Wind Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Likely
- Dimensione
- 1–2
In areas receiving high winds with loose snow on the surface wind slabs are expected to form on leeward slopes. These are most common near ridgelines and prominent terrain features. Keep an eye out for deeper pillows of wind transported snow and look for shooting cracks or small avalanches on test slopes as a warning sign for unstable wind slabs. Typical wind slabs are 6-12" deep but can be deeper in gulley features or depressions.
The new snow that fell yesterday buried a layer of surface hoar that was widespread across the forecast area. In locations where the surface hoar was buried upright, wind slabs could be much more reactive to the weight of a person. Remote triggering is also possible, which is when a person initiates an avalanche from an adjacent low angle slope.
Persistent Slabs: There was a remote triggered avalanche in Triangle Bowl on Seattle Ridge on Wednesday that we believe was caused by a layer of buried surface hoar underneath an older wind slab. We have not observed this setup in other locations in Turnagain Pass but it is possible that an older layer of buried surface hoar could cause larger human triggered avalanches 1-2' deep. You can jump on test slopes or dig a snowpit to check whether this structure exists in the area you are traveling.
