Boletín de aludes

Northwest Mountains

Crested Butte Avalanche Center
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Peligro de aludes

Tue
Alta montaña
3 · Notable
Límite del bosque
2 · Moderado
Bajo el límite
2 · Moderado
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Desactualizado: este boletín caducó 9 months ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

The new snow will be sensitive to human triggers where it fell on old, sugary snow - typically on the north half of the compass.  Remote triggering yesterday foreshadows what you'll find today.  Storm totals are deeper, and there's potential to trigger larger avalanches as you gain elevation.  The safest travel is on slope angles less than 30 degrees or on terrain that was bare ground before the storm.  

Problemas de aludes

  • Storm Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Likely
    Tamaño
    1–1.5

    It will be easy to trigger soft slabs about 12" to 16" thick on the north half of the compass, where the new snow accumulated on fragile facets.  Beware of remote triggering potential on steep slopes above you.  Shooting cracks and recent avalanche activity are clear signs of instability: manage the problem by choosing smaller, less consequential terrain or lower slope angles.   You can reliably avoid the problem by traveling where the new snow fell on bare ground on southerly aspects.  Some high, southerly aspects held old crusts before the storm: evaluate how well the new snow is bonding to these crusts before committing to steep terrain.  

    (11/30/2025)

    A small, remotely triggered slab on a north-facing slope NTL early in the storm.  

    Photo: Crested Butte Avalanche Center

  • Persistent Slabs

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

    Below the new snow,  dense old slabs one to two feet linger on previously drifted, high-elevation northerly slopes.  An avalanche in the storm snow could step down and create a larger-than-expected avalanche.  Beware of previously cross-drifted terrain in high northerly areas that attract early-season riders; these features might have the wrong ingredients of a harder slab over old faceted October snow.  Large collapses, like this observation from Cinnamon, are clear signs you’ve found this problem.

    A remotely triggered slab on the north side of Mt. Baldy on Nov 22.  This slope held an old layer of weak snow from October's snowfall, buried beneath 1 to 2 feet of drifted snow.  

Avalanche Discussion

It's nice to feel like winter is back, but let's start with the reminder that our snowpack is well below average for this time of year. Getting caught in any avalanche, large or small, will drag you over rocks, stumps, and early-season obstacles.   With the new snow accumulating on a fragile weak layer, we're dealing with sensitive conditions, but relatively small size.  Yesterday's observation from Bellview highlights our problematic weak layer, which was already producing remote triggers halfway through the storm.  Conditions are most dangerous in the snow-favored Northwest Mountains, where storm totals likely exceeded 18" at higher elevations and slabs could connect across more of the terrain.  This is also the same area where we have lingering concerns for older, denser slabs now well-hidden below the new snow on northerlies, making for more complicated travel management.  So far, winds have been unusually tame in the Ruby Range/Paradise Divide areas, but if winds increase, we could see some natural releases today.    

We have high confidence that slabs of new or drifted snow will be unstable where they formed over weak facets on the north half of the compass.  An area of uncertainty is how well the snow bonded to crustier surfaces that survived on high southerlies.  If you are avoiding the most reactive slopes and traveling on southerlies, assess how well the snow is bonding to old crusts.  We are most concerned about terrain where the crust is thin and collapsible (most often on southeast aspects).  

Upcoming Events: 

  • Holiday Tree Sale: December 3rd-5th from 3 pm-7 pm at Ace Hardware
  • Avalanche Awareness Night: Saturday, December 6th, at the Center for the Arts
  • Beacon Brush-Up: Sunday, December 7th at the Community School

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