Persistent Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Possible
- Dimensione
- 1–2
Triggering an avalanche on old November snow near the base of the snowpack is possible if you find yourself in the wrong spot. You're most likely to encounter this "wrong spot" on steep, north-facing terrain above 7000'. Test pits continue to show inconsistent results. Some locations show no propagation on this weak layer and some do. Yesterday, I dug a pit on a steep, rocky slope facing NE. The video to the right shows what you could find there. This is the worst case scenario. The best way to manage this problem is to avoid this terrain. Unforuntately, this persistent weak layer is not disappearing anytime soon. The weight of a snowmachine is more likely to impact these buried weak layers than the weight of a person.
ADDITIONAL DISCUSSION
A few inches of snow fell earlier this week with SW winds. Yesterday, we observed some small amounts of wind loading on NW through E aspects above 7000'. This new snow was failing easily in wind-loaded terrain. Although very shallow, sensitive wind slabs could pack a punch if you find yourself in steep, consequential terrain. Another reason to have a healthy dose of skepticism of steep, north-facing terrain at upper elevation.