Bollettino valanghe

Seward and Lost Lake

Chugach National Forest Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Sun
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
Open full map
Non aggiornato — questo bollettino è scaduto last year. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

This is the second day we are issuing a Special Avalanche Bulletin due to the potential for a human to trigger a large avalanche on a weak layer 1 to 2' deep. This layer has been responsible for multiple recent human triggered avalanches. With such dangerous conditions we recommend choosing lower angle terrain that is not near steep overhead slopes.  

__________________________________

SPECIAL ANNOUNCEMENTS:

We are sorry to report a fatal avalanche accident that occurred outside of Girdwood on the afternoon of March 4, 2025. Three people were caught and killed in an avalanche in the west fork of the Twentymile River. Ongoing recovery efforts are being coordinated by the Alaska State Troopers. We extend our deepest condolences to the friends and families of all parties involved. We have posted a preliminary accident report on our website. 

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    2–3

    Recent Avalanches: There were reports of multiple remote triggered avalanches in Lost Lake yesterday. There were also several large avalanches reported on mountains around Seward and seen at a distance closer to Lost Lake. These are the same scary avalanches we have been seeing in Turnagain Pass from the Valentine’s Day buried surface hoar layer.

    We are still very concerned that someone could trigger a large avalanche on a layer of surface hoar buried 1 to 3’ deep. There are three reasons why we feel extra cautious and are making conservative travel decisions:

    1. There have been multiple human triggered avalanches between 1,500 and 3,000’ and some above 3,000’ that we suspect failed on this layer.  
    2. Some of these avalanches have been remotely triggered meaning you can be traveling on low angle slopes and trigger a large avalanche on a slope above you or on an adjacent slope. Surface hoar is also known to trigger avalanches on lower angle slopes. 
    3. Spooky distribution and test results: In Turnagain Pass this layer is widespread at mid elevations but harder to find at upper elevations. We expect the same dangerous snowpack in Seward and Lost Lake. You may not find it on the slope you are on then travel another 100’ and trigger an avalanche. Snow tests have produced stable and very unstable results. This type of weak layer is known to produce stable results and give the false sense that the slope you are on is safe then produce a large avalanche.

    The big picture based on the evidence is that we have a buried weak layer that has been found guilty of triggering large avalanches on multiple aspects and elevations. So what do we do about it? The safest option is to avoid traveling in or below avalanche terrain. Make conservative decisions today which means not trying to outsmart the problem so we can get home safe and sound. 

    Other hazards to look out for are cornices falling from ridgelines which could trigger an avalanche above you. Loose snow avalanches may begin to avalanche naturally on steep sunny slopes if the sun comes out. A large glide crack opened recently in Turnagain Pass which is telling us that more may follow suit. Spend as little time under these as possible or avoid them altogether as they can open at any time creating large glide avalanches. 

    (3/6/2025)

    Zoomed in photo of the avalanche activity on Resurrection South, you can see the slabs in this photo.

    Photo: Mik Dalpes

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    We saw strong winds transporting snow on the mountains close to Seward yesterday into fresh wind slabs. Seward and Lost Lake may have received more than 12” new snow from Wednesday’s storm, possibly forming wind slabs may be up to 3’ deep that may be easy to trigger. We are unsure if these winds reached Lost Lake and Snug Harbor, something to be wary of. Look out for shooting cracks and snow that becomes stiff underneath you. These are clues you are traveling on a wind slab. The worst case scenario would be triggering a wind slab that steps down to a weak layer creating a much larger avalanche.

    (3/7/2025)

    Howling winds actively loading slopes on Mt Marathon. 

    Photo: Sarah Schuh

Regioni coperte