Observe the depth of new snow to determine the scale of the storm slab hazard in your area on Monday, but be conscious of very different conditions in overhead terrain. Significantly more new snow exists in the alpine and in areas closest to the coast.
New snow will continue to add to storm slabs at higher elevations on Monday. Expect the depth and reactivity of slabs to greatly increase with elevation and exposure to wind.
Wet loose avalanche conditions should ease as temperatures drop on Monday, but surface snow will remain unstable at elevations that continue to see rain accumulating instead of new snow. Be conscious of this problem around steep slopes at lower elevations.
Sunday night: Cloudy with continuing snowfall bringing 5-20 cm of new snow to treeline and alpine, increasing with elevation and proximity to the coast. Light rain below about 1700 metres. Strong southwest winds. Freezing level peaking at 2000 metres and descending again through the morning.
Monday: Cloudy with continuing snowfall bringing about 10-25 cm of new snow, increasing with elevation and proximity to the coast. Light to moderate south winds. Alpine high temperatures around -3 with freezing levels to 1400 metres.
Tuesday: Cloudy with increasing snowfall bringing 10-30 cm of new snow, increasing with elevation and proximity to the coast. Moderate to strong south winds. Alpine high temperatures around -5 with freezing levels to 1200 metres.
Wednesday: Cloudy with isolated flurries. Light southeast winds. Alpine high temperatures around -5 with freezing levels to 1200 metres.
Observations from the weekend storm are still limited, but initial reports from Saturday described touchy new slabs reacting easily to ski cuts on steeper features up to treeline on all aspects. Alpine elevations were largely avoided with visibility obscured. Fracture depths of up to 30 cm were observed.
Looking forward, continuing snowfall is expected to maintain similar conditions on Monday, with new snow and associated avalanche hazards increasing with elevation.
5-20 cm of new snow, increasing with elevation, is expected to fall in the region by the end of the day Monday. This will cover rain-wetted surfaces below about 1700 metres and add to roughly 15-70 cm of snow from the weekend storm, again increasing with elevation and with proximity to the coast.
The storm buried recent wind slabs and wind-affected surfaces in exposed areas at all elevations and soft, low density snow in sheltered areas. It adds to just over a meter of storm snow that has fallen in the last week.
A pair of weak surface hoar layers from mid and late December existed about 70 to 160 cm below the surface in advance of the storm. These layers were given a good loading test at most elevations by the storm, but still warrant caution around steep, sheltered slopes and shallow rocky areas.
A layer of sugary faceted grains and hard melt-freeze crust exists near the base of the snowpack in inland parts of the region, such as the Spearhead Range. This layer also received a good loading test by the storm, but continues to warrant avoidance of shallow rocky start zones in the alpine and upper treeline.
