Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1.5–2.5
The persistent slab problem exists in locations where snow has been preserved since November forming a weak layer that is now buried 1.5-3 feet deep below firm, cohesive slabs. In general, this weak, sugary snow structure exists above 8500’ and will be most reactive on shaded aspects (NW-N-NE). As this problem trends more stubborn adjusting to the current load, the possibility still exists to trigger an avalanche. The best way to manage this problem is to choose terrain away from steep, rocky, and complex slopes where you are most likely to encounter those thin and sensitive areas of the snowpack. Riding across one of those thin, sensitive areas could collapse the weak layer and trigger a large/destructive avalanche.
Significant variability in the snowpack exists throughout the zone between the Wyoming, Salt, and Snake River Ranges. Submit an observation to help us tune into your local area and improve our forecast ability.
(12/21/2023)
Here is a good example of the terrain where triggering a persistent slab is most likely. These avanches occured during out last storm cycle.
Photo: Alex Drinkard