Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2
This zone has persistent weak layers buried 1-3 feet deep on most middle and upper elevation slopes. Recent observations from this zone indicate that these layers are trending towards "dormancy", and fewer signs of instability are being reported. But the occasional snowpack collapse and unstable snowpack test are good reminders that our weak layers of facets, depth hoar, and surface hoar still lurk in the snowpack ... #stillthere.
Today's forecasted 2-4 inches of new snow will not significantly impact these layers, and we remain in a holding pattern. You can reduce most of the risk of triggering a slide by understanding where avalanches remain possible and avoiding terrain with these characteristics:
- Wind-loaded terrain: Slopes where recent or past wind formed drifts and/or stiffened the snow surface.
- Steeper slopes: "Prime-time" avalanche terrain around 35-45 degrees in steepness.
- Southerly facing terrain: Crusts and facets 2-3 feet deep seem to be stabilizing more slowly on SW-S-SE aspects than the weak layers on shadier slopes.