Bollettino valanghe

Summit Lake

Chugach National Forest Avalanche Center
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Pericolo valanghe

Sun
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
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In sintesi

Avalanche danger is on the rise as weather moves in today. Dangerous conditions will develop, with natural and human-triggered avalanches likely where strong easterly winds are loading slopes above 1000'. These wind slab avalanches will be around 1' deep and will be becoming larger and more sensitive through the day. They will be adding stress to multiple weak layers of snow buried 2 to 4' deep. This will increase the chances of seeing very large avalanches. Avalanche danger will spike tonight, and is expected to reach HIGH by sunrise tomorrow.

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SPECIAL ANNOUNCEMENTS:

Chugach National Forest Motorised Use:  Turnagain Pass and Snug Harbor are the only areas in the Chugach National Forest that received enough snow to open, all other areas remain closed. Low snow cover hazards exist at low elevations, such as open creeks and alders. We have limited information for these zones and recommend extra caution if riding on steeper slopes.

Problemi valanghivi

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2.5–3.5

    We've got another storm knocking on our door, and we're already seeing the winds ramp up ahead of the snow we're expecting tonight. Avalanche danger will be increasing through the day. It is likely a person will be able to trigger an avalanche a foot deep or deeper where the winds are building reactive slabs of snow (see problem 2 for more), and this fresh load is adding stress to the weak layers that produced the impressive avalanche cycle we saw last weekend. We will likely hit HIGH avalanche danger as precipitation intensity peaks late tonight.

    These deep persistent weak layers are difficult to assess. They will often give mixed results in stability tests, which can sometimes be misleading. The important thing to key into today is that we are on the front side of another big loading event, and we just saw a widespread avalanche cycle during our last big storm. That layer has gained some strength over the past week, and this storm is not going to be as big as what we saw last weekend. So although we're not expecting everything to fall apart the same way it did a week ago, we are expecting some natural avalanches, and human-triggered avalanches will become more and more likely as the storm develops.

    (1/18/2025)

    Predicted snow totals from 3 a.m. Saturday to 3 a.m. Sunday. Graphic courtesy of NWS Anchorage.

    Photo: Andrew Schauer

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1.5–2.5

    Natural and human-triggered avalanches will become more likely as the storm unfolds. The size and likelihood of these avalanches is increasing as of this morning, and that trend is expected to continue through the day. 

    Be aware of changing conditions and increasing danger today. The wind has been at work building slabs over the past two days, and the increasing likelihood of natural avalanches means we have to be paying attention to steep overhead terrain as well as the slopes we are traveling on. If you are trying to beat the storm it will be important to keep your head on a swivel. Pay attention to increasingly touchy conditions and look for more stable snow in areas protected from the wind.

    Cornices: We almost always see large cornices forming and failing during wind events like this. These cornices are a large enough hazard on their own, but they also have the potential to trigger a much larger avalanche on the deeper weak layers we are tracking (see problem 1 for more on that). This is one more reason to avoid lingering under steep slopes. It is also important to remember that cornices have a habit of breaking much further back than we expect, so give them plenty of space if you are traveling along ridgelines.

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