Avalanche Forecast
Issued: Dec 5th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
dsaly,
Avalanche Canada
Look for powder in depressions and sheltered features. Watch for reactive snow around ridges and in steep terrain.
Summary
Confidence
Moderate - The snowpack structure is generally well understood.
Weather Forecast
SUNDAY NIGHT: Mostly cloudy with isolated flurries. Decreasing southwest-west wind, 5-15 km/hr. Alpine low temperature -18 C. Freezing level valley bottom.Â
MONDAY: Cloudy with isolated flurries, trace to 5 cm accumulation. Light and variable wind 10-20 km/hr. Alpine high temperature -8 C. Freezing level valley bottom.Â
TUESDAY: Mostly cloudy, flurries in the afternoon. Southwest wind increasing to 30 km/hr. Alpine high temperature -9 C. Freezing level valley bottom.Â
WEDNESDAY: Snow beginning overnight, 5-20 cm accumulation. Increasing southwest wind, 30-40 km/hr. Alpine high temperature -8 C. Freezing level below 1000 m.Â
Avalanche Summary
A natural cornice failure was reported on Friday, Dec 3. The small cornice did not trigger the slope below.
On Thursday, Dec 2, explosives triggered size 1-2 avalanches above 1800 m, with the larger (size 2) avalanches reported above 2000 m and included cornice failures triggering slopes below.
On Wednesday, Dec 1, explosives triggered size 1 loose wet and storm slab avalanches near Revelstoke.
The recent series of atmospheric rivers onslaught brought heavy precipitation, strong winds, and warm weather. Widespread and very large natural avalanche cycles were observed (up to size 3) following each wave of storms, with avalanches frequently running full path to valley bottom. No new natural avalanches have been reported since Dec 1. Hard frozen debris will likely be found in the runout of most avalanche paths.
Snowpack Summary
Up to 25 cm recent snow covers a crust, which is exposed in open terrain. At treeline and above, pockets of wind slab up to 40 cm deep are found in lee features, with fun powder in protected areas and depressions.
Below the Dec 1 surface crust, the snowpack is generally well-consolidated with a few early season crusts. The mid-November crust is found down 70-150 cm with faceting below the crust; this feature disappears above 1900 m.
Snowpack depths range from 120-250+ cm at treeline and above. Below 1600m the snowpack decreases rapidly.
Check out our latest Forecaster Blog here.
Terrain and Travel
- Be careful as you transition into wind affected terrain.
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
Problems
Wind Slabs
Wind slabs may lurk around ridges and steep terrain. Be mindful transitioning into steep alpine-like features at treeline.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 6th, 2021 4:00PM
