Fresh storm slabs will be driving the avalanche danger on Tuesday. Be extra vigilant on down wind (lee) features below ridge crests.
Confidence
Moderate - Intensity of incoming weather systems is uncertain on Tuesday
Weather Forecast
Active weather returns on Tuesday with moderate amounts of snow and cool temperatures. TUESDAY: Snow. 5cm overnight with 10-15cm accumulation throughout the day. Ridge wind moderate from the east. Temperature near -5. Freezing level 500 m.WEDNESDAY: Sunny with cloudy periods. Ridge wind moderate northerly. Freezing level at the surface.THURSDAY: Cloudy with isolated flurries. Ridge wind moderate from the north west. Temperature near -3. Freezing level 400 m.
Avalanche Summary
On Monday, ski cutting and explosives control work produced several Size 1 to 1.5 storm slabs on steep northerly features at higher elevations. On Sunday, natural and cornice triggered storm slabs to Size 1 were reported on northerly aspects in the alpine.
Snowpack Summary
10-30 cm of new snow covers the melt-freeze crust that formed on all aspects and elevations in early December. On high north aspects this crust is thin with dry, sugary snow crystals (facets) below. Moderate winds from the south (west) have redistributed snow, creating isolated soft slabs on downwind slopes and behind ridges (north through east aspects). Beneath the surface, the upper snowpack is well settled and overlies a thin layer of facets on the late-November rain crust, which is now down approximately 60 cm at tree line elevations. The lower snowpack is well settled and consists of several crusts that formed in the early season.
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.