Ongoing snowfall and wind are driving avalanche hazard. Seek out sheltered areas and dig down to investigate deeper layers before committing to terrain.
Strong southwest winds continue to drift new snow into slabs on lee features in the alpine and exposed ridges near treeline. While natural avalanche activity has tapered, human triggering may still be likely. The wind slab problem overlaps with areas where cornices are also a concern.
A layer of weak, faceted snow from the previous cold snap is now buried 60-100 cm deep. This layer proved reactive during last week's storm cycle, but whether this layer will persist as a problem interface is uncertain. This persistent weak layer will likely be more problematic in shallower areas in the region where slab depths are in the 40-80 cm range and where the facets may be more pronounced.
Sunday night: Cloudy, 5-10 cm new snow, 15-20 cm near Kitimat, strong south winds, alpine temperature -3 C, freezing level dropping to 500 m.
Monday: Mostly cloudy, 5-10 cm of snow, moderate southwest winds, gusting strong, alpine high temperature -3 C, freezing level around 600 m.
Tuesday: Mix of sun and cloud, moderate south wind increasing to extreme overnight, alpine high temperature -3 C, freezing level around 400 m.
Wednesday: Mostly cloudy, 35-50 cm of snow, strong southwest winds, alpine high temperature -1 C, freezing level rising to 800 m.
Small pockets of human-triggered wind slab were reported at treeline elevations closer to Terrace, while larger (size 2-3.5) wind slabs were reported further north in the Bear Pass area releasing naturally from alpine start zones. Several of these avalanches released down to a weak layer formed in mid-January. During the weekend warm-up, numerous natural loose wet avalanches in steep terrain (size 1-2) were observed up to 1000 m.
Reports of deep persistent slab avalanches have been trickling in throughout the month, with the last reported event occurring on Jan 17th. They are associated with a November crust layer near the base of the snowpack which has produced very large avalanches (size 3+) with crown depths of around 2 m. These have typically run in alpine terrain, on lee or cross-loaded slopes. Recent loading has been a good test for this layer and it seems to be trending less reactive.
Around 60-100 cm of storm snow is settling rapidly. A recent warm-up moistened snow surfaces up to 1400 m over the weekend, which was described as "a thigh-burning, elephant snot mix of coastal pow-tatoes" in this MIN report.
In exposed areas above 1400 m, strong southerly winds are building wind slabs on north facing slopes. The storm snow rests on a mix of extensively wind affected surfaces at upper elevations or a thick layer of weak facets in sheltered areas. There is uncertainty as to whether this interface will persist as a reactive layer beyond the storm cycle. Recent avalanche activity in the Bear Pass area and snowpack tests results north of Terrace have indicated that this layer is still a concern. With more snow in the forecast later in the week, the reactivity of this layer will be important to track.
A crust from mid November lurks at the base of the snowpack. The last reported avalanche on this layer was Jan 17th, and it will most likely require a large trigger such as explosives or cornice fall to initiate this deep persistent slab problem.
