Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1
There is a lot going on in this photo but yesterdays close call goes to show that these pockety, persistent slab avalanches are in fact a player and reactive to our additional weight (via A. Richards).
Consistent winds blowing from the west have pressed stiff, hard slabs together that feel solid under our ride and sit above a sugary layer of faceted snow that formed over the recent stretch of high pressure. Above treeline on steep and wind-loaded slopes, specifically with with an easterly component, these slabs living on faceted snow are reacting to our additional weight well after they formed -- This is why we have transitioned our wind-drifted snow problem to a persistent weak layer. The chances of triggering this avalanche problem decreasing, but if you're getting after it on sustained, steep terrain in the alpine, remember even a small slide in consequential terrain could turn nasty as it strains you through trees, rocks, or over cliffs.
Fortunately, we can avoid this problem by seeking wind sheltered terrain out of the alpine where you'll be greeted with less avalanche danger and protected, cold, recycled powder.