Persistent Slabs
- Hochgebirge
- Waldgrenze
- Unterhalb der Waldgrenze
- Wahrscheinlichkeit
- Unlikely
- Größe
- 1.5–3
Our field team has been monitoring two persistent weak layers buried in the snowpack on sheltered, shaded slopes. The primary layer of concern is buried surface hoar 50 cm below the surface. Additionally, a layer of faceted snow has been consistently located about 70 cm below the snow surface. Although there has not yet been any avalanche activity on either of these layers, we are consistently observing their presence, and receiving stability test results that align with an avalanche being possible.
This persistent slab problem is a low likelihood, high consequence situation. If a slide were to occur on these layers, it could easily be fatal. These problems are notoriously hard to predict and provide minimal feedback to warn of their potential to slide. Due to this, exercising extra caution on terrain where the PWLs could be present is highly recommended. Unsupported and larger slopes on these sheltered north aspects are where this problem would have higher consequence. Thin areas of the snow such as near large rocks and cliff bands are where you could be more likely to trigger these weak layers.
