Upslope snow is forecast on Friday. We are expecting 5-10 cm in most areas but may see more in eastern and southern parts of our forecast region.
Strong to extreme NW winds this week have formed wind slabs in lee features of the alpine and at treeline elevations. These will be buried by 5-10 cm of snow on Friday and may become harder to identify.
The lower snowpack is comprised of weak facets and depth hoar with the upper snowpack forming a 40 to 90 cm thick slab above. NW winds, snow and a big temperature drop this week may make this layer more sensitive to triggering for the next few days...
Sunshine and Lake Louise ski hill reported isolated, small skier controlled avalanches in wind loaded alpine and treeline features. Sunshine also noted a fresh size 2 cornice failure out of steep alpine terrain that didn't pull a slab on the slope below.
Recent strong to extreme winds have created widespread wind effect and windslabs in the alpine and treeline. Below this, the upper snowpack contains weak layers 10-30 cm deep (Jan. 4th) and 25-50 cm deep (Dec. 17th) that are generally unreactive. The Nov 16 deep persistent layer is down 40-90 cm and continues to produce sudden results in test profiles. In areas west of the divide, these layers are generally deeper and more spread apart in the snowpack.
Strong NW winds continue Thursday night until a cold front arrives and arctic air moves in. The cold front turns upslope giving more snow on the eastern and southern parts of our forecast region.
Fri: 5-10 cm snow. Alpine winds decreasing to moderate to light from the north. Temperatures cooling to -15.
Sat: Cold and partly cloudy. Alpine temps of -20 to -25. Winds light from the north.
Sun: Cold and sunny. Alpine temps -30 to -20. Winds moderate from the north.
