Avalanche forecast

Southeast Mountains

Crested Butte Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

It remains possible to trigger a soft slab in this week's snow where previous drifts formed over facets, most commonly near and above treeline.  Recent human-triggered slides exemplify the problem, including one close call/ remote trigger near Marble.  Slabs are largest and most dangerous on wind-loaded slopes at high elevations - the safest riding is in wind sheltered terrain where slabs are rare.  On high, northerly aspects, there's a small chance you can trigger a much larger slab in steep terrain where snow depths are thin and variable.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2.5

    Windblown snow this week has formed relatively shallow soft slabs on terrain features favored by westerly winds.  These slabs have bonded well except where they formed over a thin layer of facets.  This layer is hit-or-miss in distribution, but we have found it on various aspects.  Carefully assess slab size and terrain consequences before riding in steep, leeward terrain. Expect spatial variability in how slabs bond; use small steep slopes to gather stability feedback.  Cracking or collapsing are obvious signs of unstable snow.  Slabs are rare at lower elevations.     

    There's a small chance you can still trigger a deep, persistent slab on high, northerly aspects where the snowpack remains winter-like. Terrain where the snowpack is unusually shallow due to wind effects or previous avalanche activity is most concerning.  Choose deeper, more uniform snowpacks over thin, rocky areas to reduce your risk.   

    An example of the type of avalanche that might remain sensitive to triggers on a high elevation, leeward slope.  

Avalanche Discussion

Now that a few days have passed since Tuesday's storm, most wind and storm slabs have healed.  However, instabilities involving the recent snow could linger where well-developed slabs formed over a layer of thin facets above the meltdown crust.   These facets formed from melt-layer recrystallization - a process that requires a specific set of ingredients that weren't widespread at the start of this week's snowfall.   In other words, the layer is spotty in distribution. We have found it on various aspects around the compass (ex. Baxter Basin and Elkton) and have also found it absent on those same aspects.  We have lower confidence describing where the layer is most likely to be found, but higher confidence describing where in the terrain slabs above this layer have formed.    In the Ruby Range, storm totals this week exceed 2" of Snow Water Equivalent, and slabs are fairly ubiquitous around the compass as you gain elevation into higher terrain.  As you move away from the favored Snowbelt, slabs have only formed on well-drifted slopes favored by westerly winds.  Carefully assess for the presence/absence of a slab and how the slab is bonding before riding in steep, consequential terrain.

High northerlies are the only slopes that didn't see extensive meltwater into the snowpack last week. On these coldest aspects, a more winter-like snowpack structure exists. This requires consideration for weak layers near the ground that have plagued us this winter, especially on terrain with unusually shallow snow depths. The most recent human-triggered examples of the problem include a snowmobile-triggered slide on Axtell and a skier-triggered slide on Gothic.   In the San Juans on Wednesday, a skier was surprised when they triggered a shallow wind slab that stepped down and produced a very large avalanche. 

It's that time of year when it doesn't take much sunshine to cause shallow wet loose avalanches in fresh snow.  Today's increasing clouds should hopefully limit the issue; the threat of wet loose avalanches involving the new snow will increase tomorrow and later in the week as the sun returns in full force and temperatures warm.  The instability is easy to recognize. Look for rollerballs, pinwheels, and natural sluffs as the snow surface gets damp.  

Events: CBAC's Party for the People is at the Talk of the Town next Thursday.  Come celebrate the end of the season with us!  (Don't worry, we'll be forecasting for at least a few more weeks.)

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