Avalanche Forecast
Issued: Mar 14th, 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.
ahanna,
Avalanche Canada
Snowfall amounts will vary throughout the region Tuesday. The danger rating reflects forecast snowfall for the Coquihalla. In areas that receive less than 15 cm, avalanche danger may be a step lower. Make observations and assess conditions as you travel.
Summary
Confidence
Moderate - Recent weather patterns have resulted in a high degree of snowpack variability within the region.
Weather Forecast
Monday night: Snowfall 5-15 cm, 30-50 km/h southwest wind, alpine temperature -5 C. Freezing level 1300 m.
Tuesday: Snowfall 5-10 cm in the north, 10-20 cm in the south, 40-50 km/h southwest wind, alpine temperature -5 C. Freezing level 1500m.
Wednesday: Overnight snowfall 5-10 cm then mostly cloudy, 20-30 km/h southwest wind, treeline temperature -5 C. Freezing level 1400 m.
Thursday: Snowfall starting around 5 cm, 20-30 km/h south wind, treeline temperature -4 C. Freezing level 1500 m.
Avalanche Summary
No new avalanche observations since Wednesday when a rider triggered a persistent slab avalanche along the Duffey at 2000 m on a northeast aspect. Another suspected persistent slab avalanche was triggered by a rider on Tuesday in the north of the region. Both slabs were around 30 to 40 cm thick, resulting in small avalanches (size 1 to 1.5). It remains possible that humans could trigger this layer, where it exists.
Snowpack Summary
New snow accumulates over variable surfaces including a hard melt-freeze crust on solar aspects and low elevations, previously wind-affected snow at higher elevations and perhaps a thin layer of surface hoar or faceted snow in sheltered areas.
Around 30 to 60 cm deep, sugary faceted grains may be found around a melt-freeze crust that formed February in the north of the region (e.g., Duffey, Hurley). The layer has been most prevalent on north to northeast aspects around 1900 to 2100 m. Check out this forecaster blog for more info.
Various crusts may be found in the south of the region (e.g., Coquihalla, Manning) but reports suggest they are bonding to the snowpack and are not an avalanche concern.
There are no deeper concerns at this time.
Terrain and Travel
- Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
- Avoid freshly wind loaded terrain features.
- Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.
- Dial back your terrain choices if you are seeing more than 25cm of new snow.
Problems
Storm Slabs
Fresh storm slabs may be touchy and propagate widely if they bond poorly to the old surface.
In the north of the region where less snow is expected, the problem will be specific to wind loaded aspects at upper elevations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Portions of the north of the region (e.g. Duffey, Hurley) have a a weak layer of faceted grains above a hard melt-freeze crust that is found 30 to 60 cm below the snow surface. A few avalanches slid on it last week, with more activity observed in the neighbouring Sea to Sky region. It has been most problematic on north to northeast aspects around 1900 m to 2100 m.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 15th, 2022 4:00PM
