|Persistent Weak Layers:
Certain weak layers tend to stabilize quickly after a storm
while other kinds of weak layers take much longer to stabilize.
The three most notorious, persistent weak layer include: faceted
snow, depth hoar and surface hoar. As you can imagine, persistent
weak layers cause most avalanche accidents because the avalanche
danger can linger several days after a storm, just waiting for
The presence of a persistent weak layer, alone, doesn’t
necessarily mean danger. But If a buried, persistent weak layer
also produces a high quality shear and is also weak on your
strength tests, you should definitely avoid avalanche terrain
where those conditions exist.