Bollettino valanghe

Northwest Mountains

Crested Butte Avalanche Center
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Pericolo valanghe

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In sintesi

Generally safe avalanche conditions exist in the Northwest Mountains.   Be cautious in steep, shady terrain where triggered sluffs may have the potential to entrain more snow than expected and drag you into rocks or trees.  Sluffs will be more common as you descend to near or below treeline slopes, where the snow is softer and unaffected by previous winds.  

Problemi valanghivi

  • Loose Dry

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    Probabilità
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    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 yesterday 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

We've made a few changes to the zone forecasts to keep stride with a continually weakening snowpack, a product of our dry weather and cold nights.  Our forecast team was above Peanut Lake Road yesterday and got direct feedback that the dry loose facet sluffs are now entraining the entire snowpack on below treeline slopes (see observation).  This problem is most pronounced and most widespread on shady slopes near town, where the strong inversions have been quicker to rot out the entire snowpack.   The continued spell of dry weather with the facet machine turned on high means that the number of problematic slopes and the expected size of avalanches are both increasing.  Thus, we raised the danger to MODERATE on below treeline slopes in the Southeast Mountains (the terrain near and south/east of town, see map), where the problem is most concentrated.  While most sluffs will still be small, we suspect you could trigger a large (D2) dry loose avalanche in longer running terrain like Climax Chutes.  We've also expanded the dry loose problem into the Northwest Mountains because we expect some of the near and below treeline terrain in the bordering areas of the zone will start to exhibit similar issues.  As you move further up valleys away from the inversion, or into the alpine, the snowpack is denser and stronger, and full-depth sluffing becomes a rare or non-issue.  At locations such as the Upper Slate, we've observed just minor sluffing in the top 3" to 6" of surface facets on top of a strong, supportive snowpack.       The travel advice for managing our current facet sluff problem is pretty simple.  Plan your routes in terrain where the snowpack is denser and more supportive.  If you find yourself wading through bottomless facets, you're likely to trigger a full-depth sluff on slopes steeper than about 37 degrees.  A ski cut or two will mitigate the risk, but unfortunately, it will also  flush all the snow away and leave you with bare ground to descend.  A better solution then is to steer towards lower slope angles so you have some snow to ride on, if that's your jam.    

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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