Avalanche Forecast
Issued: Mar 11th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
rgoddard,
Avalanche Canada
Assess snow stability as you transition into wind-affected terrain and monitor how new snow is bonding to old surfaces.
Minimize time traveling on slopes below cornices. In shallow snowpack areas, a cornice fall could trigger a deep persistent slab avalanche.
Summary
Confidence
Moderate
Avalanche Summary
A cornice-triggered size 1.5 wind slab avalanche was reported on a northwest aspect in the alpine in the Duffey zone on Tuesday. No significant avalanches were reported since then.
Snowpack Summary
Snow arriving Saturday night and into Sunday will be falling on a sun crust on solar aspects. New and old wind slabs can be found near ridge crests in the alpine and treeline. These slabs sit on a variety of surfaces including sun crusts, facets, and previously wind-affected terrain. These recent winds have also formed large cornices. Around 20 cm of soft snow can be found in sheltered terrain.
The mid-snowpack is well consolidated.
This is not the case for the lower snowpack. There is a widespread weak layer of large sugary facets at the bottom of the snowpack. Recent avalanche activity on this layer has been confined to northern parts of the region in the Chilcotins. This layer remains a concern in shallow snowpack areas.
Weather Summary
Saturday Night
Mostly cloudy, 5 to 10 cm accumulation in the northwestern sections, winds south 20 to 25 km/h, treeline temperatures -8 °C.
Sunday
Mostly cloudy, 5 cm accumulation, winds south 20 km/h gusting to 40, treeline temperatures -5 °C with freezing levels to 1300 m.
Monday
Cloudy, 10 to 20 cm accumulation, winds southwest 25 km/h gusting to 45, treeline temperatures -7 °C with freezing levels at 1200 m.
Tuesday
A mix of sun and cloud, trace accumulation, winds southwest 20 km/h gusting to 40, treeline temperatures -10 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
- Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Closely monitor how the new snow is bonding to the crust.
Problems
Wind Slabs
Snow falling Saturday night and into Sunday will be redistributed by southerly winds. Reactivity may be heightened due to wind slabs forming on a crust.
Aspects: North, North East, East, South East, South West, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A layer of weak facets sits near the base of the snowpack. This layer is most likely to be problematic in steep, wind-loaded terrain where the snowpack depth varies from thick to thin. Especially in the northern part of the region around the Chilcotins, Birkenhead, and Hurley.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 12th, 2023 5:00PM
