Persistent Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Possible
- Dimensione
- 2–3
Multiple layers of weak snow can be found at various depths in the upper 3 feet of our snowpack. The sensitivity and likelihood for avalanche activity on these layers have been fluctuating throughout the season. On 4/9, moderate stress from new snow and solar heating led to an increase in avalanche activity, including some remote triggers. After a brief period of adjustment, these persistent weak layers are receiving another gradual increase in stress with new snow loads. The evolution of this problem should be monitored closely as we receive additional snowfall today and into next week. Eventually, we may reach a point where activity becomes likely again. For today, avalanches 1-2+ feet deep will be possible in specific areas. Likely trigger points will include areas with a thinner snowpack and/or deep wind-drifted snow on the surface. Snow accumulation over the next 12 hours is expected to be on the light side, but if you find new snow deeper than 6 inches, expect the increasing stress to elevate this hazard.
There will be a lot of users on the Pass this week for Hill Climb, with people likely putting tracks in and high-marking all over. Just because a slope already has a bunch of ski tracks or high marks on it doesn’t make it safe. Use safe travel protocols that include spotting your partners, riding slopes one at a time, while avoiding grouping up at the bottom of the runout zones.
Deep persistent slab: Buried weak snow near the ground has been unreactive for quite a while now. There is currently a low probability of triggering a layer this deep, but as we continue into our spring thaw, this layer may become stressed enough to produce some large avalanches. Keep this on your radar as conditions change toward the end of our season.
(4/9/2026)
D2 avalanche triggered remotely while skinning. Failed on old persistent weak layer after party had already skinned through the area.
Wortmans, The Island, ~2800', North