Avalanche forecast

Southeast Mountains

Crested Butte Avalanche Center
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Avalanche danger

Tue
Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
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Out of date — this forecast expired 8 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

Most slopes have a loose, cohesionless snowpack that is safe from avalanches, except for minor sluffing.  Isolated slab instabilities linger on steep slopes that saw significant previous windloading:  be cautious of high-consequence terrain where you find thicker, stiffer snow.   

Avalanche problems

  • Persistent Slabs

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

    Snowfall and wind drifting in early December formed slabs up to a couple feet thick over facets near the ground.  These weak layers are most widespread on the northern half of the compass and exist as collapsible crusts on some high-elevation southeast slopes.  In the Southeast Mountains, most slabs have decayed, and the threat lingers on a few heavily drifted slopes near and above treeline.  Stay alert for isolated instabilities and consider avoiding old stiff drifts above high-consequence terrain.  Most lingering instabilities are expected to be small (D1-D1.5), with potential for a larger outlier on the largest, most wind-drifted slopes.  

    A skier triggered persistent slab avalanche on Sunday, 12/14.  

    East aspect of Cinnamon Mountain. 

Avalanche Discussion

Observers reported a couple of notable avalanches yesterday: a skier-triggered persistent slab near Paradise Divide and what appears to be a recent natural persistent slab off of Cascade Peak.  Although reports of cracking/collapsing have waned to isolated or none in the past few days, these avalanches show the problem still exists.  The troublesome aspects are well defined by the pattern of persistent slab avalanche activity in the past two weeks and by thorough documentation of weak November snow surfaces before burial.  More recently, we've seen the issue become more confined to near and above treeline where slabs are robust enough to survive ongoing faceting.  

The early December storms added 3.5" of SWE at Irwin, whereas Butte Snotel at CBMR picked up 1.7" SWE onto a layer that was equally fragile across the forecast zone.  With roughly twice the snow load in the Northwest Mountains, slabs are both larger and more common throughout the terrain, and more resilient to the decaying process.  As time goes on and the snowpack continues to adjust, both zones are seeing a gradual decline in the danger.  The Southeast Mountains are the first to move to Low: fewer slopes harbor the problem, and where it exists, avalanches are typically smaller.  With thin snowpacks, even small avalanches that drag you over rocks and logs can have serious consequences, so don't let your guard down.  In the Northwest Mountains, travel in avalanche terrain requires a bit more caution for now, as slabs are typically thicker and more continuous across the terrain.

Regions covered