Avalanche Forecast
Issued: Jan 4th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
mconlan,
Avalanche Canada
It may take some time for all the recent snow to stabilize. Conservative terrain travel is needed.
Summary
Confidence
Weather Forecast
TUESDAY NIGHT: Evening snowfall then clearing skies, accumulation 5 cm, 10 to 20 km/h northwest wind, alpine temperature -13 C.
WEDNESDAY: Partly cloudy with no precipitation, 10 to 20 km/h west wind, alpine temperature -12 C.
THURSDAY: Cloudy with snowfall, accumulation 15 to 30 cm, 50 km/h southwest wind, alpine temperature -7 C.
FRIDAY: Cloudy with snowfall then clearing, accumulation 10 cm, 20 km/h west wind, alpine temperature -7 C.
Avalanche Summary
A widespread avalanche cycle was observed within the storm snow on Sunday and Monday. More storm slab avalanches were observed on Tuesday from explosives and riders. The avalanches were generally small to large (size 1 to 2). The likelihood of humans triggering the storm snow remains elevated.
Snowpack Summary
Over 100 cm of snow has accumulated since January 1. The snow has formed touchy storm slabs in sheltered terrain and wind slabs in exposed terrain from strong southerly winds.
The storm snow overlies various layers that formed during the cold spell in late December. These layers include a melt-freeze crust on sun-exposed aspects, weak and feathery surface hoar in areas sheltered from the wind, weak and sugary faceted grains, and hardened surfaces from strong wind. There is uncertainty in how long it will take for the storm snow to bond to these layers.
A weak layer of faceted grains may be found above a widespread melt-freeze crust that formed in early December. This layer is likely found anywhere from 100 to 250 cm deep. This layer was the culprit of large, destructive avalanches in December. It has been most reactive between 1700 and 2100 m.
The lower snowpack is well-settled and strong.
Terrain and Travel
- Choose conservative terrain and watch for clues of instability.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Stick to simple terrain and be aware of what is above you at all times.
- Be aware of the potential for large avalanches due to the presence of a persistent slab.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Problems
Storm Slabs
Touchy storm and wind slabs have formed from the 100+ cm of snow that fell since January 1. Wind slabs are likely found in wind-affected terrain from strong southerly wind and storm slabs are found in terrain sheltered from the wind. These slabs will likely remain touchy, particularly where they sit on weak snow or hard surfaces.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
A weak layer of faceted grains above a hard melt-freeze crust may be found around 100 to 250 cm deep. This layer is most prominent between 1700 and 2100 m. All the recent storm snow has loaded this weak layer, increasing the likelihood of triggering it. Humans are most likely to trigger it where it is spatially shallow, for example in thin, rocky snowpack areas.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 5th, 2022 4:00PM
