Avalanche Forecast
Regions: Brandywine, Garibaldi, Homathko, Powell River, Sea To Sky, Spearhead, Tantalus.
Measure your exposure to avalanche terrain carefully as you check out the storm's aftermath. Take a big step back if you find signs of instability like shooting cracks or recent avalanches.
Confidence
Moderate
Avalanche Summary
Several small natural and human caused avalanches have been reported since the parade of storms began. These include wind slabs and storm slabs to size 2. Some of these have stepped down to layers 40 to 60 cm deep (and counting) in the snowpack.
At lower elevations, small wet snow avalanches have been reported. This potential should diminish with cooling on Sunday.
Snowpack Summary
An uncertain 5 - 15 cm (or more?) of new snow should accumulate overnight Saturday, bringing storm totals to roughly 40 - 60 cm, all of it heavily wind affected. This overlies problematic faceted snow, or surface hoar in sheltered terrain. In exposed terrain, it more likely overlies a sun crust (an excellent bed surface for avalanches) or previously wind-affected snow.
A weak layer that was buried at the end of January is now 50 to 90 cm deep in the snowpack. This may present as a crust on sunny slopes, sugary facets in most places, and surface hoar in sheltered spots. Saturday's storm load will test this layer and human triggering will continue to be a serious concern for Sunday.
The snowpack below is strong.
Weather Summary
Saturday night
Cloudy with wet flurries bringing 5 - 15 cm of new snow, greatest in the alpine. 20 to 50 km/h southwest ridgetop wind, easing. Freezing level 1500 m - 1800 m.
Sunday
Partly cloudy with flurries beginning late afternoon. 10 to 30 km/h south ridgetop wind. Freezing level 1500 m.
Monday
Partly cloudy with scattered flurries easing after 10 to 20 cm overnight accumulation, greatest in the alpine. 20 to 50 km/h south ridgetop wind. Freezing level 1300 m - 1500 m.
Tuesday
Cloudy with scattered flurries bringing 5 - 10 cm of new snow, including overnight amounts. 20 - 60 km/h. Freezing level 1200 m - 1400 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Approach lee and cross-loaded slopes with caution.
- Storm slabs in motion may step down to deeply buried weak layers and result in very large avalanches.
- Even brief periods of direct sun could produce natural avalanches.
Avalanche Problems
Storm Slabs
Storm snow has buried a variety of problematic surfaces, including crust, faceted snow, and surface hoar. Expect to find deeper, more reactive slabs perched on steep leeward slopes.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 1 - 2
Persistent Slabs
Weak layers that formed during the January drought may become active again with increased load and warm temperatures. Smaller storm slabs may step down to these layers and become large avalanches.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1.5 - 3
Loose Wet
Triggers in steep terrain may be capable of producing wet snow releases before a surface crust forms and free water drains away. Slopes in direct sunlight are the most concerning.
Aspects: South, South West, West.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 2