Boletín de aludes

Galena Summit & Eastern Mtns

Sawtooth Avalanche Center
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Peligro de aludes

Thu
Alta montaña
2 · Moderado
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil
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Desactualizado: este boletín caducó 2 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

Triggering large, destructive avalanches isn't out of the question. You can greatly reduce your risk by avoiding rocky and wind-affected slopes. You could trigger slides remotely—from flat terrain below, above, and to the sides of steep slopes. 

Problemas de aludes

  • Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1.5–2.5

    What and where is it: You are most likely to trigger a large, thick, 2-5 foot thick avalanche in terrain where the wind frequently blows, and the snowpack depth is variable. These wind-affected slopes are mostly found at upper elevations near ridgelines and prominent terrain features exposed to the wind. Triggering an avalanche is much less likely—but not out of the question—on steep slopes that appear to be completely sheltered from the wind. The slabs rest above a variety of weak layers (facets, surface hoar, crusts, and combinations) on most slopes.

    How can you recognize it: Watch for cornices, snow pillows, dunes, and ripples (photo). Feel for stiff snow under your feet or sled. These are signs the wind has been at work transporting snow. The slab above buried weak layers is not uniformly thick, and you may find a shallow spot where it is easier for you to trigger an avalanche. Rocks sticking out of the snowpack are clues that indicate a relatively shallow snowpack.

    How can you manage it: Before triggering an avalanche, you may or may not experience obvious signs of instability like snowpack cracking (photo) and collapsing or whumpfing. Avoid obvious wind-loaded slopes and terrain that is peppered with rocks sticking out of the snow. Persistent Slabs can release in surprising ways, break wider than expected, and release above or hundreds of feet away from where they are triggered. We can't assume tracks on a slope mean it is safe; several people could descend a slope before triggering an avalanche. Remotely triggering an avalanche from flat terrain near steep slopes is a possibility. Pay attention to how steep the terrain above you is. 

    Additional Discussion: You may be able to trigger wind slab avalanches in alpine terrain that formed near ridgelines and in cross-loaded areas on the sides of gullies. The size and chance of triggering these slides increase significantly as you climb into windier, alpine terrain at upper elevations. These avalanches could step down to the buried weak layers described above. Watch for snow pillows, dunes, and ripples, and feel for stiff snow under your feet or sled. These are signs the wind has been at work transporting snow.

    (1/5/2025)

    (1/4/2025) Snowmobilers remotely triggered this very large avalanche in the Salmon River headwaters. One rider was caught, fully buried, and successfully rescued. The crown is on a NE aspect near 9300'.

    Photo: Sawtooth Avalanche Center

Avalanche Discussion

It has been 5 days since our last big storm. Without new weight being added to the snowpack, buried weak layers are gradually adjusting to the load above, and signs of instability—like cracking or collapsing—may become less obvious. Ethan experienced this yesterday in the White Cloud Mountains, where he observed no cracking or collapsing, despite seeing numerous avalanches that had occurred during the post-Christmas and New Year storms. Others have reported similar experiences, noting limited signs of cracking or collapsing, with one observer describing the collapses as "muffled." These are encouraging signs that we're heading in the right direction. However, when we look back over the last week, we remain cautious about stepping into steep, consequential terrain. 

  • On Sunday, a group in the Frenchman Ck drainage reported remotely triggering an avalanche (2-3 feet thick, near 9000' on a NW-W aspect) while skiing in safe, gentle terrain nearby. The slide appeared to release in a wind-affected clearing a couple hundred feet below a lightly corniced, treed ridgeline. 
  • On Saturday:
    • Jan 4th,  snowmobilers in the Salmon River headwaters remotely-triggered a very large avalanche from several hundred feet below where the avalanche originated. The resulting slide caught, carried, and fully buried one of the riders. The rider deployed his airbag and was carried through trees. The other riders located the buried rider and extricated him from the debris in approximately 15 minutes. He was alert when he was evacuated to a local hospital for evaluation. The avalanche occurred on a NE aspect near 9500’ in elevation, was about 900 feet wide, and averaged 4 feet thick. 
    • Riders in Pole Creek triggered a small slide at a road cut (D1) and observed several other larger avalanches during their ride. They referred to the snowpack as "Very touchy" in shallow areas. 
  • On Friday, skiers noted a large avalanche below the Spring-Cherry Ridge that was likely triggered remotely from the nearby skin track. The avalanche occurred on a NW aspect near 9200'. 

Recent events—both natural and human-triggered—highlight a pattern: NW, N, NE, E, and SE-facing terrain above 8500' is the most concerning. Additionally, you are more likely to trigger an avalanche in areas where the snowpack is shallow. Shallow snowpacks exist in the eastern and southern mountains, OR in areas where the wind has redistributed snow, creating thinner spots where a skier or rider could more easily trigger an avalanche. Avalanches could be remotely triggered from these thinner areas, resulting in larger, thicker avalanches that could break above you. 

These conditions can feel frustrating at times, and the only way to truly minimize risk is to avoid avalanche terrain entirely. If you choose to enter avalanche terrain, you can stack the odds in your favor by avoiding areas with wind-affected snow and terrain peppered with rocks. You can further stack the odds in your favor by avoiding large avalanche paths and those with terrain traps (creeks, trees, or gullies where you would be carried or buried).

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