Avalanche forecast

Summit Lake

Chugach National Forest Avalanche Center
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Avalanche danger

Tue
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 9 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

Human-triggered avalanches on lingering buried weak layers 1 to 3' deep above 2500' are the main concern today. In addition, wind transported snow along exposed ridgetops and areas experiencing outflow winds could cause natural or human-triggered avalanches up to 1' deep. Finally, large glide avalanches have been releasing throughout the region and continue to be a concerning hazard that is best to avoid. 

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 warm and wet weather last week didn't do any favors for the skiing and riding conditions, creating an icy crust up to about 2600'. However, now that the snowpack has refrozen, the silver lining is that the wet weather added some strength to the snowpack. So we an not as concerned about buried weak layers at treeline elevations and below.

    Above 2500', we are still concerned about several weak layers of buried surface hoar that range from 1 to 3' deep in the snowpack and have the potential to cause large human-triggered avalanches. Buried surface hoar is notorious for giving no signs of instability (no red flags) and remaining dangerous for a long time, which makes it very difficult to assess and manage. One public observation from this weekend shows that these weak layers are still concerning in the Summit Lake area. To avoid the potential for being involved with one of these avalanches, you can always stick to simple, low angle terrain and avoid travelling above terrain traps like gullies, trees, or cliffs. 

     

    (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

    Ouflow winds like we are currently experiencing often have a significant impact in the Summit Lake area, even when the nearby weather stations are not necessarily picking up strong winds. Currently, local weather stations are showing averages of 10 to 15 mph from the Northeast with gusts up to 35 mph. Natural or human-triggered wind slabs up to 1' deep are possible and could cause larger avalanches on buried weak layers. These typically form along ridgelines and convex rolls where wind transported snow accumulates. To identify areas harboring wind slabs, you can look for active wind loading, shooting cracks, and hollow sounding pillows of new snow.

  • Glide Cracks

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

    Glide avalanches continue to release across the forecast area on a wide variety of aspects and elevations. These large and destructive avalanches are very unpredictable, and the best practice is to avoid them as much as possible. A glide crack can form and cause an avalanche within minutes to hours, so it is important to be aware of the slopes above you and look for recently formed glide cracks. Several large glide avalanches have released in the past week that did not have an obvious crack on the surface the prior day. 

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