Avalanche forecast

Northwest Mountains

Crested Butte Avalanche Center
View on map

Avalanche danger

Mon
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
Open full map
Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

The snowpack teeters near the edge of failure on many slopes.  You can trigger a dangerous avalanche on all aspects and elevations.  Avalanches can be triggered from a distance and from below steep terrain.  Cracking and collapsing are clear signs you have found unstable snow, but the absence of these does not mean safer conditions.  Conservative terrain selection is your safest option.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–3

    The recent storm formed slabs 3 to 5 feet thick, overloading the widespread facets and faceted crusts that formed during our long December drought and weak layers at the ground.  These avalanches can propagate hundreds of feet wide and have been remotely triggered from thousands of feet away. This is a very challenging problem to manage; give yourself a wide margin for error when traveling near or below avalanche terrain.   The easiest and most reliable way to manage this problem is to ride on slopes consistently less than 30 degrees in steepness.  Other strategies for reducing your risk include riding on recent bed surfaces, but expert assessment skills are required for this.  

Avalanche Discussion

A week-long stormy period ended just a few days ago.  During this prolonged loading event over 200 avalanches were observed with far more going unobserved.  Avalanche activity spanned all elevations and occurred around the compass.  This helps illustrate the widespread nature of slab formation and weak layer distribution.  Concern for natural avalanche activity greatly diminished over the past two days, but the threat of human-triggered avalanches persists.  The threat of human-triggered avalanches even extends to the small hillsides surrounding and in the urban areas of CB and Mount CB.  A Special Avalanche Bulletin has been issued for the Southeast Mountains, where large slab avalanches are especially sensitive to human triggers right now, but you can find dangerous conditions in both forecast zones.

Recent observations suggest that in some places you may receive overt warnings of the danger with loud collapses as mentioned in this observation from Schuylkill Ridge. Other times you may not experience signs of instability before releasing a dangerous avalanche like in this observation from Mount Baldy on Friday.  In general, the shallower the snowpack the more likely you are to experience signs of instability and the deeper the snowpack the less likely you are to see these obvious warning signs.  Unfortunately, even in areas with a deeper snowpack human-triggered avalanches are a threat, you are just less likely to be warmed by the snowpack beforehand.  This observation from Kebler Pass illustrates this with snowpack tests from a couple of locations with varying slab thickness above the weak layer.  The weak layer in all locations continues to look poor and has yet to increase in strength.

Choosing lower-angled terrain will be the easiest and most reliable way to have a safe day in the mountains.  Some slopes avalanched late in the storm cycle and present a much lower likelihood of having an avalanche problem, however attempting to ride bed surfaces on recently avalanched slopes is challenging to do safely and requires an advanced skill set.  Low-angled terrain is riding great right now.

A weak storm system is moving into the area today, but only a few inches of snow are expected.  This minor load is not anticipated to have much impact on the already dangerous conditions.  Reduced visibility may make it harder for you to identify overhead hazards and potentially allow you to walk beneath terrain you'd otherwise avoid.  Plan your route thoroughly to avoid unintentionally triggering an avalanche from below.

 

Regions covered