A warming period and light rainfall have increased the likelihood of avalanche activity, and dangerous avalanche conditions continue.
Adopt terrain travel strategies that avoid steep areas on north-aspect terrain.
Past southerly winds and new snow has formed fresh wind slabs in alpine and treeline lee aspect terrain. Watch for changing conditions with aspect and elevation and avoid wind-loaded areas.
New weak cornice growth is a concern, it's very likely that even a small cornice collapse will initiate the building wind slab below.
Triggering persistent slab avalanches remains possible due to several weak layers in the top metre of the snowpack. Facet layers are the primary concern in alpine terrain, while preserved surface hoar layers are the concern in treeline terrain.
In the north of the region, the lower snowpack remains weak and heavily faceted. Large triggers such as cornice failure or smaller avalanches stepping down to this layer are possible.
Avalanches that start as wind slabs may step down to these deeper layers.
It is expected to warm with periods of clear sky. There is a recognized potential for possible small wet loose avalanches on specific steep solar aspects late in the day.
The past wind and snowfall have increased the size of cornices at the ridgetop. On the south aspect terrain, it's likely that cornice failures will initiate wind slabs found below.
Tuesday: Two very large (size 3) persistent weak-layer avalanches have been reported. One was naturally initiated, ran 400 m, and was suspected to have failed on a layer of surface hoar that was buried in early January. A vehicle initiated the second one remotely as it approached the slope. This avalanche failed to ground and ran on a bed surface of facets formed in November.
A recent large (size2) avalanche was observed near Hudson bay mountain and is suspected to be a windslab.
Monday: Two small (size 1.5) slab avalanches were initiated by ski cutting. The slab depths were between 20 and 50 cm at elevations between 1400 and 1500 m.
Sunday: A remotely triggered avalanche was reported by skiers near the 4 lakes in the Babine mountains provincial park. This avalanche was a small (size 1.5) slab avalanche and was initiated while traveling from below. See the embedded MIN for pictures and details.
On Saturday both vehicle and skier remotely triggered avalanches have been reported. These avalanches were large (size 1.5 to size 2.5) and found on north aspect terrain between 1500 and 1600 m. A naturally occurring avalanche was reported as very large (size 3) in the same vicinity of the remote trigger avalanches.
Warming temperatures and light rainfall have begun to settle the storm snow. This factor is likely to increase the sensitivity to triggers by riders. Avoid wind-loaded areas at upper elevations and keep in mind the potential for deeper instabilities to produce large and surprising avalanches.
Freezing levels reached nearly 2000 meters on Wednesday. This factor combined with light precipitation in the form of rain has settled and moistened the upper snowpack by roughly 10 cm.
At upper elevations, southerly winds continue to scour windward areas and redistributed past and current storm snow into wind slabs in lee areas. Wind slab depth has been reported as up to 50 cm in depth
Several persistent weak layers may be found in the top meter of the snowpack. Most prominently, a layer of surface hoar buried in early January is now 20-50 cm deep and is reactive to skier traffic. A weak layer of facets and/or surface hoar buried in late December is now down 70-110 cm.
In alpine terrain, triggering one of these layers is most likely on steep rocky slopes where they present as facets. In treeline terrain, the layers are most likely triggered on steep slopes in open trees where they present as preserved surface hoar.
In the north of the region, the lower-depth snowpack remains weak and heavily faceted.
Wednesday night
Mostly cloudy, with very light snowfall, trace amounts of accumulation. and no new snowfall is forecast. Alpine temperatures reach a high of 2 °C. Ridge wind west 55 km/h. Freezing level is near 2000 m descending to 1200 m .
Thursday
Cloudy and no new snowfall is forecast. Alpine temperatures 0°C. Ridge wind northwest 50 km/h. Freezing level 1200 m.
FridayClearing, no new snowfall is forecast. Alpine temperatures reach a high of -5 °C. Ridge wind northwest 30 km/h. Freezing level 500 m will descend to 0 m.
SaturdayClearing, no new snowfall is forecast. Alpine temperatures -20 °C. Ridge wind northeast 30 km/h. Freezing level 0 m.
More details can be found in the Mountain Weather Forecast.
