Regions
Banff Yoho Kootenay.
Some new snow and wind will improve ski quality, but really watch for new wind slab development as well as spindrifting in alpine gully features. The first real arctic air is inbound starting Monday.
Weather Forecast
Another 5-15 cm with moderate Westerly winds are possible by Sunday morning with less amounts in the East. Temperatures will start to cool by Sunday evening as winds die down and we switch to a Northerly arctic flow. Expect temperatures to go sub -20 for the first part of next week.
Snowpack Summary
10-20cm of snow over the last 24 hours with moderate to strong SW winds creating wind slabs up to 30cm thick in lee alpine areas. A mid pack crust is allowing the snowpack to carry travelers fairly well except in shallow areas. We are watching for this crust to weaken but it is not producing avalanches yet.
Avalanche Summary
The Lake Louise region received enough new snow and wind to create fresh wind slabs up to size 2 in lee alpine features. These were reported as touchy in the morning but will settle out quickly. Other areas such as Sunshine ski area were reporting much smaller wind slabs only in the immediate lees of ridge features.
Confidence
Forecast snowfall amounts are uncertain on Sunday
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.