Bulletin d’avalanche

Southeast Mountains

Crested Butte Avalanche Center
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Danger d’avalanche

Sun
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 7 months ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Heightened avalanche conditions exist at mid and upper elevations, where previously wind-loaded slopes will dictate how you move through the terrain. Easterly and southerly facing slopes at these elevations received the most wind loading last weekend, but you might find cross-loaded features on other aspects. To reduce your chance of triggering a slab avalanche, consider avoiding the stiffer snow found below some ridgelines and cross-loaded terrain features. In wind-sheltered areas, northerly-facing slopes offer soft riding conditions, where small dry loose avalanches are the primary concern on steep terrain.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    Most avalanche concerns today involve slabs of drifted snow that formed over the facets and faceted crusts from our January drought.  These slabs, typically less than 2 feet thick, could remain sensitive to human triggers on some leeward terrain features, most commonly on east to south-facing aspects at higher elevations and on crossloaded features elsewhere.  Because these recent slabs formed on highly variable snow surfaces, expect hit-or-miss feedback as you move through the terrain.  Collapses and shooting cracks are clear red flags. There is isolated potential for a slab failing in the upper snowpack to step down and trigger a deeper, harder avalanche near the ground. Searching for wind-eroded and soft wind-dappled snow will help reduce your exposure to this avalanche problem, while the best way to avoid it is by riding in wind-sheltered areas. 

     

    Several large avalanches that failed a week ago on wind-loaded southeast-facing slopes in the NW Mountain forecast area.

  • Loose Dry

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–1.5

    The upper snowpack is losing strength and has begun to sluff on steep slopes. This small avalanche problem is the most common at lower elevations, where the cold valley inversions have created the weakest snowpack. Most of these triggered avalanches will be relatively harmless, but where they run through sustained steep terrain, they can become larger in size, and they could push you into more hazardous terrain features, such as trees, or pile deeply in terrain traps. 

    A small dry loose avalanche near Peanut Lake. 1/30.

Avalanche Discussion

The best riding and softest powder can be found on northerly facing wind-sheltered terrain at lower elevations. Given the reduced avalanche hazard here, this is a good time to get out and enjoy the backcountry in those areas. Small loose dry avalanches are starting to creep into the problem list as the snowpack loses strength in these wind-sheltered areas. These sluffs are the most common in the SE Mountain forecast area, where the snowpack is thinner. In the NW Mountain forecast area, the upper snowpack is still holding some cohesion, helping to hold back these sluffs. Exceptions exist in the NW Mountain forecast where the snowpack is below average in depth, like on an old avalanche bed surface. There, small sluffs will be more common, and conditions will be similar to the SE Mountain forecast area.

With nice weather this weekend, you may want to climb higher in the terrain. In these more wind-exposed areas, the avalanche danger is on a gradual downtrend after last weekend's loading event and natural avalanche cycle. However, forecasters have experienced collapsing while traveling in near and above treeline terrain, often on easterly and southerly aspects (Galena, Wolverine Basin).  Weak snow is common beneath last weekend's storm, while prevailing winds from the northwest primarily loaded easterly and southerly aspects.  The avalanche activity rose highlights this pattern of increased avalanche activity on wind-drifted easterly and southerly terrain.  You should expect to find drifted slabs on westerly and northerly aspects, but less frequently, and often due to crossloading.  The avalanche activity and signs of instability suggest a cautious approach to terrain with evidence of previous drifting.  This video shares more information about the concerning structure Zach encountered in Rock Creek while investigating a natural avalanche.

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