Persistent Slabs
- Hochgebirge
- Waldgrenze
- Unterhalb der Waldgrenze
- Wahrscheinlichkeit
- Unlikely
- Größe
- 1.5–2.5
Dense, 1-4 foot thick slabs of snow rest on top of layers of weak, sugary snow here. You're most likely to find a spot where you could trigger a slide involving these hard slabs in rocky upper elevation terrain where the wind has scoured the snowpack, creating thicker and thinner areas. Here, these weak layers are closer to the surface and impacting them with your weight remains an outside possibility.
Fortunately, avoiding this problem is fairly straightforward. You can dramatically reduce your risk of triggering a large avalanche today by avoiding rocky, wind-affected alpine terrain steeper than about 35 degrees. There is quite a bit of terrain that looks like this in the mountains along the eastern rim of this zone—from the White Clouds down south through the Boulders and into the Pioneers.
ADDITIONAL DISCUSSION: Small, thin wind slabs are building on a variety of weak surfaces that developed over the past several weeks. Though not large enough to bury you, these slabs can knock you off your feet and carry you downslope. Look for them near ridgelines in terrain exposed to the wind. Dune-shaped drifts and textures on the snow surface like waves and ripples are signs that the wind has been at work, as are fresh cornices along ridgelines. In areas sheltered from the wind, it will be possible to trigger small loose snow avalanches involving the new snow and the weaker facets underneath.