Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
If triggered, expect to initiate lower weaker persistent layers creating a large avalanche.
Natural avalanche activity is still being observed and human triggering of avalanches remains likely. Make conservative terrain choices by sticking to low angle terrain well away from steeper slopes.
If triggered, expect to initiate lower weaker persistent layers creating a large avalanche.
This avalanche problem is associated with a weak facet and crust layer buried at the end of January approximately 70cm down in sheltered areas. This includes a crust layer formed in early March below the recent storm snow which is prominent on solar aspects.
Well developed facets and depth hoar at the bottom of the snow pack can produce large avalanches. Several big avalanches released during and immediately after the March 7th storm. Be suspicious of any slopes that have not released naturally.
A field team observed 3 new size 2 natural avalanches in the icefields area on Saturday. They appeared to be a mix of the wind slab, persistent slab, and deep persistent slab problems, which occurred in steep rocky terrain in the alpine and at tree line.
They also noted very large whoomphs while traveling on skis, indicating the snowpack is still primed for triggering large avalanches.
Wind slabs exist in lee features throughout tree line and alpine areas. The 70-90 cm from earlier in March has settled into a supportive slab. Below this, the snowpack is complicated and reactive, having multiple crusts and facet layers including the deep persistent basal layer.
Sunday
Cloudy with scattered flurries.
Accumulation: 4 cm.
Alpine temperature: High -5 °C.
Ridge wind southwest: 20-40 km/h.
Monday
Mainly cloudy with scattered flurries.
Accumulation: 4 cm.
Alpine temperature: Low -7 °C, High -4 °C.
Ridge wind west: 20 km/h gusting to 60 km/h.