Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1.5–2.5
Triggering a large, dangerous avalanche that breaks in deeper weak snow layers is slowly becoming more difficult, but is not impossible. You can get into trouble if you find the shallow area of the slope where it is easier to impact weaker snow in the middle or bottom of the snowpack. Likely trigger spots exists near shallowly buried rocks, on steep rollovers, and below ridges and cliffs.
Westerly winds continue to drift snow above treeline, and form thicker slabs on leeward slopes. Use caution on steeper slopes if the snow surface transitions from soft to stiff, or in places with a rounded or wave-like appearance. An avalanche on a freshly drifted slope has the best potential to step down to deeper weak layers. Safer riding options exists on low-angled, wind-sheltered slopes without steep overhead hazard.