Avalanche forecast

Gunnison

Crested Butte Avalanche Center
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Avalanche danger

Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Out of date — this forecast expired 2 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

The mountains around Crested Butte endured a significant avalanche cycle on Tuesday and Wednesday. Thanks to an atmospheric river event that deposited 2 to 4 feet of snow.  Conservative terrain selection or careful snowpack evaluations are required to manage the potentially dangerous avalanche conditions. The most likely areas to trigger a large avalanche are on aspects that face west to north to east, while southerly facing slopes offer safer avalanche conditions. 

Avalanche problems

  • Persistent Slabs

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

    A significant avalanche cycle occurred on Tuesday and Wednesday following a major winter storm. Many of these avalanches were breaking 2 to 4 feet deep and releasing on weak faceted snow that formed earlier this winter. The upper snowpack is gaining strength, and this will decrease the obvious signs of instability in some areas as this avalanche problem slowly becomes more difficult to trigger. The most problematic aspects face west, north, east, and some southeast-facing slopes. The current travel advice is to avoid this avalanche problem. One way to avoid this problem is by traveling on low-angled slopes less than about 30 degrees that are not connected to steeper slopes above.

  • Storm Slabs

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

    Instability within the 2 to 4 feet of storm snow are settling out and gaining strength.  If you are traveling in big alpine terrain, that isn't highlighted by the persistent slab problem,  you will need to confirm that the snowpack in your local area is following this positive trend. You can reduce your chance of triggering an old storm slab by avoiding previously wind-loaded terrain and by keeping your slope angles under 35 degrees. 

    A smaller storm slab avalanche is visible on the south-facing slope in the foreground, while a larger persistent slab avalanche is in the background. 

Avalanche Discussion

A clear sky has allowed us to begin documenting the significant avalanche activity during this week's major winter storm. This link will pull up a graph of the avalanche activity that is documented so far. Currently, we have 157 avalanches in this data set. The most widespread avalanche activity occurred on west, north, and east aspects. This should be no surprise, as these aspects held well-documented weak and faceted snow that is now buried under this week's storm snow. There were also several widely propagating avalanches on SE-facing slopes, primarily above 11, 700ft, and we have added this aspect to the persistent slab avalanche rose. 

An observer yesterday noted good stability on some southerly facing terrain while encountering an unstable snowpack on westerly facing terrain where they also remotely triggered a large avalanche. There is some good riding on southerly facing terrain right now, where you have a reduced risk of triggering an avalanche. Some southerly facing terrain is, of course, developing sun crusts, so it isn't a give me, but there is still some good quality snow that can be found. 

Avalanche conditions are far more complicated in the aspects highlighted by the persistent slab avalanche problem. In these areas, the snowpack is also slowly gaining strength with each passing day, and you may notice fewer obvious signs of instability. However, we are far from a snowpack that you should begin to trust. There will be continued avalanche activity on these buried, persistent weak layers, and if you get caught in one of those avalanches, it will be large and potentially deadly. Another factor that adds complexity to this avalanche problem is its spatial distribution across the terrain. In many areas, the slope may have previously avalanched, removing some of the necessary ingredients for an avalanche at this time. Some avalanche bed surfaces may have enough new snow that has filled back in for enjoyable riding. Be careful of the potential of being lowered into a false sense of security, as you will encounter more dangerous avalanche conditions when you cross a piece of hang fire or travel through a slope that hasn't recently avalanched. 

Regions covered