Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Regions
Glacier.
Settling storm snow is sitting on a weak layer that is reactive to human triggers. Natural avalanche activity is dropping off, but careful decision making is essential.
Weather Forecast
Mainly cloudy today with isolated flurries and ridge winds gusting to 50km/h from the SW. Freezing level will rise to 900m with an alpine high of -8. Isolated flurries will continue until Saturday morning. For the holiday weekend, a high pressure ridge is expected to form bringing clear skies and cool temperatures until the next storm arrives.
Snowpack Summary
The recent storm snow has remained light and powdery for the past couple of days but we are starting to see settlement and the formation of a storm slab. Strong SW winds have formed wind slabs on lee features. The new slabs are poorly bonded to the December 18th interface of facets and surface hoar. All of this sits on a weak, facetted snowpack.
Avalanche Summary
Numerous natural avalanches were observed yesterday morning in the highway corridor ranging from size 2.5 to 3. On Tuesday a skier was partially buried by a skier accidental size 1 avalanche in the Asulkan drainage. It was 30-50cm deep and failed on the Dec 18th (see their MIN). They also remotely triggered a size 1.5 on a SW aspect.
Confidence
Due to the number of field observations
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.
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.