Avalanche forecast

Northwest Mountains

Crested Butte Avalanche Center
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Avalanche danger

Fri
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Heightened avalanche conditions exist on wind-loaded terrain features, where you can trigger slabs in the recently drifted snow or, in isolated areas, older harder slabs.  Be cautious of leeward slopes below corniced ridgelines, in crossloaded gullies, or other features that collect drifting snow.  Wind-sheltered terrain offers higher snow quality and safer riding. 

An Avalanche Watch is in effect through Saturday.  A potent winter storm will cause very dangerous avalanche conditions on Friday and Saturday. Travel in avalanche terrain is not recommended during that time.

Avalanche problems

  • Wind Slabs

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

    In the Northwest Mountains, around a foot of recent snow has drifted into stiffer slabs over crusts and facets in leeward terrain from west to northwest winds. Some of these will be stiff and stubborn, others easy to trigger.   Look for thicker, denser drifts and cracks in the snow to identify the problem.  Seek out softer snow in wind-sheltered or wind-eroded terrain to avoid the problem.  Evaluate slab size and terrain consequences before crossing any leeward terrain. 

    A small, skier triggered wind slab on a crossloaded slope yesterday.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1.5–2

    Old hard slabs up to several feet thick are isolated and difficult to trigger. You are unlikely to see signs of instability before triggering an avalanche that breaks on old, weak layers. The most likely trigger points would be where these hard slabs thin near their margins, on convexities, or near rocky areas, or a shallow wind slab could step down. Recent snowfall and wind drifting may have obscured the surface clues, making identification of old, hard slabs difficult: they're most likely lurking in concave features at higher elevations on the north half of the compass.

    This hard slab was triggered near Pearl Pass on 2/3.  This location is just beyond the CBAC's Southeast Mountain forecast boundary. 

    Photo: CAIC

Avalanche Discussion

Observers yesterday reported a handful of triggered and natural wind slabs breaking on leeward slopes from the ongoing west to northwest winds.  Most of these were small in size, but one that ran down the east face of Gothic likely grew larger.  With strong winds continuing overnight, slabs will be thicker and stiffer today, and more difficult to manage. There's also isolated step-down potential involving older harder slabs like this avalanche on the Aspen side.  Wind-sheltered terrain has softer snow and offers better riding quality, free of these issues.  Most sheltered slopes still lack a slab (ex. Schuylkill Ridge), though in a few favored areas in the Northwest Mountains, you may encounter shallow and soft storm slab instabilities (ex. Anthracites) that will be easier to manage than our wind slab problem.  

As a result of one of the driest winters on record, paired with two extensive avalanche cycles this season, our snowpack in steep terrain is unusually shallow and weak.  From our "deep" zone to our shallow zone, from alpine to valley floor, the snowpack structures on many west, north, and east-facing slopes are almost entirely weak facets, capped by collapsible crusts in some terrain. These structures are now getting buried by this week's snowfall and wind drifting (See video from Cement Creek, or this pit from Schuylkill Ridge, as just a couple examples).  Under the intense loading that starts tonight and continues into Saturday, widespread instabilities will develop.  These unusually weak and crusty snowpack structures could produce unique or surprising avalanches.  For example, the Marble side, which has picked up a bit more snow than we have this week, saw an avalanche in the recent snow propagate widely across most of a bowl yesterday.  That's a small taste of what we will see early on Friday, and slabs will only grow thicker and propagate wider as the Cupid Crush rages on. A large and widespread avalanche cycle is expected.  Travel in or below avalanche terrain is not recommended during the storm on Friday or Saturday.  Reign in that powder fever - it will be a great weekend to ride the low angle free of overhead hazards or head to the ski resort.

Upcoming Event - Open the storm floodgates with the Floodgate Operators at the Public House on Saturday, February 15. Tickets are available here.  Proceeds from the show to benefit the CBAC.

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