Facetting has refreshed the available snow for transport. Expecting a cold, weak new interface in lee features at all elevations. Stay away from steep terrain traps.
Variable wind direction over the past week has caused reverse loading in some areas. A 100km/hr wind event Sunday night has the potential to raise the Wind slab hazard for Sunday and Monday with potential for loading to occur further down slope.
Significant activity of this nature was noted in the Maligne range. Cold temperatures continue to cause the surface snow to loose its structure and be active particularly on steep alpine features and can run uncharacteristically far.
Recent avalanche observations have shown that deep persistent slabs can be initiated by large triggers such as surface avalanches or cornice failures.
Sunday: Mainly cloudy with scattered flurries. 5-10 cm. Temp: High -13 °C. Wind SW: 15 km/h.
Monday: Mainly cloudy with scattered flurries. 4 cm. Temp: Low -18 °C, High -10 °C. Wind S: 10-30 km/h.
Tuesday: Mainly cloudy with isolated flurries. Trace over the day. Temp: Low -28 °C, High -16 °C. Light ridge wind.
Cold temps are penetrating deep into the upper snowpack, promoting faceting. Wind slab pockets are present on all aspects, tree line and above. The mid-pack is supportive with the Dec 1st interface down ~40 cm in most locations. Basal faceting continues below the Nov 5 crust potentially amplifying the deep persistent slab problem.
Friday's Maligne patrol noted several loose dry up to size 1.5 running far on a previous hard surface. Avalanche Control on Medicine Slabs (steep, open treeline) produced several loose dry, and fast moving facet avalanches to the road.
