Avalanche Forecast
Issued: Nov 25th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
mconlan,
Avalanche Canada
Welcome to the first forecast of the season! The bond of the recent snowfall is what to investigate, particularly where substantial amounts of snow may have accumulated at higher elevations.
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations.
Weather Forecast
WEDNESDAY NIGHT: Partly cloudy, light northwest wind, treeline temperature -2 C, freezing level 1000 m.
THURSDAY: Cloudy with late afternoon snowfall, accumulation 5 cm, moderate west wind, treeline temperature -1 C, freezing level 1100 m.
FRIDAY: Cloudy with snowfall, accumulation 20 cm, strong southwest wind, treeline temperature 0 C, freezing level 1400 m.
SATURDAY: Early-morning snowfall then clearing, accumulation 30 to 40 cm, moderate west wind, treeline temperature -3 C, freezing level 1000 m.
Avalanche Summary
Small slabs about 20 cm thick were triggered by skiers on the North Shore Mountains on Monday. We have not received any information since Tuesday's storm, but we suspect that similar avalanches could be triggered within Tuesday's storm snow, particularly at higher elevations.
Our eyes and ears in the mountains are limited at this time of year and may continue this winter due to fewer professional observations. If you see anything while out in the field, please consider sharing it with us and fellow recreationists via the Mountain Information Network (MIN). Even just a photo of where you went is helpful. A big thank you to those that have already shared their observations thus far.
Snowpack Summary
The snowpack depth rapidly changes with elevation. The snowline has been reported to be around 900 m. The snowpack rapidly jumps to around 100 cm deep above 1000 m and between 150 to 200 cm near the mountain tops.
Tuesday's storm dropped a mix of snow and rain at most elevations, with it only falling as snow above about 1500 m. Around 30 cm may have accumulated above 1500 m whereas 10 to 15 cm of moist snow likely accumulated below. Deeper deposits should be expected in lee terrain features at higher elevations.
Numerous melt-freeze crusts and ice layers exists in the snowpack and reports indicate that the surrounding snow is well-bonded to them.
Terrain and Travel
- Investigate the bond of the recent snow before committing to your line.
- Be alert to conditions that change with elevation.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Be cautious of buried obstacles especially below treeline.
Problems
Storm Slabs
Tuesday's storm dropped around 10 to 15 cm of snow below about 1500 m and upwards of 30 cm above. Check for the bond of this new snow before committing to avalanche terrain. The snow may be touchier adjacent to ridges, where the wind may have formed locally deeper deposits.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Nov 26th, 2020 4:00PM
