Avalanche forecast

Northwest Mountains

Crested Butte Avalanche Center
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Avalanche danger

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

The hits keep coming, and our meager and weak snowpack will be struggling today.  Significant wind transport yesterday puts leeward terrain in the bullseye for dangerous conditions: slabs can break in the newly drifted snow, or step down into older weak layers producing a much larger avalanche.  Choose conservative terrain near and above treeline.   At lower elevations, slabs are less common, and old faceted rain crusts have done a better job of supporting recent snow loads.  Carefully assess the snowpack and watch for obvious signs of instability, especially as you climb above 10,500'. 

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1.5–3

    A mix of facets and faceted crusts buried 2 to 4 feet deep continues to produce large human and remote-triggered avalanches. Northerly and easterly facing terrain near and above treeline has been most active due to thicker slabs over well-developed weak layers. The lower half of the snowpack is highly variable, shaped by early-season droughts, record-warm temperatures, rain, and past extreme wind events. As a result, expect inconsistent feedback as you move across aspects, elevations, or even different parts of the same slope. Obvious signs of instability may be absent, and the first clear signal could be a dangerous avalanche. The most reliable way to manage this problem is by choosing slopes less than 30 degrees. Wind-eroded terrain, sunnier aspects, and lower elevations generally offer lower risk options, where slabs are less common and weak layers are often capped by thick crusts. 

    A large, remotely triggered avalanche on Schuylkill Ridge on Sunday.(1/4/2026) Photo: Crested Butte Avalanche Center

  • Wind Slabs

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

    About a foot of new snow and strong southwest-to-west winds yesterday formed sensitive slabs in leeward terrain features at higher elevations.  Slabs will be most common below corniced ridgelines, in cross-loaded gullies, and behind abrupt terrain transitions.  Read wind drifting patterns and avoid pillows of thicker, stiffer-feeling snow.    Wind slabs formed on the most problematic aspects for deeper weak layers: a relatively shallow instability in the new and drifted snow could step down and trigger a much larger avalanche. We saw dozens of step-down avalanches during our previous storm last Friday.  

    In this photo, you can see a thin wind-drifted slab that started at the ridgeline and stepped down to trigger a larger persistent slab.  Similar activity can happen today.  Photo: Crested Butte Avalanche Center

Avalanche Discussion

Yesterday's storm finished with a similar SWE load as Friday's storm and notable cycle in the Ruby Range: up to 1.2" in the Northwest Mountains and up to .7" in the Southeast Mountains.  This storm brought stronger, more productive wind speeds (see Irwin's observation). Alpine stations were averaging an ideal 20 to 30 mph from SW to W, loading onto our most worrisome aspects.  If visibility allows, it will be interesting to see how our snowpack responded.  We expect many wind-loaded slopes to be near their human-triggering tipping point, with the potential for the largest persistent slab avalanches in the Ruby Range (mostly D2-D2.5, isolated D3 potential).   We've had very few field visits to the higher terrain east of town, and our uncertainty there is greater.  We know the snowpack was exceptionally shallow and weak going into the start of our loading period on Christmas, and stress over those layers is gradually building, especially on slopes favored by yesterday's productive wind drifting.  SWE totals on our December dryspell layer (the Christmas facets and crust/facet layers) now range from 3.8" (Schofield) to 3.9" (Irwin) in the Northwest Mountains, and 1.5" (Butte), 1.9" (Upper Taylor), ~2.2" (Gothic), and 2.8" (Castle Peak) in/near the Southeast Mountains.  Bottom line: as you gain elevation and as you move further from the middle of the CB donut hole, expect increasingly dangerous conditions.  

Below treeline has been remarkably quiet in the past few weeks, with only a few small avalanches reported below 10,800'.  With each loading event, our uncertainty about the faceted rain crust waking up increases.  The crust is thinnest and most collapsible as you gain elevation closer to treeline, and slabs are more developed the higher you go: that's where I expect the first surprises to occur.  If you are riding in steep, wind-sheltered terrain at lower elevations, stay alert for signs of instability and evaluate both slab size and terrain consequences. 

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