or unusually shallow slopes.   

    A large persistent slab on Gothic triggered by a shallower wet avalanche on 3/25.

Avalanche Discussion

Cooler weather and cloud cover shift attention away from the exiting wet avalanche problems and bring attention back to dry slab avalanche issues lingering across the landscape. Recent snowfall since Friday (possibly up to 8 inches at the highest elevations) has been blown around by recent gusty winds and deposited on leeward terrain features.  This example of a skier-triggered Wind Slab on Mount Baldy from Sunday illustrates the leeward terrain where you could encounter a shallow, sensitive drift.  This avalanche problem is often small, but don't let it catch you off guard.  Weak layers deeper in the snowpack have been relatively quiet recently but continue to threaten backcountry travelers with a large avalanche, particularly on slopes with a shallower snowpack.  A shallow snowpack could be from less seasonal snow, as you might encounter in the Southeast Mountains forecast zone, or from previous avalanche activity or wind-eroded rocky terrain.  This avalanche on Mount Axtell last week is a good example of the type of terrain where you could impact deeper weak layers as it was shallower than most terrain due to previous avalanche activity (this same slope produced a large avalanche in January and reformed a slab since the middle of February).  Identifying slopes with previous avalanche activity may be challenging as they may not present with visual clues.  The distribution of terrain has recently reduced due to the warm weather, so the most problematic slopes now face northwest through north through northeast.

Wet avalanche issues were removed from the problem list. Still, there is an outside chance you will encounter a wet, punchy snowpack at low elevations during the warmest part of the day despite the increasing cloud cover.  Consider choosing lower-angled terrain if you sink deeply into the snowpack or break through surface crusts at low elevations.

A potent wind storm accompanied by strong winds arrives this evening. Expect the avalanche danger to increase on Tuesday as snow accumulates and drifts.  If the high end of forecasted snow materializes, dangerous avalanche conditions may form on leeward terrain features.

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