Avalanche forecast

Summit Lake

Chugach National Forest Avalanche Center
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Avalanche danger

Tue
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
No rating
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Highlights

Strong wind is forecast to continue today from the east. It could be easy for a human to trigger a wind slab avalanche above 2,500'. There's a chance a larger avalanche could occur failing on weak layers buried in the snowpack. The most likely place for this to happen is where upper elevation slopes are being actively wind loaded. Steer clear of these problems by avoiding steep slopes in the upper elevations. 

Avalanche problems

  • Loose Wet

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

    Without any new precipitation in the last 24 hours we aren't sure how likely it is for a human to trigger a wet avalanche in the Summit area. Roller balls are a sign wet loose avalanches could happen. If you find yourself in wet snow you can jump on a small test slope to see if the snow wants to move. If it does, be cautious not to get tangled up in one of these slides on a larger slope. Especially if the slope runs into trees, rocks, or gullies.

    DOT camera image of the Summit Lake area (mile 45) yesterday just after 4pm. It looks damp, but no precipitation was recorded yesterday.

  • Wind Slabs

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

    The precipitation didn't show up to the Summit area like we hoped it would yesterday (0" recorded at the Summit Creek SNOTEL) , but the wind sure did, and continues to blow today especially above 2,500'. New snow fell on Saturday (6 to 7") above the rain/snow line and has been available for the wind to move into fresh wind slabs that could be 1' deep or more. The safest choice today is to avoid the upper elevation steep slopes.

    If you are heading up high today watch for blowing snow and avoid areas where it is landing. These areas can be found below ridgelines, on convex rolls, and in cross loaded gullies. After several days of blowing snow, these wind slabs could be fresh and touchy or they could be old and a bit stubborn. A shooting crack indicates unstable snow.

    Here are the totals from Thursday through Monday morning with estimated snowfall amounts above 2500':

    • Girdwood: 2.99" water (12-24" snow)
    • Portage: 10.48" water (30-50" snow)
    • Turnagain Pass: 3.8" water (18-30" snow)
    • Summit Lake: 0.7" water (6-8" snow) No new in the last 24
    • Seward/Lost Lake: 2.6" water (12-24" snow) 

    Image from the Windy.com forecast platform with a point in the upper elevations of Summit Pass. The yellow and pink colors are indicating forecast 25 to 40 mph windspeeds today at 5,000'.

  • Persistent Slabs

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

    Visibility has been poor so we haven't been able to assess what avalanches have occurred in the last few days during this storm. What we know is that the snow that fell on Saturday (6 to 7") and the constant wind has added stress to the buried weak layers in the Summit snowpack. We don't know if it has been enough to tip the scales and cause any of those weak layers to fail above 2,500' where this problem exists. If an avalanche is triggered on one of these layers it could be very large. We recommend giving the snowpack time to adjust and avoiding steep wind loaded upper elevation slopes for now.

     

    (12/19/2024)

    Photo taken a few days ago of the Summit Lake area looking south as this series of storms approached.

    Photo: Daniel Krueger

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