Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Unlikely
- Size
- 1–2
Unlikely, but not impossible. That is the current situation. The persistent slab problem remains on slopes where December snow fell and formed a slab that buried weak, sugary snow left over from a cold and dry November. You are most likly to find this problem above 8500' on northwest through northeast aspects. These slabs could be 1-3 feet thick. Southern aspects did not harbor as much of this weak snow, particularly at lower elveations, and the strong diurnal temperatures over the last couple weeks helped the snowpack adjust to the current load. Within the Grays River zone, snow depths vary widely between the Snake River Range, Salt River Range and Wyoming Range. As a rule, the Salt River Range has the deepest snowpack. While it is unlikely that you will impact the weak layer in a way to trigger an avalanche, there are still areas that carry high consequence from even a small avalanche. Continue to trench your sled track or probe with a ski pole to confirm or deny the presence of weak, sugary snow below you.
Watch out for steep, rocky, unsupported slopes. Remember that you might find the trigger even after multiple people have ridden the same slope. Size up the slope before you ride it and consider what would happen if you triggered a small slab. Would it drag you through shallow rocks or into a terrain trap? Steer clear.
(12/15/2023)
Natural avalanche 10,500' SE aspect likely occured on 12/10 after loading event when winds increased.
Photo: Alex Drinkard