Bollettino valanghe

Summit Lake

Chugach National Forest Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Thu
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
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

Despite light amounts of new snow in the Summit Lake area, there will still be chances a person could trigger an avalanche on a layer of weak snow buried 1' deep or more in the upper elevations. This problem is more likely to be found in places that have been loaded by wind such as below ridgelines or in cross-loaded gullies. This weak layer is difficult to assess and can be completely avoided by sticking to slopes less than 30 degrees.

__________________________________

SPECIAL ANNOUNCEMENTS:

Come find us at the Seattle Ridge motorized parking lot on Saturday, March 22 for our annual Turnagain Pass Avalanche Awareness Day! We will be there with Alaska Mining and Diving Supply and the Alaska Avalanche School to chat about avalanches and current conditions and to hang out with the good people of the southcentral Alaska winter community. AMDS will have demo snowmachines, and we’ll be holding down the grill and the fire pit. Stop by anytime from noon until 4:00 p.m. Details Here.

Problemi valanghivi

  • Persistent Slabs

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

    Just a few inches of new snow has fallen in the Summit Lake area in the last 2 days accompanied by some moderate easterly ridgetop wind. This has added a little bit of stress to the buried surface hoar we are concerned with. This same weak layer is the culprit of many human-triggered avalanches in Turnagain Pass because there are more people out on the slopes and it has more snow on top of it causing it to fail with the additional weight of a person. See video to the right of an incident that occurred on Monday, March 17 on Seattle Ridge.

    The human-triggered avalanche on March 3rd on Tenderfoot and the skier-triggered collapse/whumpf on Saturday, March 15 on Colorado tell us this layer exists in Summit Lake and avalanches can occur. This will likely become a bigger problem once there is more snow added to the slab on top of the buried surface hoar. 

    There are some real challenges with this avalanche problem. This type of weak layer is inherently difficult to predict and can be triggered from some distance away and/or be triggered and slide on low angle terrain. Snowpits aren't relieable due to the spotty nature of the distribution. We have less information about this layer in Summit so snowpits are still useful to help us learn the distribution, but we can't rely on them for a decision to ride a slope or not. If you are getting into steeper terrain choose slopes that have not been loaded with wind (feels like firm snow over softer snow) and have less consequences below (rocks, trees, terrain traps).

    Cornices: Yesterday's snow and wind added stress to the cornices that are out there. If a cornice fall is triggered, it could trigger a slab avalanche below, so give these looming giants lots of space and watch for them from below.

    Glide Avalanches: Glide avalanches have released within the past week. Continue to avoid spending time underneath glide cracks whenever possible. 

Regioni coperte