Avalanche forecast

Northwest Mountains

Crested Butte Avalanche Center
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Avalanche danger

Mon
Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
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Out of date — this forecast expired 6 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

You'll find the safest riding conditions at higher elevations and in terrain where the snow is denser and more supportive.  We continue to receive reports of natural or human-triggered dry loose avalanches on a daily basis from steep terrain that faces north or east. Most of these are harmless in size, but in larger avalanche chutes, facet sluffs are entraining the whole snowpack with enough umpf to drag you through rocks and ruin your winter before it even begins.   The problem has been smaller and less widespread in the Northwest Mountains, where the avalanche danger is rated LOW.    

Avalanche problems

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    On very steep terrain sheltered from the sun and wind, you can easily trigger sluffs where the snow surface is loose and cohesionless. This skier triggered slide on Schuylkill Ridge on Thursday highlights the problem.  In the Northwest Mountains, loose dry avalanches have been smaller and easier to manage, entraining just surface snow in the upper snowpack.  They can still present a hazard if you get pushed into trees or rocks, so be mindful of terrain consequences in terrain steeper than about 37 degrees.  

Avalanche Discussion

Yesterday, Crested Butte's low temperature was -5 degrees, and the mercury swung to 32 over the course of the day.   Dramatic diurnal temperature swings like that, paired with clear, cold nights, are driving rapid faceting throughout the snowpack.  As the snowpack weakens, it becomes more susceptible to sluffing.  This pattern has been on-going for almost two weeks. The weakest snowpack has been on the shady slopes near town, where the inversions and large diurnal temperature swings have been most pronounced.  In the Southeast Mountains  (terrain like the Happy Chutes and Climax Chutes on Mountain Emmons), skier triggered facet sluffs have entrained the whole snowpack with enough volume to injure you if you get caught (Example A, Example B).  Sluff management techniques are less practical in terrain where the snowpack is rotten bottom to top: the sluffs wipe away the whole snowpack leaving you with just rocky turf to descend.  Like a plague, the decaying snowpack is spreading further up valleys and to areas that were offering a stronger, more cohesive snowpack last week.  Recent dry loose slides in Schuylkill Ridge and Baxter Basin demonstrate how the problem also exists in the Northwest Mountains; so far, these slides have been easier to manage because they aren't gouging to the ground.  I suspect in some terrain features, that has now changed.    Warming temperatures over the last few days have also initiated a few natural sluffs from steep, rocky areas catching sunlight.  These were all quite small.  The subsequent size of any sluff today will depend on how much loose snow there is and how long the terrain is.  If you find yourself sinking past your boots in bottomless sugary snow, you can easily avoid the problem by moving to lower angled terrain or to slopes where the snow surface is denser and stronger.  

Regions covered