Avalanche forecast

Northwest Mountains

Crested Butte Avalanche Center
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Avalanche danger

Sun
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Recent storm snow and wind created sensitive drifts on leeward terrain features.  You can trigger slab avalanches in the new snow where winds have formed cohesive slabs.  On the northern side of the compass, there is a low probability of triggering avalanches on weak layers deeper in the snowpack, but the consequences remain high if you do.  You can reduce risk by steering clear of wind-drifted features and choosing more conservative terrain on northerly aspects to reduce the chances of a surprise large avalanche on older, deep, weak layers.  Wind-protected, southerly terrain offers a much lower risk of slab avalanche, but the sun may warm the new snow and create a minor loose avalanche hazard.

Avalanche problems

  • Persistent Slabs

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

    Slabs over buried weak layers 1.5 to 3 feet thick are typically stubborn to triggers, as the hard slabs are often insulating the buried weak layers from the weight of a human. Triggering would most likely occur from areas where slabs are thinner. Obvious signs of instability are rare to non-existent.  Persistent weak layers are buried in the middle and bottom of the snowpack. Avalanches can be remotely triggered from steep or adjacent flat terrain (see several videos illustrating this) and propagate widely through the terrain.  The most reliable strategy for managing this problem is to choose conservative slope angles or travel on southerly aspects.  On problematic aspects, avoid traveling in or near steep terrain where slabs are thin or variable in thickness, such as convexities, rocky areas, or wind-affected terrain.   

     

    A large persistent slab avalanche that failed around 2/25 near Purple Ridge. 

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Issues with the recent storm snow can be found on wind drifted terrain features.  Above treeline terrain is the most likely place to encounter fresh drifts, but you could encounter wind loading near treeline as well.  Forecasters triggered a few soft wind slabs on leeward terrain features of Cascade Mountain on Friday.  Expect these sensitive conditions to linger into Saturday.  Given the modest storm totals, 8 -12 inches, of low-density snow, the slabs are relatively small, but large enough to take you for a scary ride.  Carefully identify wind loaded terrain features and steer around recent drifting.  Shooting cracks are a clear sign of instability.  Wind speeds calmed overnight before the snow ended, so there could be a few fresh inches of snow obscuring the locations of drifts from earlier in the storm.

    (3/6/2026) A skier triggered wind slab on a drifted terrain feature near treeline.

Avalanche Discussion

The recent storm formed new avalanche problems.  Weather stations and observers have noted between 5 and 12 inches of low-density storm snow.  In wind-protected locations, you could encounter a minor loose avalanche issue on steep terrain features.  Slab avalanches can be triggered on leeward terrain features with fresh drifting.  Forecasters frequently produced shooting cracks and triggered a few small wind slabs near treeline on Cascade Mountain.  These drifts were very sensitive on Friday as they were forming and will likely remain that way on Saturday.  The recent storm snow accumulated on crusts on sunny terrain features and facets on northerly terrain features.  Expect the sensitivity of drifted slabs to last longer where they formed above faceted grains.

The trickier part of today's hazard comes from weak layers deeper in the snowpack, the persistent slab problem.  In the Northwest Mountains, the probability of triggering an avalanche on deeper weak layers continues to decrease due to thick, dense slabs and improving strength in weak layers.  Although the likelihood continues to drop, the consequences remain severe if you find the wrong spot and release a dangerous avalanche.  In the Southeast Mountains, the slabs are generally thinner, and weak layers have shown less improvement.  Additionally, the rain event on Wednesday, 2/25, had less impact on the snowpack in some parts of the Southeast Mountains.  This observation from Zach in upper Cement Creek provides evidence of increased sensitivity in persistent weak layers.  Rain crusts were much thinner in this area and added less strength to the snowpack than commonly found in the Northwest Mountains.  Some uncertainty exists about the impact of this storm's water weight on deeper weak layers.  The simplest solution is to select more conservative terrain for aspects and elevations highlighted by the persistent slab rose.

Regions covered