Avalanche Forecast
Issued: Dec 23rd, 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
Warm air may make the recent snow above the crust easy to trigger in steep terrain.
Summary
Confidence
High -
Weather Forecast
WEDNESDAY NIGHT: Clear skies, 20 km/h southwest wind, treeline temperature 0 C, freezing level 2500 m.
THURSDAY: Clear skies, 20 km/h southwest wind, treeline temperature 2 C, freezing level 2500 m.
FRIDAY: Cloudy with rain or snow, accumulation 10 mm or 10 cm, 20 km/h southeast wind, treeline temperature 1 C, freezing level 1600 m.
SATURDAY: Cloudy with snowfall, accumulation 20 to 30 cm, 40 km/h south wind, treeline temperature 0 C, freezing level 1300 m.
Avalanche Summary
Two skier-triggered avalanches were observed on Tuesday within the recent storm snow, as seen in the MINs here and here. The likelihood of triggering similar avalanches will remain possible until we see evidence that the snow is bonding to the underlying crust.
Snowpack Summary
Around 20 cm of snow overlies a hard melt-freeze crust up to around 1500 m. During this period of warm air temperature, the surface snow may rapidly form slabs that could slide easily on the crust. At the mountain tops, the snow may have been blown into thicker and touchy wind slabs on all slopes due to variable wind directions.
The remainder of the snowpack is well-settled and hosts numerous other melt-freeze crusts.
Terrain and Travel
- Closely monitor how the new snow is bonding to the crust.
- Avoid steep slopes when air temperatures are warm, or solar radiation is strong.
- Watch for areas of hard wind slab on alpine features.
- Cornices often break further back than expected; give them a wide berth when traveling on ridgetops.
Problems
Storm Slabs
Around 20 cm of snow overlies a hard crust. Unseasonably warm air may rapidly create slab properties within this snow and make it easy to trigger. If triggered, it should slide easily on the crust. Thicker wind slabs may also be found at the mountain tops on all aspects due to variable wind directions.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 24th, 2020 4:00PM
