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Lawinenprobleme

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  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Possible

  Größe

  2

  The main problem continues to be the poor snowpack structure that remains throughout the entire Wasatch Range, this make up of strong snow over weak faceted snow. The problem primarily exists on shady slopes at the mid and upper elevations, where a strong slab of snow can release and fail in the weak faceted snow below. Snowpit results, significantly fewer reports of cracking and collapse and lack of avalanche activity show that the likelihood of triggering an avalanche is decreasing, however, it is still not zero.

  We get it, the best coverage and riding seems to be in steep north-facing terrain. While it could be the best riding, this terrain is exactly where the avalanche danger is heightened. As soon as you decide to ride steep northerly facing terrain at the mid and upper elevations, you are rolling the dice as triggering a slab avalanche 1-3’ deep remains possible. This is just the type of problem I don’t want to test the boundaries of, my strategy will be to continue avoiding this steep terrain until the weak layer of faceted snow is buried so deeply that it no longer is a problem, or melts in the spring - whichever comes first.

  Another thing to think about: While we haven’t had a large snow load on the weak faceted snow in over a week, wind drifted snow can act as a load to the snowpack - even when it’s not snowing. Over the past 6 days, we have had high winds and increased wind loading. The ESE winds will have loaded NW facing terrain and anywhere recently wind drifted snow sits atop the weak faceted snow will have an increased load.

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  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Possible

  Größe

  2

  Over the last few days the winds have been cranking, and last night the winds changed from Northwesterly to Easterly changing the aspect that will have signs of obvious wind loading. The combination of these sustained days of wind and few new inches will have allowed for new wind drifts to form. While there wasn’t a ton of new snow to move around, with such high winds any snow that was available to be transported, will be transported at the mid and upper elevations. Last night the winds switched to Easterly which will have loaded unusual terrain features compared to the Northwesterly winds we have been experiencing. Sustained high winds can deposit snow around terrain features on almost any aspect, this is known as cross-loading. For this reason, I would expect to find sensitive slabs of wind drifted snow at all mid and upper elevation slopes, especially along with terrain features such as ridgelines, sub ridges, and gullies.

  The winds have backed off a bit this morning, but even with a few elevated gusts throughout the day, these slabs will become more firm and cohesive. This can allow you to travel out farther onto the slope before it breaks, and can fail larger and wider than expected. Triggering an avalanche that initially fails in the wind-drifted snow will likely break down more deeply into the weak faceted snow below.

  Today continue to look for slopes with any signs of wind drifted snow, such as cracking, hollow noises, and pillow-shaped snow, and avoiding those slopes.