The next wave of the storm puts us back in snowpack building mode. Carefully measure your exposure to avalanche terrain and be ready back off where you encounter signs of instability.
A crust / facet layer from mid-November is buried 60 to 100 cm deep. Continued loading and copious water in the snowpack keeps the chances of triggering it elevated.
10 - 30 cm of new snow will build new storm slabs (wind slabs where accumulations are less) on Tuesday. Snowfall rates, temperatures, and danger should peak toward end-of-day.
Wet loose avalanches will become increasingly likely if the snow surface becomes moist or wet, especially where new snow sees rain.
Observations have been limited during the storm, but two size 3 avalanches ran in the Hurley and Upper Lillooet Provincial Park areas on Sunday. Whether they failed on the November crust is uncertain, but this layer is likely to have been the involved in some of the larger releases during the storm.
Looking forward, a switch to dry snow will promote the formation of a new storm slab problem, with snowfall rates, temperatures, and danger expected to peak at end of day Tuesday.
10 - 30 cm of new snow should accumulate by end of day Tuesday, covering a rain-soaked snowpack to about 2100 m and adding to somewhat uncertain dry snow accumulations above this elevation. Reactive new storm slab and/or wind slab problems should be the result.
A crust with facets, formed in mid-November, was buried 50 to 100 cm before the storm. At least two wet slabs are believed to have failed at this layer in the storm and continuing snowfall prevents us from gaining much confidence in it, even as temperatures cool.
Monday Night
Cloudy with flurries bringing 5 to 10 cm of new snow. 40 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level bottoming out at 1100 m.
Tuesday
Cloudy with increasing snowfall bringing 5 to 20 cm of new snow. 20 - 30 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1300 m.
Wednesday
A mix of sun and cloud with isolated flurries after 20 to 30 cm of overnight snow. 20 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1300 m.
Thursday
A mix of sun and cloud with isolated flurries bringing 5 to 10 cm of new snow, including overnight amounts. 20 km/h south ridgetop wind. Treeline temperature -3 °C. Freezing level rising from 1000 to 1500 m.
More details can be found in the Mountain Weather Forecast.
