Saturday's storm will increase both the likelihood and the consequences of triggering destructive avalanches on the South Coast. Travel in avalanche terrain is not recommended.
Up to 25 cm of new snow on Saturday will add to 30-60 cm of recent snow already sitting on a widespread weak layer that consists of a crust, with facets and/or surface hoar on top of it. Along with storm slabs formed of new snow, this deeper layer is expected to produce avalanches for longer than what is typical after a storm on the South Coast.
FRIDAY NIGHT: Cloudy with snowfall bringing 10-15 cm of new snow. Moderate south or southeast winds, becoming strong by morning.
SATURDAY: Cloudy with continuing snowfall bringing 15-20 cm of new snow, continuing overnight. Strong south winds. Alpine high temperatures around -4.
SUNDAY: Cloudy with continuing snowfall bringing 15-25 cm of new snow and 2-day snow totals to 50-70 cm, continuing but easing overnight. Moderate to strong south winds. Alpine high temperatures around -3 with freezing levels to 1000 metres.
MONDAY: Cloudy with isolated flurries and a trace of new snow. Light variable winds. Alpine high temperatures around -4.
Human triggered avalanches are expected to be very likely in many areas.
There have been numerous avalanches reported in the region everyday since Monday. These have been natural, human and explosives triggered storm slab avalanches failing on a prominent weak layer that is down 30-60 cm. A few recent MIN reports of some of these avalanches can be viewed here and here.
North Shore Rescue responded to a serious, but non-fatal avalanche incident on Tuesday evening in the backcountry 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. This avalanche also failed on the recently buried weak layer.
25-35 cm of new snow is expected to accumulate in the region by the end of the day on Saturday. This adds to 30-60 cm of recent snow that already sits on a widespread crust. This crust also has weak facets and surface hoar on top of it in many areas. This widespread weak layer will probably take more time to gain strength than what is considered typical for the South Coast region.
Click here to watch North Shore Rescue's January 22 snowpack discussion, which includes a great explanation of how the recently buried weak layer was formed.
