We've had lots of new snow and the winds are just starting to ramp up. We had a close call yesterday with a rider triggered avalanche. Reactive surface hoar as well as storm snow instabilities should be enough to stick to conservative terrain.
Weather Forecast
Continued north west flow over the Interior bringing cloud, light snow today and cool temperatures. Slight break between storms for most of today until this evening when the next wave will arrive. Moderate to heavy snow is forecast with stronger winds, from north and south depending on elevation into Tuesday night. High pressure ridge for Wednesday
Snowpack Summary
Recent storm snow amounting to over 50cm over wind slabs in exposed areas. The Dec 17th surface hoar layer is down 70-100cm sitting on top of a thick rain crust facet combo below 2100m and over a settled snow above. This widespread layer has been most reactive at tree line. Well settled mid-pack over top the basal Nov 9 crust.
Avalanche Summary
Yesterday, a size 2.0 skier accidental avalanche in Teddy Bear trees. East aspect, ~2000m, ~35 degrees, ~65cm deep, 40-50m wide, ~150m long. Avalanche was triggered near the ridge crest and rider went for a ride through the trees. Slabs pulled out lower down as well. Several large natural avalanches within the highway corridor early this morning.
Confidence
Intensity of incoming weather systems is uncertain
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
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.