Avalanche Forecast

Moderate - Due to the number of field observations

It looks like the storm track on Saturday will head south of this region, with only minor snowfall amounts in the Cariboos. Clear and cold Sunday onwards, with overnight lows near -25 Celsius in some locations. Saturday: 2-5 cm new snow. Treeline temperature around -12C. Light winds becoming moderate north easterly. Sunday: Sunny but cold. Treeline temperatures around -17C. Winds light northeasterly.Monday: Sunny with cloudy periods. Treeline temperature around -15C. Winds light northerly.

On Thursday we received reports of recent cornice-triggered slab avalanches on high lee (down wind) features in the alpine. On Wednesday, several avalanches were reported in recent storm snow up to size 2.5. Previously, a very large, widespread natural avalanche cycle up to size 4 was observed last week. Slopes of all aspects and elevations ran full path and reached valley floor. In some cases, mature timber was destroyed. Many of these failed on persistent weak layers mentioned in the snowpack discussion. Although natural avalanche activity on these layers has tapered-off, human triggering of very large avalanches remains a very real possibility.

25-40cm of recent storm snow is settling into a slab in the upper snowpack. Winds have been strong from the north west through south west near Valemount, with reactive hard wind slabs (10-15 cm thick) forming in exposed locations on down wind features. See this MIN post for more information. These accumulations overlie a mix of older wind slabs in exposed higher elevation terrain, a sun crust on steep solar aspects and surface hoar on sheltered slopes.Below the snow surface, several persistent weak layers make up a troublesome snowpack. In the top 1-1.5 m of the snowpack, two surface hoar layers buried in January can be found. Expect to find at least one of these layers on all aspects and elevations.Deeper in the snowpack (120-200 cm deep) is a facet/crust/surface hoar layer from December, most prevalent at and below treeline.Near the base of the snowpack is a crust/facet combo, most likely to be triggered from thin spots in the alpine.All of these layers have produced large avalanches recently. The wide distribution and ongoing reactivity of these layers suggests that avoidance through choosing simple terrain is the best strategy.