Bulletin d’avalanche

Northwest Mountains

Crested Butte Avalanche Center
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Danger d’avalanche

Fri
Alpin
1 · Faible
Limite forestière
1 · Faible
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 6 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Generally safe avalanche conditions exist in the Northwest Mountains.  Be wary of northerly and east-facing terrain near and below treeline where you find weak, faceted snow as a triggered Dry Loose avalanche could entrain just enough snow to knock you down and push you into rocks and trees.

Problèmes avalancheux

  • Loose Dry

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

    On very steep terrain sheltered from the sun and wind, you can easily trigger sluffs where the snow surface is loose and cohesionless.  Several skier-triggered sluffs on Tuesday in the Southeast Mountains highlight how these avalanches may have the potential to entrain the entire snowpack on some slopes.   Be cautious descending confined gullies or in terrain where a loose avalanche could push you into trees or rocks.   You've found the problem if you find yourself sinking past your boot tops in loose, sugary snow.  Avoid trouble by moving to terrain less than 35 degrees or by moving to a sunny aspect.

Avalanche Discussion

The dry and cold conditions have been taking a toll on the snowpack around Crested Butte.  CBAC forecasters recently have been traveling through northerly and east-facing terrain observing a weak and faceted snowpack at low elevations.  You can check out recent observations from Happy Chutes(Mount Emmons) and Mount Axtel.  It was easy for forecasters to intentionally trigger Loose Dry avalanches in both areas with terrain closer to town and closer to valley bottom having the largest potential avalanche size as the snowpack is the weakest in these areas.  For terrain outside of the inversion zone, like Mount Axtel, the Loose Dry avalanche problem remains smaller for the time being.  The increase in likelihood and size of Loose Dry avalanches in the Southeast Zone required the danger rating to be raised to MODERATE for terrain below treeline on Tuesday.  Currently, the Loose Dry avalanche problem is small enough for the danger rating to remain at LOW for the Northwest Zone.  The weather is expected to remain dry and clear which will continue to weaken the snowpack in the coming days.  Northerly and east-facing terrain at higher elevations have weak faceted snow near the surface but possess stronger snow underneath which has resulted in only minor Loose avalanches in the past few days.  Southerly facing slopes are shallow but crusty and provide more support to skis or board and do not have a Loose avalanche problem.   Plan your routes to avoid areas where you are most likely to find the Dry Loose avalanche problem.  Sunny slopes and terrain at higher elevations offer a stronger snowpack that greatly reduces the chance of you triggering a Dry Loose avalanche and provide more support to skis and board.  If you find a shallow, faceted snowpack, less than about 20 inches, that provides no support underfoot then you are likely to trigger a Dry Loose avalanche on slopes steeper than about 37 degrees.  The simplest solution is to avoid this type of steep terrain.  It is challenging and dangerous to play in a shallow snowpack that can't keep you off the ground and hidden objects.  Take a look at this observation from Axtel to see a photo of the poor riding conditions on steep, shady slopes with a shallow, weak snowpack.    

This Friday is CBAC's Virtual Avalanche Awareness Night!  The event includes avalanche talks, drive-through food and swag, an awesome gear raffle, and an "Ask a Forecaster" panel -  all broadcast live from the Center for the Arts with your favorite wacky host, Than Acuff.   Tune in on our YouTube channel from 6 to 8 p.m on Friday.  

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