The snowpack is not to be trusted right now, especially if the sun pokes out. Surface instabilities and deeply buried weak layers have combined to create dangerous avalanche conditions.
Buried weak layers are most concerning at treeline elevations. Small slab avalanches may step down to this layer resulting in large, destructive avalanches.
New snow and wind continues to form reactive slabs over a layer of surface hoar buried early in the storm cycle, now 50-80 cm deep.
Bouts of sunshine on steep sun-exposed slopes could quickly initiate wet loose avalanche activity on Wednesday.
Operators in the Chilcotins continue to report new persistent slab avalanches running on our buried facet/crust interface, generally to size 2.5. On Monday, two such releases were remote triggered on north aspects from 150 m to 250 m away, one of them a size 3 (very large).
Several size 2 human-triggered avalanches were reported over the weekend. They occurred both within storm snow layers (40 to 60 cm deep) and on the persistent weak layer (100 cm deep).
Roughly 10-15 cm of new snow through Tuesday morning brought 4-day storm totals in the region to 40 to 60 cm, with alpine terrain heavily wind-affected. Storm snow covers a variety of layers including surface hoar in isolated shady areas.
A weak layer composed of weak faceted grains on a crust is now buried 80 to 150 cm deep. This layer remains sensitive to both human and natural triggers and continues to produce large, destructive avalanches.
The mid and lower snowpack below this layer is well-settled and strong.
Tuesday night
Cloudy with isolated flurries. 10 - 15 km/h southwest ridgetop wind. Freezing level to valley bottom.
Wednesday
A mix of sun and cloud. 10 km/h southwest or northwest ridgetop wind. Treeline temperature -2 °C with freezing level rising to 1500 m.
Thursday
Sunny. 10 km/h southwest or northwest ridgetop wind. Treeline temperature +4 °C with freezing level rising to 3200 m.
Friday
Sunny. 5 km/h variable ridgetop wind. Treeline temperature +9 with freezing level to 3400 m.
More details can be found in the Mountain Weather Forecast.
