Regions
Banff Yoho Kootenay.
Avalanche control will occur on Wednesday on Mt. Bosworth, Stephen, Field and Dennis. No skiing or climbing in any of these areas please. Conditions are changing with the new snow, warmer temps and wind. Stay in front of the change - it happens fast.
Weather Forecast
A system crossing the area overnight on Tuesday will deposit another 5-10 cm before it ends mid-day on Wednesday. Temperatures will remain in the -10 range and winds look to be generally light.
Snowpack Summary
Strong SW winds overnight Monday have redistributed recent snow into wind slabs in open areas above treeline. This recent snow sits over weak facets, previous wind effect or sun crusts on steep solar aspects. The mid pack varies from supportive in thicker snowpack areas to weak and completely faceted in thin areas.
Avalanche Summary
No new avalanches observed or reported on Tuesday, but small natural avalanches and spindrift were observed on Monday afternoon. Some of these traveled long distances entraining facets. Several skier triggered slabs have occurred in the last couple days, and avalanche control Sunday produced slabs up to size 2.5 running to treeline.
Confidence
Due to the number of field observations
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.