Wind slabs may be found on a variety of aspects and will likely remain sensitive to human triggers Friday.
The persistent weak layer may still be possible to trigger in areas that have not already avalanched. Be especially cautious in these places.
Wind slabs may remain triggerable by humans. Be aware of the potential for wind loading in atypical terrain features on southerly aspects due to recent northerly winds.
A widespread weak layer consisting of a crust, with facets and/or surface hoar overtop is now down about 80-150 cm. This layer may still produce large avalanches in areas that have not already avalanched.
Thursday night: Mainly cloudy with a few flurries, up to 5 cm, moderate westerly ridgetop wind, treeline temperature -5, freezing level 700 m.
Friday: Mix of sun and cloud, light northwest ridgetop wind, treeline high -1, freezing level 1000 m.
Saturday: Light flurries, up to 5 cm, strong northwest ridgetop wind, treeline high -1, freezing level 1000 m.
Sunday: Mix of sun and cloud, light westerly ridgetop wind, treeline high -1, freezing level 500 m.
Human triggered storm slab avalanches remain likely in wind loaded areas at upper elevations. The recently buried persistent weak layer may be possible to trigger in areas that have not already avalanched.
It was a busy week for avalanche activity in the South Coast mountains, with natural and/or human triggered avalanches reported every day between Monday, January 25, and Monday, February 1, culminating in a widespread natural avalanche cycle, with avalanches up to size 3, on Monday night. Most of these avalanches failed on the persistent weak layer. This was likely the peak of the avalanche activity associated with this layer.
North Shore Rescue responded to a serious, but non-fatal avalanche incident last Tuesday evening near Cypress Mountain Resort. One person was involved and was partially buried. The avalanche was a size 2 storm slab on a west aspect at approximately 1100 m and failed on the persistent weak layer.
80-150 cm of snow sits over a widespread persistent weak layer. This weak layer consists of a crust that also has weak facets and surface hoar on top of it in many areas. This layer has been taking more time to gain strength than what is considered typical for the South Coast region.
Click here to watch North Shore Rescue's January 29 snowpack discussion, which illustrates this concerning snowpack structure.
