Soldier & Wood River Valley Mtns

Lawinenprobleme

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  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Likely

  Größe

  1–2

  Yesterday, Ben remotely triggered a large avalanche from a safe ridgeline in the Boulders. The avalanche was about 250' wide and released on weak snow near the ground (video at right/below). Additionally, a 1-2' thick natural wind slab avalanche was reported in the Soldier Mountains. Triggering a similar avalanche is likely today. This problem is at its worst in upper elevation terrain and along the northern border of this zone. Given the intensity of the recent wind (video at right/below), anticipate these slabs on any open slope, including the mouths of main drainages and roadways that typically funnel wind.

  While dangerous on their own, these fresh slabs have the potential to release on the persistent weak layers described below. Cornices will be sensitive and may calve off to release slabs on the slopes below. Drifts, dunes, rippled snow surfaces, and chalky snow pillows are clues that the wind has been at work.

   

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  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Possible

  Größe

  1.5–3

  Expect to find dangerous slabs in areas affected by the wind. You could also encounter thin, sensitive slabs in areas sheltered from the wind where storm totals approach 10" or more. These slides will break widely on a weak snow interface, including slick facets, crusts + facets, and surface hoar.  

  Triggering a very large, destructive 3+ foot thick avalanche on weak layers near the middle and base of the snowpack is a real possibility. The odds that these deeper weak layers wake up will only increase as the storm intensifies this evening and tomorrow. 

  Anticipate touchy conditions as you climb into windier terrain. Persistent Slab 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. Snowpack cracking and collapsing are obvious clues that the slab + weak layer combination you've encountered is unstable.