Watch for signs of fresh wind slabs, such as stiff or slabby snow and blowing snow at ridgetops. If you've been out in the mountain please share your obs on the Mountain Information Network (MIN).
Confidence
Moderate - Forecast snowfall amounts are uncertain on Thursday
Weather Forecast
WEDNESDAY: Cloudy with isolated flurries, 40-60 km/h west winds, alpine temperatures -10C.THURSDAY: 10-20 cm of new snow, 60-80 km/h west winds, alpine temperatures -8C.FRIDAY: Cloudy with isolated flurries, 20-40 km/h northwest winds, alpine temperatures -10C.
Avalanche Summary
On Tuesday, new storm snow produced numerous size 1.5-2 avalanches, including natural and skier-triggered loose dry avalanches on north and east aspects.Wind slabs will become the primary concern for human-triggering on Wednesday, with winds forecast to increase. Loose dry avalanches will also be likely in steep features sheltered from the wind.
Snowpack Summary
The region received up to 50 cm of low density snow on Tuesday, which is now available to be redistributed by strong westerly winds. The new snow sits above a variety of surfaces including old hard wind slabs and surface hoar. The cold weather in early December left several layers of weak surface hoar and facets which are now buried 50-80 cm deep. These layers have been inactive for the past week, as it appears the lower snowpack is well-settled. A thick crust rain crust from mid-November is near the bottom of the snowpack and remains well bonded to the surrounding snow.
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.