Persistent Slabs
- Alta montaña
- Límite del bosque
- Bajo el límite del bosque
- Probabilidad
- Possible
- Tamaño
- 3
Once initiated, avalanches can break into weak layers of snow buried in the mid portion of our snowpack, resulting in a slide that gets quickly out of hand.
No dramatic changes in this camp. Yes the snowpack is adjusting to last weeks big storm and the lack of avalanche activity suggests a slow turn towards stability... good news. But, I can't ignore the inherently sketchy structure formed by two weeks of dry, bitter cold weather during mid November, which created a layer of very weak, sugary facets on the snow surface. And I can't cast aside the fact that those layers are preserved underneath several storms and buried in the mid portion of our snowpack. So yes, I'm thinking not only about the snow I'm riding in, but also the snow I'm riding on. Here's where the rubber hits the road and what makes things tricky right now... any avalanche that fails near our new problem child, the persistent weak layer or (PWL), is gonna break deep and wide and it's gonna be dangerous.
Unless you take your shovel out, dig down and investigate a bit, you can easily get lulled into a false sense of snow stability because the snowpack has gained a substantial amount of buoyancy and will feel strong and solid underneath us. But remember- hard, dense snow resting on weak, sugary snow can give us a false sense of snow stability, allowing us to get out further onto a slope before it fails and brings the entire roof down on top of us.
Obvious signs of unstable snow include cracking, collapsing, and whoomping noises as well as natures freebie... natural avalanches!
Micheal J's pit profile confirms our continued concern wit our snowpack setup. MJ's got a great trip report from yesterday while he was in the Hoyt environs.