A weak layer is present at the ideal depth for large rider triggered avalanches.
The safest way to manage this problem is through conservative terrain choices.
A weak layer of surface hoar is down 70-100 cm. This is a prime depth for rider triggering. To manage this problem, stick to conservative terrain, with a deeper snowpack and slopes that have seen significant skier traffic. Below 2100m this layer is bridged by a supportive rain crust.
Loose surface snow is easily triggered in steep terrain. Fresh storm snow will increase the size of these avalanches. Use caution, even small sluff can push you into dangerous terrain.
Expect fresh storm slabs building on Thursday. Watch for reactive slabs on lee features in the alpine and at treeline. This problem may be more likely to trigger in sheltered areas where surface hoar is present beneath the slab.
Natural avalanches are possible later in the day Thursday with an incoming storm forecast.
On Wednesday, no new natural avalanches were observed along the highway corridor.
On Tuesday, a group triggered a size 2.5 on Ursus Minor. This avalanche was triggered in a wind loaded pocket near ridge top, in a generally shallow faceted snowpack. Wide, impressive propagation occurred on the Dec 1 surface hoar, facet layer.
Storm snow Thursday will start to bury a new surface hoar layer, which sits on top a thin sun crust in steep terrain.
A rain crust down 30cm is present up to 2100m.
A weak layer (Dec 1 surface hoar) buried 70-100cm deep continues to produce 'sudden' results in snowpack tests and human triggered avalanches. The surface hoar sits on a sun crust on solar aspects at upper elevations.
The base of the snowpack is facetted at upper elevations.
A weak front sweeps across the province giving light snow and dropping freezing levels on Thursday.
Thursday: Snow 10cm with light SW winds, High: -5 °C, Freezing level 1600m.
Friday: Isolated flurries, High: -2 °C, light SW winds, freezing level 1700m.
Saturday: Cloudy with sunny periods, High: -3°C, light SW winds, freezing level 1500m.
