Persistent Slabs
N
NE
E
SE
S
SW
W
NW
- Alpine
- Treeline
- Below treeline
- Likelihood
- Unlikely
- Size
- 2–3
Triggering an avalanche that breaks in weak snow layers several feet deep becomes more difficult after a solid snowpack refreeze. High, northerly-facing slopes where wind-drifted areas span adjacent terrain features could produce a wider-breaking avalanche. A large trigger like a falling cornice or deeply-trenching snowmobile may have better odds at impacting deeper weak layers than a human-trigger. If you see evidence of drifting like lens-shaped snow pillows, fresh cornice growth, or blowing snow along ridgelines, use caution above terrain traps or cliff bands where a smaller avalanche could magnify the consequences of getting caught.