Avalanche forecast

Northwest Mountains

Crested Butte Avalanche Center
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Avalanche danger

Sat
Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
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Out of date — this forecast expired 8 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

Up to 5 inches of new snow and gusty southwest winds may have formed small, shallow wind slabs on isolated leeward features at upper elevations. These slabs are generally easy to avoid—watch for recent drifting and steer around deeper wind-loaded areas. Older hard slabs linger beneath the new snow, and while they are isolated and mostly unreactive, even a small slide could have serious consequences in exposed or extreme terrain.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1–1.5

    An extreme wind event last week formed a few thin, hard slabs scattered across all elevations, in concave catchments and behind abrupt transitions in the terrain. Where these drifts formed over facets on colder aspects, you might still be able to trigger one, and they're stiff enough to knock you off your feet.  Look for firm, rounded snow surfaces to identify potential features of concern.

    Snowfall and wind drifting in early December formed slabs up to a couple of feet thick over facets near the ground.  These weak layers are most widespread on the northern half of the compass. Mild weather through the middle of December has helped the snowpack adjust to its current load, and in many areas, the slabs have decayed or been scoured away by winds. The last documented avalanche on these old, weak layers was accidentally triggered on 12/14.  Similar instabilities will be very rare, but not impossible.  

    An example of a thin, hard slab over sugary facets.  A few inches of snow and wind on Christmas may obscure the visual clues of older, hard slabs. 

Avalanche Discussion

Initial reports indicate the Grinch rain event produced liquid precipitation up to nearly 11,000 feet—a truly unusual storm. Cooler temperatures yesterday afternoon allowed wet surfaces to refreeze, hopefully eliminating wet avalanche concerns for today. At the highest elevations, precipitation fell as snow, with totals of roughly 5 inches.

Avalanche problems are sparse across the landscape, and conditions are generally safe. The primary concern is isolated wind-drifted snow. Any fresh wind slabs formed by yesterday’s drifting are expected to be small and easy to avoid given the limited new snow. Look for the deepest accumulations on leeward features above treeline and steer around them, especially if you observe cracking in recently drifted snow.

Confidence is increasing in a stronger storm system arriving this weekend. Light snowfall is expected tonight, followed by a much more substantial pulse from Saturday afternoon through early Sunday. Favored areas could see storm totals exceeding a foot by Saturday evening. Expect avalanche conditions to change as new snow and wind begin forming more cohesive slabs over the next few days.

Regions covered