Persistent Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Unlikely
- Dimensione
- 1.5–2.5
Weak layers of snow are buried 2-4 feet deep on middle and upper-elevation shady slopes. You may see plenty of slopes that have tracks on the surface. Remember that it is the thin spots in the snowpack where your weight might reach down to impact this weak layer. This avalanche problem type is most commonly found on isolated slopes with the following characteristics:
- Very steep: slopes steeper than about 35 degrees. Convex and unsupported slopes are also most suspect.
- Rocky: slopes with variable snow cover due to the roughness of the terrain. Think rocks beneath the surface perforating the strong slab above.
- Wind-affected: slopes where winds produce variable snow depths. Scouring produces thin spots while deposits further stress the slab.
(1/28/2025) Wind affected snow and cornices on the Ramshorn ridge. It's the variable snow depth, steepness, and rocky ground that causes concerns for triggering a persistent slab avalanche. Due to the uncertainty of the thickness of the slab on this slope, riding it fully depends on your tolerance to consequential risk taking. Great riding was found in wind and sun sheltered areas nearby.