Regions
South Coast Inland.
Storm slabs will likely be most reactive in wind effected terrain. Avoid slopes where the snow feels stiff or slabby.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Wednesday: Mostly cloudy / Light, southeasterly winds/ Freezing sea level.Wednesday night: 10-15 cm new snow / Light to moderate, southerly winds / Freezing level sea level.Thursday: 20-25 cm new snow / Strong, southwesterly winds / Freezing level 800m.Friday: Mix of sun and cloud / Moderate, westerly winds / Freezing level 800 m.
Avalanche Summary
A skier triggered size 1 persistent slab avalanche on a small convex feature southest of Bralorne. The weak layer was down 50 cm and suspected to be the surface hoar/facet layer that was buried in mid-January. This layer has been largely dormant but may become active in isolated locations where the weak layer is well preserved. Continue to dig down and test this weak layer to monitor its reactivity.
Snowpack Summary
35-50 cm(lower amounts in the north) of recent storm snow has buried a wide variety of old snow surfaces including stiff wind slab or wind effected snow at upper elevations, sun crust on steep southerly slopes, surface hoar and surface facets in sheltered locations. The mid-January surface hoar and facet interface is now buried 50-80 cm and the mid-December facets down 90-120 cm remain a concern especially in shallower snowpack areas like the Duffey, Hurley and/ or South Chilcotins. These deeper weaknesses warrant monitoring especially through periods of more load. In southern areas (Coquihalla), the lower snowpack is reportedly well settled(stronger), than it is to the north.
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.