Regions
South Coast Inland.
Natural and human triggered avalanches remain very likely on Friday. Travel in avalanche terrain is not recommended.
Weather Forecast
Thursday night: 15-30 cm new snow / Strong, southwesterly winds/ Freezing level dropping to around 1000m.Friday: 15-20 cm new snow / Strong, southwesterly winds / Freezing level around 800 m.Saturday: Mix of sun and cloud / Moderate, southwesterly winds/ Freezing level hovering around 1000 m.Sunday: Mix of sun and cloud / Light to moderate, southwesterly winds / Freezing level rising to around 1500 m.
Avalanche Summary
Forecast continued heavy snow and strong winds Thursday night and into Friday are keeping the avalanche danger HIGH on Friday.
Snowpack Summary
An additional 40+ cm of snow on Thursday added to the 35-50 cm(lower amounts in the north) of recent storm snow that is sitting on 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 90-120 cm and the mid-December facets down 130-160 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 rapid loading. 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.