Avalanche forecast

Northwest Mountains

Crested Butte Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 3 years ago.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

Highlights

An AVALANCHE WARNING is in effect. Very dangerous avalanche conditions exist. A natural avalanche cycle is ongoing, and it will also be easy to human trigger avalanches. These avalanches can be remotely triggered from flat terrain below steep slopes, and a triggered avalanche can further propagate widely through the terrain. Travel in or below avalanche terrain is not recommended. 

Avalanche problems

  • Storm Slabs

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

    Overnight snow totals are difficult to verify this morning. ~10 to 16 inches of snow has likely accumulated in the last 12 hours with more in the forecast. Temperatures have been increasing during this time, creating the potential for heavy snow on top of lighter snow. Strong westerly winds have further created thicker slabs on the lee sides of terrain features. These avalanches will break within the recent storm snow, or on the persistent slab avalanche problem below. 

     

    Shooting cracks near Gunsight Bridge. 1/13

    Photo: Evan Ross

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    2–3

    2 to 3 feet of snow has accumulated on widespread persistent weak layers such as fragile facets and faceted crusts. These avalanches are propagating hundreds of feet wide and being remotely triggered from thousands of feet away. This is not a manageable avalanche problem. Avoidance is the travel advice. Very large avalanches will run naturally today.

    On Friday, this avalanche was 650 feet wide! No way you are riding out of that one. 

Avalanche Discussion

We are in it! The weather outside is beautiful, however, the avalanche conditions outside are ugly and absolutely dangerous. If you haven't been following along this winter, we have had a well below-average snowpack. Long dry spells in December and early January have created persistent weak layers around the compass. Those weak lanyers are now being overloaded by the biggest storm we have seen in months. The result is the ongoing natural avalanche cycle and easy human triggers. We do expect some very large D3 avalanches to occur during this avalanche cycle. Some avalanches could impact backcountry roads. We don't otherwise have enough snow to lead to a historic valley-crushing event. 

Some of the remote weather stations appear to be lagging behind this morning and not reporting well on the recent snow. Since January 12th, the Irwin Lake weather station has increased by 1.7 SWE and the Butte Snotel has increased by 1.2 SWE. The greatest portion of this loading event occurred last night and is ongoing this morning. Recent strong to extreme winds have further loaded the lee sides of terrain features, even at some valley elevations. 

Forecasted snowfall starts to taper off tonight and further decreases tomorrow. For below treeline elevations, the avalanche danger will start to slowly trend down once we move beyond today's peak loading. The below treeline elevation danger ratings will be reassessed tomorrow morning with updated weather forecasts. Otherwise, the wind is expected to continue driving HIGH avalanche danger through Monday. 

Regions covered