Boletín de aludes

Northwest Mountains

Crested Butte Avalanche Center
Ver en el mapa

Peligro de aludes

Mon
Alta montaña
3 · Notable
Límite del bosque
3 · Notable
Bajo el límite
2 · Moderado
Open full map
Desactualizado: este boletín caducó 2 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

Continued strong winds and more snowfall keep the threat ongoing of large natural or triggered avalanches at higher elevations, in line with the pattern of slabs breaking up to several feet thick over the past few days.   Stay away from wind-loaded slopes for a more pleasant and safer day in the backcountry. Although avalanche conditions aren't as dangerous at lower elevations protected from the wind, stay cautious: a skier was caught and carried in a 2-foot slab below treeline Friday near Camo Glades.

Problemas de aludes

  • Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1.5–2.5

    Snow and wind-loading in the past week have formed a new generation of slabs up to several feet thick over small-grained facets in the upper snowpack.  Numerous natural and triggered slabs have occurred on this layer in the past few days.  Slabs are larger and most active near and above treeline on wind-loaded slopes, especially on colder aspects.  Avoid windloaded slopes today, while staying alert for potential instabilities on wind-sheltered terrain.  

    On unusually shallow slopes, most commonly in the Southeast Mountains, there is still a small potential to trigger a destructive avalanche that breaks on deeper weak layers. The most concerning structures are on northerly aspects near and above treeline where snow depths are less than 170 cm, or where large cornices fall onto slopes.  

  • Wind Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Likely
    Tamaño
    1–2

    Strong winds have been transporting snow over the past few days and will have more fresh snow available for transport today.  Prolonged wind drifting has created multiple generations of soft and hard slabs, some are sensitive to triggers, and others are more stubborn.   Wind slabs will be most common below ridgelines, behind rollovers or tree fences, and in crossloaded gullies.  Blowing snow and cracking in the snow are signs of danger.  Wind slabs could be dangerous by themselves, or they could step down and trigger a larger persistent slab avalanche described above.  Seek out softer snow in terrain protected from the wind to avoid the problem, or travel on windward features at higher elevations. 

    A wind slab on Crystal Peak.

Avalanche Discussion

More large natural activity occurred yesterday as winds increased, such as these slides near Mt. Tilton and Crystal Peak, on the heels of numerous large avalanches that likely ran on Friday, such as this D2.5 in Redwell Basin.  Relentless wind drifting in the past week continues to stress the March dry spell layer now buried up to several feet thick.  Today's wind loading will form yet another generation of sensitive wind slabs, adding to the stack of harder and more stubborn slabs that formed over the past few days.  In windloaded terrain, persistent slabs are getting harder, thicker, and more difficult to manage. The warm, windy weather is ideal for large cornice falls, which can also trigger larger slab avalanches.  With today's flat light and variable snow quality up high, it's an easy decision to head towards the safer and softer riding in wind-sheltered terrain.  

In the past week, only a few slab avalanches have been triggered in wind-protected terrain below treeline.  Signs of instability, avalanche observations, and stability tests all point to our persistent slab problem being less common at lower elevations.  However, some problematic slopes are out there, highlighted by Friday's avalanche triggered near Camo Glades.   Below treeline, the March dry spell layer is about 2 feet deep in favored parts of the Northwest Mountains, and less than 18" in the Southeast Mountains.  Stay alert for signs of instability, and use stability tests or small terrain features to gather more information before riding in higher consequence terrain.  Consider overhead hazards from windloaded slopes above you.    

Regiones cubiertas