Avalanche forecast

Northwest Mountains

Crested Butte Avalanche Center
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Avalanche danger

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

Remember all the avalanches that fell down in December? Well, here we go again. Dangerous avalanche conditions are developing and it is imperative that you keep that powder fever in check. The current snowpack is again extremely weak. We have seen steady light snowfall over the last several days, and now a bigger pulse of snow overnight and into Saturday. Natural avalanche activity will start ramping up, while human triggered avalanches will become likely today. You can enjoy the fresh snow, but you must do so with a conservative mindset. Keep those slope angles in check, and consider overhead slopes for natural avalanche activity. 

Avalanche problems

  • Storm Slabs

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

    In the northwest mountains, recent new snow accumulations are nearing 8 to 14". Soft slab avalanches are expected to release within this new snow, or in the upper snowpack. Don't be fooled by the soft nature of these slabs. The old snowpack is very weak, and these soft slabs may propagate widely across a slope, or they could be remotely triggered from lower angled slopes near steeper slopes. Once an avalanche initiates, it may entrain the old snowpack and grow much larger in size. Upper elevation winds will further increase the depth and size of these slabs near ridgelines at upper elevations. 

    Example of soft slabs failing on the old snow surface in early December.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

    The current loading period is adding stress to persistent weak layers buried in early December. On these aspects, it remains possible to trigger a slab avalanche that releases near the bottom of the snowpack. You will not observe obvious signs of instability for this avalanche problem. So it is imperative to keep in mind that these slabs would break 2 to 4 feet thick and instantly become large in size. The most concerning slopes are on northeast, east, and high southeast facing terrain.  You may be able to find isolated exceptions to the distribution rose on cross-loaded terrain features on other shady aspects.  

    Example of a large natural avalanche that released deeply into the snowpack earlier this winter.

Avalanche Discussion

Back in December, just as soon as we saw a snowpack building on those weak layers, a small avalanche cycle began. Those avalanches then grew in size as the snow accumulated and were problematic throughout the whole month. From the start of January through January 19th, the dry weather redeveloped a similar very weak snow surface, to what we had at the start of December. The only real difference is that this time that weak snow is more widespread around the compass thanks to better snow coverage. Widespread near surfaces facets cover many slopes, or there is a windboard with facets above and/or below, or there are collapsible crusts sitting over very weak facets. It's a junk show out there folks. So it's time to real in those terrain choices, and settle in for what will become the next long cycle of avalanche activity. 

Several weather stations are down at the moment. Yesterday, observers reported about 6 to 7" new snow had accumulated on the 1/19 interface in the NW Mountains. Closer to Crested Butte those numbers were closer to 3 to 4". We have no current data for the further east SE Mountains. The overnight snow accumulations that we do have are Schofield Pass with ~6" with .4SWE and CBMR with 3" on the pow cam at 5am. A caretaker just reported 1.5" of new snow at Cement Creek Ranch.

Alpine winds overnight were generally light from the south to the southwest. Those winds are expected to increase today from the southwest to the west. At 12,000ft winds could gust into the 50's. Those winds will be drifting snow and likely spurring on some natural avalanche activity today. 

Regions covered