Soldier & Wood River Valley Mtns

Lawinenprobleme

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Likely

  Größe

  1.5–3

  You could trigger 1.5-4 foot thick slabs, especially where wind formed drifts or stiffened the snow surface. Triggering an avalanche is less likely—but not out of the question—on steep slopes that are completely sheltered from the wind. The slabs rest above a variety of weak layers (facets, surface hoar, and crusts + facet combinations). The widespread nature of these weak layers means avalanches are likely on many aspects. 

  Snowpack cracking and collapsing or whumpfing are clear signs of unstable conditions. However, a lack of these obvious warning signs doesn't mean you're in the clear. Approach the mountains with the assumption that weak layers exist on many slopes. 

  Avoiding steep, wind-loaded slopes can significantly reduce your chances of triggering an avalanche. Persistent Slabs can release in surprising ways, break wider than expected, and release above or hundreds of feet away from where they are triggered. It's possible to remotely trigger an avalanche from flat terrain near steep slopes. Manage your group by riding or crossing steep slopes one at a time, and avoid areas where terrain features like gullies, cliffs, or dense trees could increase the consequences of a slide.

  Additional Discussion: You may be able to trigger wind slab avalanches 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.