Regions
Banff Yoho Kootenay.
Sluffing is becoming an issue as the surface snow facets. Dress warm and enjoy the holidays!
Weather Forecast
The arctic air continues to be entrenched over us for the foreseeable future. At treeline overnight lows will be in the low -20's with day time highs in the -16 to -14 range. Expect light to moderate winds from the NW with a mix of sun and cloud. A few isolated flurries are forecast for Wednesday but no significant accumulations are expected.
Snowpack Summary
Upper snow-pack is facetting with the cold temperatures and starting to sluff easily in steep terrain. Some thin, hard wind slabs observed in lee areas in the alpine. The Dec.15 layer of surface hoar (below 2100m) and hard surfaces or facets (depending on location) is down 15-30 cm. Some moderate shears have been observed around this interface.
Avalanche Summary
Only a few small thin wind slabs and loose dry sluffs out of steep terrain have been reported over the last four days.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.