Avalanche Forecast
Issued: Dec 11th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
zryan,
Avalanche Canada
You're most likely to encounter avalanche problems at higher elevations near ridges and peaks that are away from the coast where the snow was deep, dry, and will take more time to settle and gain strength.
Watch for rapid changes to the upper snowpack if the wind picks up or the sun comes out!
Summary
Confidence
Moderate
Avalanche Summary
During the storm on Saturday, several small (size 1) natural and human-triggered storm slab avalanches were reported in the North Shore mountains. These avalanches occurred at treeline and below treeline on a variety of aspects.
Looking forward to Monday, we expect storm slab activity to drop off with cooling temperatures. The avalanche problem will likely be more confined to wind-loaded areas at upper elevations. Be cautious around these denser and deeper slabs as they may remain sensitive to human triggering.
Keep sharing your observations via the MIN; it helps strengthen our information gathering.
Snowpack Summary
Upper snowpack: Last week's storm snow totals around 50 to 70 cm. This storm arrived warm and mixed with rain near the coast (e.g. North Shore Mountains). This new snow is sitting on a sun crust on steep, solar aspects and feathery surface hoar crystals in isolated sheltered and shaded areas. Mid-pack: softer, weaker layers of less cohesive snow around 80 - 100 cm down should be gaining strength as they squish. Lower-pack: a thick melt-freeze crust and increasing strength.
At 1000 m the snowpack depth is around 150 cm. In many areas, below treeline elevations are still below the threshold for avalanches.
Weather Summary
Sunday night
Cloudy with clear periods. Alpine temperatures drop to a low of -3 °C. Ridge wind light to 15 km/h from the northeast. Freezing level 100 meters.
Monday
A mix of sun and cloud. Alpine temperatures reach a high of -2 °C. Ridge wind light to 20 km/h from the northeast. Freezing level rising to 400 meters.
TuesdayCloudy with sunny periods and isolated flurries, trace new snow accumulation. Alpine temperatures reach a high of 1 °C. Light ridge wind. Freezing level rising to 2300 meters.
WednesdayA mix of sun and cloud. Alpine temperatures reach a high of 2 °C. Ridge wind light to 15 km/h. Freezing level rising to 2400 meters.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Start on smaller terrain features and gather information before committing to bigger terrain.
- Stay off recently wind loaded slopes until they have had a chance to stabilize.
- Be alert to conditions that change with elevation and sun exposure.
Problems
Wind Slabs
Strong southerly winds during last week's storm have created deep deposits of wind slab near ridges and peaks. These slabs are most likely to be an issue inland from the coast, where the storm snow was deep, dry, and will take more time to settle and gain strength.
If northerly outflow winds pick up on Monday, fresh wind slabs may form anywhere there is powdery, dry snow available to be transported. Watch for changing conditions throughout the day and avoid freshly wind-loaded terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 12th, 2022 4:00PM
