Over 100 cm of new snow has fallen this week, and it needs time to settle and bond.
Stormy conditions on Wednesday will continue to build slabs that could be surprisingly deep and reactive.
A November crust/facet layer exists deep in the snowpack. Conditions have lent well to cleaning out and stabilizing the problem, but it may still be possible to trigger, particularly in thin-to-thick areas in the alpine.
Snowfall, wind, and warming on Wednesday will continue build storm slabs that will likely be larger and more reactive in northerly, wind-loaded terrain.
On Sunday, a snow cat in the Whistler area triggered a size 2 persistent slab on a northwest aspect in the alpine.
On Monday, skiers in the Whistler area triggered size 1 storm slabs in lee terrain features in alpine and treeline terrain. Observations were limited by stormy conditions.
Looking forward to Wednesday, fresh, reactive storm slabs are expected to build with snowfall, wind, and warming.
Up to 20 cm of new snow by end of day Wednesday overlies over 100 cm of settled storm snow from the past week. Strong southerly winds have left a variety of surfaces - wind slabs and loaded pockets in lee features, scoured rock in open terrain, and storm slabs and softer snow in sheltered areas.
This week's storm snow buries a melt-freeze crust that exists at 2200 m and below. The depth of this crust is highly variable due to extensive recent wind transport.
A crust with facets, formed in mid-November, is buried an estimated 80 to 150 cm deep. With limited observations, especially in the alpine (which did not have the same mid-pack crust development), we're not ready to rule out this layer of concern quite yet.
Tuesday Night
Partly cloudy. 1 cm of snow. 10 km/h southeast ridgetop wind. Treeline temperature -5 °C.
Wednesday
Cloudy. 15 to 20 cm of snow. 20 to 50 km/h southeast ridgetop wind. Treeline temperature -4 °C.
Thursday
Mix of sun and clouds. 1 cm of snow. 15 km/h southeast ridgetop wind. Treeline temperature -4 °C.
Friday
Mostly cloudy. 1 to 4 cm of snow. 10 km/h southwest ridgetop wind. Treeline temperature -7 °C.
More details can be found in the Mountain Weather Forecast.
