Avalanche Forecast
Issued: Dec 22nd, 2019 5:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is
dsaly,
Avalanche Canada
A huge amount of snow and rain has stressed the snowpack, and overloaded a weak crust deep in the snowpack.
Summary
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
Sunday Night: Cloudy with isolated flurries, trace accumulation. Alpine temperature -4 C. Moderate south wind with gusts to 50 km/hr. Freezing level 1100 m.
Monday: Scattered flurries, trace to 10 cm. Alpine temperature -4 C. Moderate southwest wind gusting to 55 km/hr. Freezing level 1200 m.
Tuesday: Mainly cloudy. Alpine temperature -8 C. Light southwest wind. Freezing level at valley bottom.
Wednesday: Mix of sun and cloud. Alpine temperature -10 C. Light west wind. Freezing level at valley bottom.
Avalanche Summary
Snow accumulation over the weekend overloaded deeply buried weak layers. A natural storm slab avalanche cycle to size 3 occurred Saturday and Sunday following intense and heavy loading from snow/rain and wind.Â
Skiers and snowmobiles triggered large (size 2) avalanches on Saturday. Explosives triggered very large (size 3-3.5) avalanches Saturday and Sunday, these avalanches failed on a deep persistent layer with some avalanche crowns over 200 cm. A complex avalanche problem has developed, read the latest forecaster blog here.
Snowpack Summary
Upwards of 60 cm of heavy snow has fallen since Dec 20. Snowfall at upper elevations covered a previously variable and wind-affected surface and produced reactive (and large) storm slab avalanches. Wind and additional flurries will add to slabs at higher elevations. Below 1500 m, rain saturated the snowpack.
Crust layers from November and October can be found 40-100 cm below the surface. The intense loading from new snow has overloaded these weak layers, producing very large (size 3) avalanches on Saturday and Sunday triggered by explosives.
Snowpack depths range between 60-130 cm at higher elevations and taper rapidly below treeline.
Terrain and Travel
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Be aware of the potential for large avalanches due to the presence of a deep persistent slab.
- Minimize exposure to overhead avalanche terrain, large avalanches may reach the end of runout zones.
Valid until: Dec 23rd, 2019 5:00PM
