Ongoing flurries and wind continue to build and develop slabs. Seek out sheltered slopes and watch for reactive pockets around steep rolls and ridge features.
20-35 cm of recent snow has been blown into wind slabs on lee and cross-loaded slopes in exposed areas. In some areas, the new snow buried an interface of weak, sugary facets that may be more prone to human triggering.
Monday night: Mostly cloudy, trace of snow, light southwest winds, alpine temperature -7 C.
Tuesday: Cloud cover increasing throughout the day, a trace of snow, moderate southwest winds, alpine high temperature -5 C.
Wednesday: Cloudy, 10-20 cm of snow, strong southwest wind, alpine high temperature -2 C, freezing level rising to 800 m.
Thursday: Mostly cloudy, 5-15 cm of snow, strong southwest wind, alpine high temperature -2 C, freezing level around 700 m.
Several natural and human-triggered wind slab avalanches were reported over the weekend (up to size 2.5). Over the past week, there have been reports of storm slabs (up to size 2) releasing on a faceted interface from mid-January (see an example in this MIN report).
There have been reports trickling in over the past month of natural persistent slab avalanches up to size 3 in the Bulkley Valley. These are thought to have been failing on the November crust/facet layer near the ground. The last reported activity at this interface was Monday January 13th.
South winds have drifted the recent 20-35 cm of snow (up to 50 cm in the Howson area) into slabs near and above tree line on lee and cross-loaded terrain features. These slabs sit on previously scoured surfaces from the arctic outflow winds or a weak layer of facets.
A layer of surface hoar now buried up to 1 m below the surface may also be found at treeline. A deep crust/facet layer lurks at the base of the snowpack. A couple of large avalanches are suspected to have run on this interface in the last few weeks. These larger avalanches have been specific to lee and cross-loaded features in the alpine.
