Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 3
It's been two weeks since the last significant storm and avalanche cycle. Our buried persistent weak layers (PWLs) are now more stubborn to trigger as they gain strength. While you likely won't see any red flags like cracking and collapsing, the snowpack structure is still poor. MODERATE danger with a PWL is a tricky place to be: possible avalanches are that are more than likely to kill you.
On northerly aspects near and above treeline, thick hard slabs—2 to 4 feet deep—rest on top of these persistent weak layers. This is a highly unpredictable setup, and committing to steep slopes with this structure is a gamble. If triggered, avalanches could step down and take out the entire season’s snowpack.
Thin, rocky areas, steep convex rollovers, and slab margins remain likely trigger points. When the payoff for riding steep terrain is minimal, it’s hard to justify the risk. Our approach continues to be simple: avoid steep slopes in this terrain altogether.
Eric and I shot this video yesterday where we found the weak layer to be gaining strength, but not yet stable.
