West Slopes North

Lawinenprobleme

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  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Likely

  Größe

  1–2

  You can trigger storm slab avalanches in the snow that's falling Sunday night. Avalanches may fail within this new layer only a few inches deep, or near the bottom of the overnight snow, which could be closer to a foot, or slabs could fail within any number of storm instabilities in the upper portion of the storm layer that began Thursday night and totals 2.5 inches of water and almost 3 feet of snow.

  These storm slab avalanches could come in any variety of flavors: Light, fluffy slabs that recently fell could release with a human trigger, or maybe even naturally. Wind slabs will exist in some areas, and may be deeper. You can identify textured or pillowlike, thicker-feeling deposits.  It'll be easier to trigger an avalanche on a wind-loaded slope. Sluffs, or dry loose avalanches, could occur naturally or with a human trigger. 

  With all of these concerns- and the following Persistent Slab problem - the advice is the same: Avoid steep slopes. If you were just looking at these newer, shallower storm instabilities, you might be able to step out in steep terrain if you know how to manage it, but given deeper underlying layers of concern, that isn't a wise option right now. 

  

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Possible

  Größe

  2–2.5

  There's no point beating around the bush- we've got a dangerous Persistent Slab avalanche problem out there, friends. 

  • You could trigger an avalanche that could fail in weak, faceted snow or on slick snow beneath the new snow layer, what we've now dubbed the "January Drought Layer" or JDL. Several avalanches have failed on this layer already: human-triggered (like the one on the Elbow on Sunday) and natural. Crowns are generally 30" or deeper! 
  • Avalanches could also fail on the 1/10 crust, which is about 8 inches beneath the new/old interface, resulting in an even larger, unsurvivable avalanche.
  • Avalanches could surprise you by propagating wide or traveling far back into lower-angle terrain above the start zone. They also might be triggered or break lower in the path than expected. 
  • Depending on where you are in the zone, other underlying weak layers may also come into play. Alternatively, some spots may not have as much of a problem. 
  • We don't have enough information to limit aspects now, but steep south-facing slopes are the least likely to have this problem. 
  • When the new storm layer starts getting deeper at just over 4000ft, these weaknesses are probably more preserved, and enough new slab weight exists communicate a failure. 
  • The extent of these weak layers is very inconsistent, so digging a pit in one spot or skiing one slope doesn't mean it's safe a few feet away. 

  To manage this problem, avoid all steep slopes. If you see natural avalanches, experience whumphs, or remotely trigger avalanches, avoid all avalanche terrain including where an avalanche runs and stops.