Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Unlikely
- Size
- 1–2
Although limited, our data for the zone shows that this problem has trended toward unlikely. You can still find buried weak layers 1-1.5 feet down throughout the zone on all aspects. The most suspect place you'd still trigger a slide is in exposed wind-loaded terrain, and weak layers can be buried even deeper here, too. Also, the warm up on Saturday could play a role in triggering an avalanche. Areas immediately adjacent to the Cascade Crest will get rain Friday night into Saturday morning all the way to upper elevations, and areas further east will see a good amount of sunshine. Should liquid water reach these buried weak layers, it could reinvigorate instability. Cornice fall could become an issue as things warm up, and a big trigger such as this might be just what it takes to let loose a deadly avalanche.
This problem is tricky to manage in the backcountry. If you plan to travel near a neighboring forecast zone, consider reading that forecast as well to equip your toolbelt with more information. Either way, ease into terrain slowly and be thoughtful about the complexity and exposure of slopes you plan to ski or ride. You're unlikely to get clear feedback from the snowpack before triggering a large slide in consequential terrain.
(3/1/2026)
Snow machine triggered large (D2) persistent slab and self extricated on 2/28. Darland Mt. NE aspect, 6700 ft.
HS- AMu-R2-D2-O @ NE, 6700' Photo: Northwest Avalanche Center