Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 2
Persistent weak layers of loose, sugary, faceted snow are present on many aspects and elevations. On slopes facing NW-N-E-SE, slabs 1'-3' deep exist on top of these weak layers. While recent warm temperatures and time have helped the snowpack gain some strength, deep and dangerous, human-triggered avalanches remain possible in these areas. The danger increases with elevation and human triggered avalanches become more likely above treeline, particularly on slopes with recent deposits of wind drifted snow.
The photos below illustrate classically poor snowpack structure with a clearly defined fist to 4 finger hard slab on top of weak, sugary, facets. In other words - strong snow over weak snow. Stability tests indicate a stubbornness to release but this only makes them harder to predict. It's like provoking someone with a violent temper - you don't know when they are going to explode. As long as this snow structure remains in place, I won't be provoking any steep northerly facing slope.