Regions
Banff Yoho Kootenay.
The cold has taken its toll on the snowpack, with facets galore. Watch for small wind slabs in steep alpine features, and loose dry sluffs in the facetted snow. These will be small but can run far and fast.
Weather Forecast
Another savagely cold morning for Sunday with lows between -30 and -35C, light NE winds and no snow. A very slow gradual warmup will occur over the week with no real snow in the forecast. The plus side is if you can bear the cold start, the sun is getting stronger which will make things bearable.
Snowpack Summary
Cold temperatures continue to weaken the surface snow. Wind effect is common in the alpine and several recent crusts can be found on steep solar slopes. Despite the weakening slab above it, Jan 17 surface hoar lingers down 40-60 cm in isolated locations and produces hard, resistent shears. A weak basal snowpack exists in thin snowpack areas.
Avalanche Summary
Some reports of fresh wind slabs triggered by explosives and skiers, and loose snow avalanches or 'point release sluffs' . Given the right terrain these sluffs can amount to significant avalanches: they start slow but gain mass quickly and would be very 'real' for those caught in a terrain trap such as above a cliff or in a gully
Problems
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.
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.