Avalanche Forecast
Issued: Nov 28th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
dboucher,
Avalanche Canada
Please respect all restrictions on BC highways.
Recent snowfalls at higher elevations have developped storm slabs that could trigger deeper weak layers and produce large avalanches.
Summary
Confidence
Low - Uncertainty is due to limitations in the field data.
Weather Forecast
 A weak ridge of high pressure will bring a break between storms with mainly quiet conditions for Monday.Â
Sunday night: Moderate rain or flurries; 5-10 cm. Moderate to strong southwest winds. Alpine low temperatures -3 C with freezing levels going down to 1600 metres.
Monday: Mainly cloudy with isolated flurries. Moderate southwest winds. Alpine high temperatures -2 C with freezing levels steady at 1700 metres.
Tuesday: Periods of snow; 5-10 cm. Strong southwest winds. Alpine high temperatures -2 C with freezing levels at 1700 metres.
Wednesday: Wet snow mixed with rain; 10-20 mm. Strong southwest winds. Alpine high temperatures +2 C with freezing levels up to 1700 metres in the north of the region and 2800 metres in the south of the region.
Avalanche Summary
Large avalanches sliding on recently buried surface hoar and deeper buried crusts have been observed in the region as well as in the neighboring Sea to Sky.
Reports in the region remain limited. Be sure to post your observations to the Mountain Information Network !
Snowpack Summary
With freezing levels going down overnight, a crust will develop at the surface at treeline and will be covered by 5-10 cm of new snow. In the high alpine, thick storm slabs are likely to be found in lee terrain features.
Recent snowfalls sit over a layer of surface hoar or crust down 60-90 cm that produced avalanche activity in neighboring Sea to Sky region. Deeper in the snowpack, a hard rain crust sits around 70-110 cm below the surface, or shallower on windward slopes. Another rain crust exists near the bottom of the snowpack.
Average snowpack depths in the alpine are now 130-180 cm. Below treeline, depths of 30-50 cm have been reported around 500 m, decreasing dramatically with elevation, and still below threshold for avalanching in many areas.
Early season hazards such as rocks, stumps, and creeks are a concern below the alpine.
Terrain and Travel
- In times of uncertainty conservative terrain choices are our best defense.
- Be mindful that deep instabilities are still present and have produced recent large avalanches.
- If triggered, storm slabs in-motion may step down to deeper layers and result in very large avalanches.
Problems
Storm Slabs
Recent snowfalls at higher elevations have developped storm slabs above a weak layer of surface hoar and/or a deeper crust. Thicker storm slabs are likely to be found in lee terrain features.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A deep weak layer affecting alpine areas could result in very large, full-path destructive avalanches.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Nov 29th, 2021 4:00PM
