Avalanche forecast

Soldier & Wood River Valley Mtns

Sawtooth Avalanche Center
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Avalanche danger

Thu
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Conditions are dangerous. You are likely to trigger avalanches big enough to bury people and possibly vehicles. At upper elevations, you could trigger thinner avalanches in terrain affected by the wind. 

Heavy snowfall and wind will cause the danger to spike tonight and Thursday. If you're out after dark, expect very dangerous avalanche conditions to develop. AVALANCHE WARNINGS may be issued.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–3

    You're likely to trigger large avalanches, and some of them could be big enough to destroy houses. Dozens of large natural and human-triggered avalanches released last week, and the snowpack is still adjusting to the weight of the early February storms.

    Avalanche activity has been focused on the northern half of the compass (W-NW-N-NE-E) in middle and upper elevation terrain, failing on faceted snow buried about 2-4 feet deep. On sunnier aspects, crust + facet combinations exist deep in the snowpack and are also suspect.These avalanches can release in surprising ways. You can trigger them from flat or low-angle terrain long distances away from steep slopes, and they can break far above you. You may or may not experience snowpack collapsing or other obvious signs of instability before triggering an avalanche.

    If your primary goal is to not get caught in an avalanche, staying off of and out from below steep slopes is the move today.

    (2/6/2024) The Sun Valley Ski Patrol ski-triggered this large avalanche Tuesday morning in the Cold Springs Chutes in the Sunrise Expansion Area. This area has not yet been opened to the public. It failed on a NE aspect near 8000'. The slide was 2-4 ft tall, 100 ft wide, and broke branches during its 900 ft vertical run. The debris piled up 4-7 feet deep against trees. Photo: Sun Valley Ski Patrol

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Yesterday, Ethan observed a recent natural avalanche in wind-loaded upper elevation terrain in the Soldier Mtns (view Observation). The fresh drifts overlie weak snow (crust + facets, facets, surface hoar, or slick crusts) on many slopes, making the slabs especially easy to trigger in places. 

    Wind slabs and drifts could also produce thicker avalanches involving the February storm snow. While we have not observed many avalanches failing on this weak layer buried 1-2 feet deep, the resulting slide would be larger than you might expect. 

    Drifts, ripples, and dunes are clues the wind has been at work. If you see cracks shooting out in front of your skis or boards or feel the snow stiffen beneath you, the prudent move is to stick to gentler terrain. The wind slab avalanches could carry you where you don't want to go, and they have the potential to trigger the Persistent Slab avalanches described above. 

Avalanche Discussion

The snowpack, and snow stability, vary significantly in this zone. Evidence (avalanche activity, snowpack observations, weather patterns, etc) indicates that triggering big, Persistent Slab avalanches is less likely in the Soldier Mtns and the west side of the Smoky Mtns (west of Dollarhide Summit). You’ll find exactly the opposite scenario in the mountains surrounding HWY 75; there, triggering scary Persistent Slab avalanches remains far more likely. Yesterday, a longtime local experienced "one of craziest collapses I have ever experienced! Very loud and rumbled/ propogated away from me and through the forest for what seemed like 3-5 seconds after. Heart to throat!" He wisely avoided all avalanche terrain. Determining where the transition from “sketchy” to “not as bad” occurs is an inexact science at best - recognize that drainages near the crest of the Smoky Mtns could fall on either, or both, sides of the stability spectrum.

Heavy snowfall and wind will cause the danger to spike tonight and Thursday. If you're out after dark, expect very dangerous avalanche conditions to develop. AVALANCHE WARNINGS may be issued.

Regions covered