Persistent Slabs
N
NE
E
SE
S
SW
W
NW
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
You can trigger avalanches below ridgelines and near convex rollovers. This is particularly true for slopes that face northeast through east to southeast. Winds drifted snow into firm slabs on these aspects. Look for and avoid rounded pillows of hollow-feeling snow. You will probably not see any warning signs before you trigger an avalanche.
You may be able to trigger loose avalanches made up of weak faceted grains in steep north-facing areas. You can identify these spots because the snowpack is cohesionless from top to bottom.