Bulletin d’avalanche

Northwest Mountains

Crested Butte Avalanche Center
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Danger d’avalanche

Sat
Alpin
4 · Fort
Limite forestière
4 · Fort
Sous la limite
4 · Fort
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Périmé — ce bulletin a expiré 4 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Strong winds and snowfall will rapidly increase avalanche danger on Friday morning.  As snowfall piles up, you can very easily trigger a dangerous avalanche and natural avalanches are likely.  Travel in avalanche terrain is not recommended.  Poor visibility will hamper your ability to identify overhead hazards in the field so make a thorough travel plan to avoid being directly below avalanche terrain.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    1.5–2.5

    A widespread weak layer was buried by a potent storm earlier this week and produced a significant avalanche cycle in the Northwest Mountains.  Today's storm will overburden the same weak layer and should produce another avalanche cycle.  Expect typical Persistent Slab behavior like wide propagation and remote-triggering of slopes from below or adjacent terrain.  Expect many avalanches to be large enough to bury and kill you.

    A widely-propagating avalanche failed during Tuesday's natural cycle.  Friday's storm will produce another round of avalanches like this.

  • Storm Slabs

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

    Today's storm will pile up snow during the first half of the day and the arrival of a cold front may produce a short period of intense snowfall before noon.  Anticipate easily triggering avalanches in the storm snow particularly in wind-drifted terrain and during periods of intense snowfall.  Human-triggered avalanches involving just the storm snow may grow large enough to bury and kill you.

    An example from December 2021 of a storm snow avalanche failing during a period of heavy snowfall.

Avalanche Discussion

An Avalanche Warning has been issued due to very dangerous avalanche conditions for the mountains surrounding Crested Butte.  Snowfall began around 2 am this morning and has been slowly piling up through sunrise with around 2-5 inches on the ground already.  Snowfall will continue through the early afternoon, but sometime this morning a cold front will begin sweeping through the area ratcheting up snowfall rates.  Since the snowfall will come over a relatively short time period expect rapidly deteriorating avalanche conditions.  More specifically, conditions will worsen this morning as you are out in the mountains.

Travel in avalanche terrain is not recommended today.  If you are heading into the backcountry, you can reduce your risk of avalanche involvement by planning ahead before entering the mountains.  Select locations that allow you to safely navigate around avalanche terrain even with low visibility.  Choose terrain less than 30 degrees in steepness and clear of overhead hazards.     

EVENTS:

  • Avalanche Awareness Night is December 3rd and Beacon Brushup is December 4th.  Details here.

Régions couvertes