Persistent Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Likely
- Dimensione
- 1.5–2.5
Weak snow from November has a slab of December snow around 2-3+ feet thick. Each of our past storms has caused a clear pattern of natural and human-triggered persistent slab avalanches on the north half of the compass at middle and upper elevations. If you venture to these slopes, it's safe to bet that this layer sits beneath your boards or sled. Right now, we benefit from evidence being easy to find in the form of natural and remotely triggered avalanche activity, and this layer is reactive in snowpits across the zone and easy to find. This problem is best managed through a conservative slope angle and steering clear of slopes highlighted above. Persistent slabs can break broader than you expect and can be triggered from flat slopes connected to steeper terrain above or next to you. You can reduce your risk by traveling on slopes where the problem isn't highlighted above or by traveling on smaller terrain features without terrain traps. Avoiding areas of wind-loaded snow will also decrease your odds of triggering an avalanche. Some slopes below about 10,500' on southerly-facing terrain currently lack the problematic structure and may offer lower-risk options.
(12/12/2023)
A separate large avalanche in Horseshoe Bowl on a NE aspect around 9,700 feet.
Photo: Gabrielle Antonioli