Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2–3
Weak facets, depth hoar, or collapsible crusts exist on the northern half of the compass and on some sunnier aspects at high elevations. Slabs on top of these weak layers average 1.5 to 3 feet thick in wind-sheltered terrain. Slabs are thicker and harder in wind-drifted terrain and can step down through older slabs to the ground. This problem has become stubborn to triggers, often requiring a thin spot on the slope, such as near buried rocks, trees, or where slabs thin from wind effects. Avalanches can break widely across multiple terrain features and be remotely triggered from flat terrain near or below steep slopes without warning signs. The problem can be avoided on slope angles consistently less than about 30 degrees.
A couple of persistent slab avalanches that were remotely triggered in the upper Cement Creek area on Friday.