Dangerous avalanche conditions exist in areas with more than 25 cm of new snow. Current snowpack and weather conditions are highly variable.
Recent reports of avalanches on buried surface hoar layers (including this MIN report) suggest that a persistent slab problem has developed. Persistent slabs will become more reactive with the additional load of new snow. While there is uncertainty about the distribution of this problem, sheltered slopes around treeline elevations are most the suspect.
Expect unstable slabs to form as more snow accumulates, especially at higher elevations and wind loaded slopes near ridges.
MONDAY NIGHT: Scattered flurries with up to 15 cm of new snow, strong wind from the west, alpine temperatures around -2 C.
TUESDAY: Scattered flurries with 5-10 cm of snow and light rain below 1000 m, light wind from the south with moderate gusts, alpine temperatures around -2 C.
WEDNESDAY: Snow with accumulations of 15 cm, moderate wind from southwest, alpine high temperatures drop from -2 to -6 C.
THURSDAY: Cloudy with isolated flurries, light wind, alpine high temperatures around -8 C.
Stormy weather is likely forming unstable storm slabs and wind slabs, as well as adding stress to buried surface hoar layers. There are reports of recent large natural avalanches in the Telkwa Range (size 2-3), mostly on northeast aspects. Some were likely triggered by cornices, while many appear to have run on the buried surface hoar layers. A size 1.5 skier-triggered avalanche was reported in the Ashman area on Friday. The avalanche occurred on a convex north-facing slope at treeline and also failed on a surface hoar layer 50 cm below the surface (see full report and photos in this MIN post).
Recent snowfall amounts have been variable across the region and forecast amounts are uncertain for Tuesday and Wednesday, but there are likely storm slabs developing in parts of the region. Reports suggest there are two layers of surface hoar buried 25-50 cm below the surface. A skier triggered avalanche at Ashman and snowpack test results near Smithers suggest these layers have now become reactive. There is uncertainty about the distribution of this layer, but the sheltered slopes around treeline elevations are the most suspect for having preserved surface hoar.
