Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
The westerly wind will begin moving snow as soon as it hits the ground. Wind slabs will build overnight and during the day. Remember that wind slabs can be many times deeper than the snow that fell out of the sky. Below ridges and highpoints are places where wind blown snow often accumulates. Slabs can also form as wind moves across a slope and fills in depressions and gully features. Wind slabs can be tricky to judge because some lee features will have minimal wind loading while other features seem to collect a lot more blowing snow. Deeper wind deposits can lead to larger avalanches. Cracking in the slab or recent avalanches are good indicators of unstable snow.
The distribution diagram above is where I expect wind slabs to be found. However, it is your job to always be on the look out for changing conditions in the field. Remember that wind slabs can also form in areas of dead or sparse trees below treeline.
Archive Photo:
Cracking in new wind slab. This cracking was initiated by the skier stepping out onto a slab.