Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period
Weather Forecast
Sunday night: Strong SE winds. Freezing level at surface. 10-15 cm snow.Monday: Strong winds changing from SE to W. Alpine temp lowering to -10. A few cm snow.Tuesday: Light to moderate SE winds. Alpine temp -7. Very light snow. Wednesday: Light SE winds. Alpine temp -11. 20 cm snow.
Avalanche Summary
Recent activity has been limited to a few small (size 1) soft slab avalanches in immediate lee features and small loose snow avalanches in steep terrain. Observations from early last week included several old size 2-3 avalanches, primarily from northerly aspects in the alpine. These events may have released on a weak layer of surface hoar, now down over a metre deep.
Snowpack Summary
Up to 50 cm of new snow may have buried a thin layer of surface hoar in some areas. Recent winds have been stiffening the low density storm snow and forming reactive slabs in exposed lee terrain. Below the recent storm snow weaknesses, the snowpack is well settled and strong. A layer of surface hoar that formed during late November has been found intact or decomposing in some locations down a metre or more. The early November crust/facet combination near the base of the snowpack seems to be dormant, at least in deep snowpack areas where it is buried too deeply by a stiff snowpack to be affected by light triggers on the snow surface.
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.