Regions
Banff Yoho Kootenay.
New surface snow is running far and fast below treeline on steep features. They are powerful enough to knock someone over or carry someone to an undesirable location at high speed.
Weather Forecast
For the next few days expect overcast skies, small amounts of snow (virtually a trace) and moderate to strong wind at higher elevations from the west. This combination of factors will produce small windslabs in lee areas in the alpine. The wind is expected to die down on Friday.
Snowpack Summary
Varying amounts of snow fell across the forecast region in the past 24hr. Most of this was in Kootenay with 10-15cm, less in other areas. The new snow sits on top of a generally weak and faceted snowpack due to the recent cold clear period. When more snow load arrives, expect to see a significant avalanche cycle.
Avalanche Summary
1 size 1.5 natural avalanche was reported on an open slope on the treed should of Mt. Hector. This was triggered by new snow loading onto an old windslab. It ran for 300m. Additionally, the new surface snow was sluffing far and fast on steep features below treeline adjacent to Vermillion Peak today.
Confidence
Due to the quality of field observations on Tuesday
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.