A juicy storm will form fresh problems Tuesday night. Start small on Wednesday as you gather info. Call danger HIGH if you encounter more than 30 cm of new snow or signs of instability.
A crust / facet layer from November was 50 to 120 cm deep before the storm. 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.
Recent heavy snowfall means steep slopes on all aspects may hold reactive new storm slabs. This problem will be most concerning at higher elevations where snowfall and wind have been greatest.
A wet slab avalanche cycle to size 3 was observed in the Whistler area after around 90 mm of rain below 2000 m accompanied by heavy alpine snow. Monday morning, new size 1.5 wet loose releases were observed and explosives produced a size 2.5 wet slab. There's a good chance the largest releases involved the November crust as a failure plane.
Looking forward, more snowfall and mild temperatures are expected to perpetuate active conditions, with a shift toward dry slab activity.
20 to 30 cm of new snow should accumulate above 1500 m by Wednesday morning, bringing 24-hour totals to a possible 50 cm, increasing with elevation. This will overlie a rain-soaked snowpack to 2000 m and add to somewhat uncertain recent dry snow accumulations in higher alpine locations.
A crust with facets, formed in mid-November, was buried 50-120 cm deep, depending on the aspect, before the storm. Wednesday's cooling trend after all the rain bodes well for stabilizing this layer, but limited observations prevent us from gaining total confidence in it, particularly in alpine locations that may have escaped the bulk of the rain.
Tuesday Night
Cloudy with continuing snowfall bringing 20 to 30 cm of new snow, rain as high as 1500 m. 40 km/h southwest ridgetop wind. Treeline temperature reaching 0 °C with a brief 1700 m freezing level.
Wednesday
Mostly cloudy with isolated flurries and 2 to 3 cm of new snow. 30 km/h southwest ridgetop wind. Treeline temperature -5 °C. Freezing level 1000 m.
Thursday
Cloudy with continuing flurries bringing 10 to 25 cm of new snow, including overight amounts. 20 to 30 km/h south ridgetop wind. Treeline temperature -3 °C. Freezing level 1200 m.
Friday
A mix of sun and cloud with scattered flurries and a few cm of new snow. 10 km/h west ridgetop wind. Treeline temperature -7 °C. Freezing level 600 m.
More details can be found in the Mountain Weather Forecast.
