Avalanche forecast

Northwest Mountains

Crested Butte Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 6 years ago.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

Highlights

A Special Avalanche Bulletin is in place for the mountains surrounding Crested Butte.  Significant snowfall is overloading a weak snowpack and avalanches are likely.  Terrain from Kebler Pass through Paradise Divide through Schofield Pass is the most hazardous area as these locations received the most snowfall.  Expect that you can easily trigger avalanches that are large enough to bury you.  Continued snowfall on Saturday will increase the avalanche hazard throughout the day.  The terrain in the Southeast Mountains that border the Northwest Mountains are included in this Special Avalanche Bulletin.    

Avalanche problems

  • Persistent Slabs

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

    Friday's snowfall built slabs over previous weak snow surfaces.  Observers yesterday noted natural and human-triggered avalanches that propagated widely.  Some avalanches were triggered remotely.  Additional snowfall today will add more volume to this problem and increase the size of avalanches.  The largest avalanches are expected in the parts of the Northwest mountains on drifted terrain features at mid and upper elevations.  Even shallower soft slabs in sheltered terrain can entrain more volume than expected due to the entrainment of weak snow below the slab.

    Mid-track in Thanksgiving Bowl on Schuylkill Ridge on 12/11. The avalanche ran through everything in that direction and most of the slope behind the photo.

Avalanche Discussion

As you have read in the Bottom Line, there is a Special Avalanche Bulletin in place.  Friday's storm brought 12+ inches of snow to parts of the Northwest Mountains.  Today another storm will bring a second round of snowfall that is forecasted to produce close to the same amount.  Storm totals by the end of the day on Saturday could reach around 2 feet since Friday morning.  Terrain from the Kebler Pass area through Schofield Pass (the Ruby Range)  will represent the most dangerous locations.  Observers noted many small avalanches and some large size avalanches yesterday.  Expect conditions to worsen today as this round of snowfall stacks up.  If the weather forecast is exceeded then the avalanche danger has the potential to reach HIGH for parts of the northwest mountains.    

The greatest hazard will be in the Northwest Mountains.  Avalanches will be likely on drifted terrain features as well as sheltered slopes.  The largest avalanches will run on drifted terrain features at mid and upper elevations.  Expect drifted features to produce large, D2, avalanches which will be big enough to bury you.  In sheltered areas, slabs will be smaller, but the weak, old snow below is likely to be entrained as avalanches run and will create debris piles large than you would expect.  Conservative decision-making and thoughtful travel techniques will be required to manage the avalanche hazard effectively.  Expect dangerous avalanche conditions and choose terrain that will help to minimize the risk.  The simplest solution is to choose lower angled slopes without avalanche hazard above.  Poor visibility will make it difficult to see the terrain around and above you.  South and southwest facing terrain, prior to the storm, was dirt or melt/freeze crusts.  These aspects offer a reduced chance of triggering a dangerous avalanche as compared to the rest of the compass but are still suspect aspects. due to the significant snowfall.  

The Southeast Mountains received closer to 8 inches yesterday with an additional 6 inches forecasted for today.  Here the avalanche problems will be smaller in size, but still capable of entraining more mass than expected due to the weak snowpack below.  The border area of the Southeast where it meets the Northwest Mountains will be the most concerning.  This includes terrain on Mount Emmons, Anthracite Mesa, and Snodgrass Mountains.  Expect to find signs of instability and heed the warnings by minimizing your exposure to avalanche terrain.  Even though the avalanches will be smaller, they are still potentially dangerous.  

Regions covered