Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
2-3 foot hard slabs sit above weak, sugary snow near the ground where you could trigger a large avalanche with serious consequences. These avalanches will be possible in the middle elevations and most likely in the upper elevations on shaded slopes where buried layers have stayed colder and weaker (NW-N-E). Due to the variability of the low, early season snowpack and unpredictable nature of these types of avalanches, we recommend keeping a conservative approach to your backcountry travel plans by avoiding steep, complex terrain. All it takes is hitting that one sensitive spot to trigger the entire slope where avalanches will break deep and wide. Previous tracks are not a good indication of stability with this problem. Either stick with a conservative approach, or dig down frequently to look for those buried weak layers and assess the stability vs consequence yourself.
(12/14/2023)
This photo identifies the November drought layer. These weak layers can often be visible as a darker color and distinguishable as softer and less cohesive than the snow above.
Photo: Alex Drinkard