A warm storm with mixed precipitation is approaching.
Avalanche hazard is expected to increase throughout the day Wednesday.
Avoid avalanche terrain during periods of heavy snowfall.
Stormy weather will continue to create widespread reactive slabs. Storm slabs may step down to deeper buried weak layers, creating larger avalanches.
As the surface snow becomes saturated with rain, wet loose avalanches may occur, and in turn could trigger larger storm slabs. It’s unclear whether precipitation will fall as snow or switch over to rain at treeline.
A very natural large avalanche (size 2,5 or 3) occurred near Overseer Mountain this weekend from a leeward alpine slope, prone to loading with southerly winds.
Several explosive and human-triggered avalanches were reported in the Whistler/Blackcomb area over the last few days. These storm slabs ranged from size 1 to 2.5, with some stepping down to deeper buried layers like the Mid-November crust up to 1 m deep.
15 to 25 cm of new snow can be found above 1800 m, which was redistributed by southerly winds in alpine and upper treeline terrain. This new snow will add to previous storm slabs that have formed over the last few days, which currently overlie older layers such as surface hoar, facets, and crusts.
A new breakable, melt-freeze crust is found at the surface at mid-elevation. The mid-November hard crust currently sits 60 to 120 cm deep with facets above and below. Some recent storm slabs have stepped down to this layer.
The snowpack height rapidly diminishes below 1100 m.
Tuesday Night
Cloudy. Snow starting early evening. 50 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level 1500 m.
Wednesday
Cloudy. 30 to 50 mm of precipitation as snow or rain at treeline. 50 km/h southwest ridgetop wind. Treeline temperature 0°C. Freezing level rising to 1800 m.
Thursday
Mostly cloudy. 40 km/h northwest ridgetop wind. Treeline temperature -3 °C. Freezing level 1500 m.
Friday
Cloudy. 5 to 10 cm of snow. 30 km/h west ridgetop wind. Treeline temperature -4 °C. Freezing level 1200 m.
More details can be found in the Mountain Weather Forecast.
