Avalanche danger will increase over the day as new snow and strong winds form reactive slabs over a weak snow surface. Approach wind loaded features with caution.
Weak faceted grains above the early December crust continue to produce unpredictable results. Large destructive avalanches have been produced on this layer recently. This layer is found around 80 to 150 cm deep and is most common at elevations between 1700 m and 2200 m. Read more about it here.
Storm slabs will build with continued snowfall over the day. Strong south/southwest winds will create deeper deposits in wind loaded features, use caution approaching ridge crest and cross loaded features.
Reactive slabs are expected as new snow falls over weak crystals and wind effected surfaces. Larger avalanches could be triggered in the treeline where wind slab has formed over surface hoar.
An active front shifts south bringing moderate snowfall with very strong winds.
SATURDAY NIGHT: Continued light snowfall, 5-10cm with strong to extreme southwest winds.
SUNDAY: Moderate southeast winds increase over the day to strong southerlies. 10-20cm possible over the day. Alpine high of -15.
MONDAY: Up to 10cm of snow, tapering off in the afternoon. Alpine high of -10 with light southerly winds.
TUESDAY: Chance of flurries with light southeast winds. Alpine high of -15.
Persistent slab avalanches were produced by explosive control work yesterday up to size 3. These slabs failed on the early December crust/facet interface up to 100cm deep. Several large and destructive avalanches have been naturally and skier triggered in the over the last week up to size 3. Each had wide propagation and ran several hundred metres. The avalanches were up to 150cm deep and were triggered in a rocky and thin area. This layer is still extremely concerning and will likely be for most of the season.
In the past 3 days, several wind slabs up to size 2 have been triggered by riders on northerly and southerly aspects at treeline and above. Several natural cornice failures were also observed on all aspects. Cornices are able to effect deeply buried weak layers, navigate around them (on ridgelines, and on slopes below them) with care.
We'd appreciate if you submit your observations to the Mountain Information Network, even just a photo.
New snowfall and wind continues to redistribute recent snow into deeper deposits on north and east aspects at treeline and above. These new slabs will form over faceted and wind effected surfaces, creating a poor bond and reactive slabs.
A layer of weak surface hoar crystals can be found 30-50cm deep in sheltered terrain features at alpine and treeline elevations, and in open features like cut blocks below treeline. Although avalanche activity hasn't been prominent on this layer, it has been reactive in snowpack tests.
The crust formed by the early December rain event sits 100-150cm deep and is found up to 2200m in the North Columbia's. Weak and faceted grains sit above, creating a weak interface that is still reactive to human triggers. This layer is most reactive at treeline, and in areas where the snowpack thins and the weak interface is much closer to the surface. This layer has the potential to produce large and destructive avalanches if triggered. Recent activity in the North Columbia's has been limited to explosive triggers - however the southern Selkirks have seen significant skier triggered activity on this layer to size 3.5.
