Persistent Slabs
N
NE
E
SE
S
SW
W
NW
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
Recent snowfall and westerly winds increase your chances of triggering an avalanche where you encounter 8 inches or more of cohesive snow on slopes steeper than around 35 degrees. The most dangerous slopes face the north half of the compass, where very weak snow lurks under the new snow. New snow will be more cohesive in wind-drifted areas, especially at upper elevations below ridgelines.
Cracking in the snow surface, collapsing or “whumfing,” and easily triggered loose avalanches are all signs of instability and indicate you should retreat to lower-angled slopes. Avalanche conditions are the most dangerous we’ve seen in a month.