Reactive storm slabs continue to build at higher elevations and thicker slabs will likely exist on leeward slopes due to wind redistributed storm snow. At lower elevations, loose wet avalanches are likely as rain soaks the snowpack.
Upside-down storm slabs sit over a slippery crust. Natural avalanche activity is expected to continue with precipitation into Wednesday.
As rain soaks the snowpack at lower elevations, loose wet avalanches will become increasingly likely.
Strong southwesterly winds result in an onshore flow of a cool, and unstable air mass. This brings moderate to heavy snow at upper elevations for the Vancouver Island ranges and the Coast Mountains.
Tuesday Night: 10-15 mm of precipitation expected with strong southwest winds. Freezing levels 1400 m bringing snow to upper elevations.
Wednesday: Another 10 mm of precipitation falling as snow above 1300 m. Strong southwest wind continues.
Thursday: Drying and cooling trend with the freezing level dropping to 1000 m with light northwest winds at ridgetopn and clearing skies.
On Tuesday, numerous size 1 wet loose avalanches were reported at below treeline elevations. Poor visibility made for limited alpine observations.
On Monday, our field team observed widespread natural avalanche activity size 1-2.5. A skier-triggered size 2 storm slab was reported at Mt Cain on Sunday in this MIN.
The recent storm snow is topped with a thin freezing rain crust and 5 cm of recent moist snow. Within the 40-60 cm of new snow, a wet layer on the surface is stacked on top of lower density, dry snow. This configuration is referred to as upside-down and is often associated with short-term instability while the soft bottom settles. Above ~1900 m, the surface remains dry and has seen extensive wind effect, with extremely variable depths and areas of hard wind slab.
The storm snow sits over a thin layer of weak crystals on a thick, widespread rain crust which makes a great sliding surface for avalanches. This crust is capping a well settled and strong mid and lower snowpack. Shallow snow cover at low elevations leaves many hazards like stumps and creeks exposed at or just below the snow surface.
