Avalanche forecast

Summit Lake

Chugach National Forest Avalanche Center
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Avalanche danger

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

The combination of outflow winds and buried weak layers in Summit Lake is creating a potentially touchy snowpack setup. Human-triggered avalanches up to 1' deep in areas with recent wind loading are likely, and natural avalanches are possible. Weak layers up to 3' deep could cause larger avalanches at upper elevations. The ongoing glide avalanche cycle has caused very large and destructive avalanches throughout the region. We recommend you avoid travelling under glide cracks as much as possible.  

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–2.5

    Recent Avalanches: It has been about two weeks since the last known avalanche activity on buried weak layers in Summit Lake. Since then, we have seen mostly glide avalanche activity.

    The cold and clear weather has taken hold and doesn't want to let go. During this period of prolonged high pressure, our main concern is several lingering buried surface hoar layers that formed in November and are buried up to 3' deep. Triggering an avalanche on these weak layers is slowly becoming less likely, but there is a reason they are called persistent weak layers. They can sit in the snowpack for weeks or longer and still cause large avalanches with no warning signs. 

    These weak layers are only a concern above 2500', but that is also where the good snow conditions are. Digging snow pits can be a good way to identify and assess locations where these weak layers still exist. However, the signs can be very subtle, and even avalanche professionals can get unreliable information from digging pits with this type of weak layer. The best way to avoid the problem entirely is to stick to simple terrain with low-angle slopes and away from any terrain traps that could cause a deeper burial in case of an avalanche. 

    (12/6/2025) 

    Snowpit test showing failures on two buried weak layers in the upper snowpack.

    From: Bennett, Richard, Gus, and Ben

  • Wind Slabs

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

    The Summit Lake area looks like it was hit a little harder with winds yesterday than Turangain Pass, with wind speeds averaging 10 to 20 mph and gusts up to 35 mph on local weather stations. Today is expected to be less windy, but during this type of outflow wind event, it can be tricky to predict where and when the winds will pick up. To identify wind slabs you can look for active wind transport, feel for hollow snow along ridgelines and convex features, and jump on small test slopes. We expect wind slabs to be up to 1' deep, but a small wind slab could be enough to trigger a deeper weak layer and cause a much larger avalanche. 

  • Glide Cracks

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

    Glide avalanches have been releasing at an alarming rate so far this season, including along very popular travel corridors on the skier's side and motorized side of Turnagain Pass. The cold weather could induce a change in the glide avalanche activity, but no one really knows how this shift in weather patterns will impact glide avalanches. The best we can do is to minimize our time underneath glide cracks and stay vigilant for any new cracks forming on slopes above you. It is not uncommon for glide cracks to open up and then cause a natural avalanche within minutes to hours. 

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