Bollettino valanghe

Sawtooth & Western Smoky Mtns

Sawtooth Avalanche Center
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Pericolo valanghe

Tue
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
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Non aggiornato — questo bollettino è scaduto 6 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Dangerous avalanche conditions exist. Triggering a large avalanche is likely on many steep slopes. Skiers and riders should continue to choose low-angle terrain that isn't threatened by steeper slopes above. There have been many human-triggered avalanches in the past week. Most of these were triggered remotely—from below, above, and to the sides of steeper slopes.

Problemi valanghivi

  • Persistent Slabs

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

    The storm early last week added more load to our well-established persistent weak layer that is now buried around 2-3 feet deep in this zone. The highest concentration of observed natural avalanches occurred in the drainages near Smiley Creek (example) and in the far Western Smokys, but slides also occurred in the Sawtooths. On Wednesday and Friday of last week, riders remotely-triggered avalanches in the Western Smokys (photo, photo). Chris was in the northern Sawtooths on Saturday, where he found a 2.5' thick, dense slab atop a layer of sugary facets that was showing little signs of improvement. With the weak layer in this zone more deeply buried, it may be somewhat more difficult to trigger a slide than in other portions of the forecast area. But if you do trigger an avalanche, it's likely to be a big one that will be difficult to survive.

    Yesterday, an experienced observer south of this zone remotely triggered a large avalanche that failed on a steeper slope adjacent to where he was skiing. He reported hearing wood breaking as the avalanche descended the slope. I was in the Gladiator Creek drainage yesterday, investigating a large natural avalanche (photo at right) that appeared to have released within the past two days. You can watch a video describing what I found and why it is important here: Gladiator Creek Avalanche. The snowpack is a bit thinner in both of these areas, but not fundamentally different.

    There are two key factors that point to this instability being especially long-lasting and unpredictable: 1) the buried weak layer is especially bad, and 2) this weak layer has been very slowly loaded over the past three weeks.  Recent natural and human-triggered avalanches confirm this fact. We urge backcountry skiers and riders to continue to choose low angle slopes and to pay extra attention to the terrain they're "connected" to. Remotely triggering an avalanche from below, above, and to the sides of steep slopes remains a very real possibility.

Avalanche Discussion

I understand your frustration when you check the forecast every morning and the avalanche danger remains elevated. I would love to be able to tell you that everything is safer today. But, my job isn't to tell you what you want to hear, it is to accurately describe the conditions in the backcountry. The snowpack varies across our area, but the basics are the same everywhere. Weak, faceted snow is buried beneath a 1-3' thick slab.

Even as the days pass since the storm last week we continue to see obvious signs of instability relating to this weak snow. Each day, observers report widespread cracking and collapsing of the snowpack, even on heavily traveled skin tracks. More importantly, observations of both natural and human-triggered avalanches continue to roll in. Our snowpack is speaking to us plainly and cleary. Our job as riders and skiers is to listen to what is being said. 

We deal with dangerous avalanche conditions by operating with wide safety margins. Stay alert to the terrain that you are traveling through and that you are exposed to from above. Today is not significantly different than yesterday and we need to continue to make conservative decisions in the backcountry in order to ensure our safe return home at the end of the day. 

Have a look at the Weekend Update that I published on Friday to catch up on more of what happened this past week. 

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