Deep Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2–3
On northwesterly to northeasterly aspects above 9,000 feet, deep slabs lie upon faceted snow and hard crusts. A single rider or skier could impact this weak layer and trigger a large, destructive avalanche with slab depths up to five feet. Large triggers, such as snowmobiles, are more likely to cause failure of this weak layer. As the day progresses blowing snow will rapidly load avalanche starting zones and increase the potential for deep slab avalanche occurrences.