Bollettino valanghe

Summit Lake

Chugach National Forest Avalanche Center
Vedi sulla mappa

Pericolo valanghe

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

In sintesi

There is a small chance that a person can trigger a large avalanche on a weak layer of snow buried around a foot deep. This layer has been an issue in Turnagain Pass and Seward, and is slowly starting to show signs for concern in the Summit Lake area. If you are planning on traveling in steep terrain, avoid traveling on slopes with higher consequences. This includes large slopes, and anything with terrain traps like gullies, cliffs or trees. You can avoid the problem entirely by staying away from steep terrain.

__________________________________

SPECIAL ANNOUNCEMENT

Avalanche Accident:  We are deeply saddened to report a fatal avalanche accident on Saturday, on the back side of Seattle Ridge in Turnagain Pass. Our preliminary report can be found here. We are working on collecting more information and will publish a full accident report as soon as we have all of the information from the event.

Sean Sullivan, Cory Davis, and Travis Temple will be hosting a free avalanche awareness and rescue training event in memory of Tucker Challans on Saturday, March 29, at Alaska West Air in Nikiski. See the flyer in the media gallery below for more information.

Problemi valanghivi

  • Persistent Slabs

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

    Recent Avalanches: There was a fatal avalanche accident on the back side of Seattle Ridge in Warmup Bowl on Saturday in which the rider was caught and buried, and did not survive. There have not been any recent avalanches in the Summit Lake area, but skiers did report collapsing and shooting cracks on Raven Ridge and John Mtn over the weekend.

    The weak layer of buried surface hoar that has been a concern throughout our forecast areas has recently been showing signs that it is getting closer to its breaking point in the Summit Lake zone. John and Daniel visited Raven Ridge yesterday to investigate reports of large collapses, and they found a very well preserved and reactive layer of surface hoar buried about a foot deep (more details here). This had produced shooting cracks and collapsing, two clear signs of unstable snow. 

    As of now, it seems like there aren't very many slopes where there is enough snow sitting on top of that intact surface hoar layer to be a major concern in Summit Lake. However, we do know that problem exists, and we also know that it can be very challenging to assess. This type of problem can make avalanches even when there are no warning signs, or when there are multiple sets of tracks on a slope. Keep this high uncertainty in mind and reduce your risk exposure by avoiding terrain with higher consequences if you were to trigger an avalanche. This includes slopes with terrain traps like gullies, cliffs, or trees in the runout zone, or large connected slopes that could produce very large avalanches. 

  • Wind Slabs

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

    Yesterday's east winds have already started to back down, and should remain light today. However, they were blowing strong enough to move snow for the past 24 hours and some of those most recent wind slabs may remain reactive today. These will be around a foot deep, and are most likely to be found in upper elevations on steep slopes below ridgelines, convex rolls, and steep gullies. You may see signs like shooting cracks or collapsing, or it may be more subtle clues like stiffer snow sitting above softer snow. These relatively smaller avalanches will be big enough to be a concern on their own, but also have the potential to step down to a much larger avalanche described in Problem 1 above.

    Loose Snow Avalanches: Skiers yesterday reported widespread rollerball activity on steeper slopes, indicating the snow on the surface is becoming warm in the heat of the day. Be on the lookout for loose snow avalanches if the sun pokes through the clouds even for a short while. These often release near trees or rocks, or below cornices. They can be particularly dangerous on longer slopes where they can entrain more snow, or if they run into terrain traps like gullies or cliffs.

    Glide Avalanches: We're continuing to see glide avalanche activity across the advisory area. There is currently a very large glide crack on Mt. Marathon, which may release at any time, or may slowly creep open and never release. These avalanches are very large and unpredictable. The best way to manage this problem is to avoid spending time under open glide cracks.

     

Regioni coperte