Gather information about the depth, slab properties, and bonding of the new snow as you gain elevation on Saturday and be mindful of overhead hazards. Be ready to take a step back if the sun comes out in the afternoon.
Overnight snowfall and elevated, shifting winds will be forming a new storm slab problem to manage on Saturday. This problem will likely increase with elevation and exposure to wind. Be especially mindful of areas where wind slab and cornice distribution overlap.
Friday night: Cloudy with flurries bringing 10-20 cm of new snow. Light to moderate southwest winds, easing into the morning.
Saturday: Cloudy with isolated flurries, clearing overnight. Light northeast winds. Alpine high temperatures around -10.
Sunday: Increasing cloud. Light west winds, becoming moderate or strong at ridgetop. Alpine high temperatures around -11.
Monday: Mainly cloudy. Light west winds, becoming moderate at ridgetop. Alpine high temperatures around -8.
Thursday's reports showed a few small (size 1) wind slabs triggered with ski cutting and skier traffic on steeper rolls and ridgetop features.
Reports from Wednesday included observations of numerous storm slabs triggering with ski cutting, primarily highlighting the north of the region. At 10-20 cm deep, these releases matched the depth of our most recent snowfall, but were also observed entraining snow to the depth of the crust buried up to 30 cm deeper.
With continuous stormy weather over the past week, there have been a handful of very large (size 3-4) avalanches breaking on deeply buried weak layers on slopes above 2000 m. Although the likelihood is low, large wind slab avalanches or large cornice fall may have the potential to step down to these layers.
30-50 cm of snow from the early part of the week now overlies older wind-affected snow at high elevations, with about half this amount instead overlying a widespread melt-freeze or rain crust to a variable upper extent of 1700-2400 metres in elevation. The recent snow has shown variable reactivity, with reports showing a mix of soft wind slabs around treeline, sluffing of low density snow in steep terrain, and poor bonding with the buried crust where it exists.
The mid and lower snowpack are generally well settled and strong. Although isolated, there are two deeper weak layers that may persist in some areas. A weak layer of surface hoar buried 90 to 170 cm deep may be found across the north of the region while a facet/crust layer from November may be found near the ground in shallower snowpack areas.
