Its snowing! Storm slabs are forming at higher elevations and not expected to bond well to the old snow surface.
Confidence
Low - Intensity of incoming weather systems is uncertain
Weather Forecast
SUNDAY NIGHT: Flurries, up to 20 cm accumulating overnight, moderate south west wind, freezing level 1000 mMONDAY: Flurries, 5 -15 cm snow expected, moderate south-southwest wind, freezing level 1200mTUESDAY: Snow, accumulation up to 45cm, moderate southwest wind with strong gusts, freezing level 1100mWEDNESDAY: Continued snow, accumulating 20-30 cm, moderate southwest wind with strong gusts, freezing level below 1000m
Avalanche Summary
Prior to the new snow, reverse-loading winds have created small (size 1) wind slabs in lee features which are reactive to skier traffic around the Whistler area. On steep, sun exposed features in the alpine, solar warming has produced small (size 1) loose snow avalanches over the past few days. Avalanche activity will depend on new snow bonding with the old surface layer.
Snowpack Summary
Snowfall beginning Sunday has added up to 30cm around the region. The new snow has buried a weak surface layer sitting over 20-30 cm of low density faceted snow and the new snow is initially not expected to bond well with the older snow.Prior to this storm, alpine snowpack depths varied around 150-200 cm, with an early November crust at bottom of the snowpack (down 100-120cm). This crust appears to be breaking down at higher elevations and has been unreactive to snowpack tests. Snowpack depths disappear quickly with decreasing elevations (starting around 1800m).
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.