Persistent Slabs
N
NE
E
SE
S
SW
W
NW
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2–3
You could trigger a large and dangerous avalanche on steep slopes where you find a slab of newer snow on top of weak older snow. The most dangerous slopes are at upper elevations, where deeper and more connected slabs exist. Many recent avalanches have failed in areas of wind-drifted snow adjacent to rock outcroppings.
Avoid trigger points, such as shallowly buried rocks or small trees, convexities, and the edges of slopes where the slab is thinnest. If you find a shallow spot and trigger a slide, it could break wider and deeper than expected. You could also trigger an avalanche from a distance. You can find safer travel on slopes less than about 35 degrees in steepness.