Regions
Kootenay Boundary.
Heavy snowfall and wind has resulted in HIGH avalanche danger at higher elevations.
Weather Forecast
THURSDAY: Another 5 to 10 cm is expected by Thursday evening with SW winds. Continued warm with freezing level steady around 1300mFRIDAY: Still snowing with 10 to 20cm forecast by Friday evening with strong SW winds. Continued warm with freezing level unchanged (around 1300m).SATURDAY: Scattered flurries with light snowfall, moderate southwesterly winds and freezing levels around 1000 m.
Avalanche Summary
Explosive control at treeline and alpine elevations released storm slabs 30 to 60 cm deep on Monday. Loose dry sluffing up to size 1.5 from steep terrain at all elevations was also reported on Monday and Tuesday. Slab avalanche size and likelihood is expected to increase with forecast new snow, wind, and warming.
Snowpack Summary
Another 10-20cm adds to the 30 to 50 cm from the past few days with deepest amounts in eastern areas. Wind slabs have formed in exposed areas from shifting SW to NW winds and more snow and wind is forecast. Recent snow rests on a sun crust on steep sun-exposed slopes and large surface hoar shaded aspects. Below that are a variety crusts and thin surface hoar layers, depending on aspect and elevation, with the primary mid-pack feature being the mid-February surface hoar/sun crust down 75-100 cm. Areas with a shallow snowpack (less than around 170 cm) generally have a weak snowpack structure with a deep persistent weakness of facets near the ground.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.