Soldier & Wood River Valley Mtns

Lawinenprobleme

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  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Very Likely

  Größe

  1.5–2.5

  If you were Santa deciding whether this season's snowpack was naughty or nice, you'd have an easy answer. Lurking beneath a charming (and powdery) exterior is a dangerous character flaw—weak October snow buried beneath a dense 2-3' slab. The facet layer is most prevalent on mid and upper elevation shady slopes (NW-N-NE-E facing).

  Our snowpack's true nature has been revealed a number of times this winter, including yesterday. Partial clearing skies revealed numerous large to very large avalanches that released as a result of Thursday's storm. Perhaps most notable is a huge avalanche on Galena Peak in the neighboring Galena Summit & Eastern Mtns zone (photo above/right) that would have destroyed your truck, the garage it was parked in, and the neighborhood you live in. Other large avalanches occurred in the Smokys (photo, photo) and Sawtooths (photo, photo). Observers on Titus Ridge watched a slope below them crack as they skied along the low angle ridge. Continued loading due to wind last night and snowfall today will keep our dangerous snowpack on the brink.

  While the snowpack deserves a few lumps of coal, you deserve some powder skiing and riding. Luckily for all of us that have been good boys and girls this year, there is incredible powder conditions to be enojyed in low angle terrain. Sticking to gentler slopes is the primary way to avoid the persistent slab, but also avoid being below steeper terrain since the possibility of remote triggering is real.

  

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  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Possible

  Größe

  1–2

  This extended period of stormy weather as delivered enough new snow and wind  to make triggering an avalanche a possibility even on slopes that lack the October weak layer. Yesterday, numerous storm slab avalanches were observed in the Sawtooths—most of these occurred in steep, wind affected terrain. The storm snow had a short chance to stabilize yesterday, but winds blew at moderate to strong speeds overnight and more snow is in the forecast today. 

  What this means is that we need to use caution on all steep slopes—even southerly-facing terrain where the persistent weak layer (Problem #1)  is absent. Storm slab avalanches are most likely in exposed, wind affected terrain at mid and upper elevations.