If the new snowfall surpasses 30 cm, the danger level in the alpine and at treeline is deemed considerable.
Exercise caution at higher elevations; anticipate building storm slabs.
Storm slabs will begin to form late in the day and will be found in the upper treeline and alpine elevations. The touchiest slabs may be in lee terrain features.
As precipitation switches from snowfall to rainfall, expect the upper snowpack to become unconsolidated.
On Friday near whistler, explosive avalanche control operations working the the alpine trigger two size 2 avalanches and numerous size 1 avalanches. They all failed within the storm snow, just above a buried hard melt-freeze crust from December 21st .
If you do head into the backcountry please consider submitting observations and/or photos on the Mountain Information Network.
During Saturday night a period of clear and cold created widespread SH at both treeline and alpine elevations, the incoming storm is likely to bury this and become a layer of concern. We expect the past storm snow to have effectively bonded to the old surfaces but in large open connected alpine terrain is 10 to 20 cm deep and may be a concern
Below treeline, you'll likely find dirt, shallow, heavy, moist or wet snow.
The mid and lower snowpack is made up of a series of crusts and rounded grains and is well consolidated.
Overall, the snow depth tapers rapidly with elevation and remains shallow creating challenging travel conditions and hiding early season hazards just below the snow surface.
Sunday Night
Partly cloudy. A trace of new snow expected. Treeline temperature around -1 °C. Freezing level rising to 1000 m. Strong south ridgetop wind.
Monday
Cloudy. Heavy snow and rain expected to begin in the pm 60 to 80 mm. Freezing level rising to 1200-1500 m. Treeline temperature around 1 °C. strong gusting extreme, south east ridgetop wind.
Tuesday
Cloudy. Heavy snow and rain that is expected to cease in the am 20-40 mm. Freezing level 1200-1500 m. Treeline temperature around 1 °C. Strong easing to moderate , south east ridgetop wind.
Wednesday
Cloudy. Snow and rain that is expected to begin in the pm 5 to 10 mm. Freezing level 1500-1900 m. Treeline temperature around 3 °C. Moderate gusting strong, south east ridgetop wind.
More details can be found in the Mountain Weather Forecast.
