Avalanche Forecast
Issued: Dec 29th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
jleblanc,
Avalanche Canada
Challenging traveling conditions will exist at treeline and below. Be aware of the potential for wide propagation in the alpine, as wind slabs may rest on surface hoar, facets and/or crust.
Summary
Confidence
Moderate
Avalanche Summary
On Friday, numerous cornice falls were reported due to intense alpine warming. Natural small loose wet avalanches were also observed on steep terrain at all elevations. On Thursday, small wind slabs and storm slabs (up to size 1.5) were skier-triggered on convex lee slopes at treeline north of Pemberton. They mostly ran on the concerning surface hoar layer or a buried crust down 30 cm.
Snowpack Summary
The surface snow has been moist up to 2200 m as a result of warm temperatures on Friday. Between 30 and 65 cm of recent storm snow and heavily wind-affected snow overlies a thick crust and, in some sheltered areas, surface hoar. This layer has bonded poorly in neighbouring regions to the west and south, and in parts of this region could result in large wind slab avalanches. Recent natural avalanche activity has been involving these layers. Overall, the snow depth remains shallow, with average treeline snowpack depths between 80 and 120 cm.
Weather Summary
Friday Night
Partly cloudy with no precipitation, alpine wind south 30 to 40 km/h, treeline temperature around -2 °C, freezing level lowering to 1500 m.
Saturday
Cloudy with 3-5 cm of snow, alpine wind southwest 30 to 50 km/h, treeline temperature around 0 °C, freezing level at 1800 m.
Sunday
Mix of sun and clouds, no precipitation, alpine wind southwest 20 km/h, treeline temperature around -3 °C, freezing level around 1200 m.
Monday
Mix of sun and clouds, no precipitation, alpine wind southwest 20 to 30 km/h, treeline temperature around -4 °C, freezing level at valley bottom.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Wind slabs may be poorly bonded to the underlying crust.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- A crust on the surface will help bind the snow together, but may make for tough travel conditions.
Problems
Wind Slabs
Wind slabs will remain reactive to human triggering above 2000 m. There is a potential for wide propagation as slabs may rest on surface hoar and/or crust.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Dec 30th, 2023 4:00PM
