Uncertainty around buried weak layers is best managed with conservative terrain choices.
Recent strong southerly winds have likely formed wind slabs on a variety of aspects on lee features in exposed terrain at treeline and above.
Buried surface hoar may remain rider-triggerable. This layer is of greatest concern around treeline elevation in areas where a significant crust is not found above it.
There have been very few reports from this region in the past few days.
Last weekend, there were numerous reports of natural and skier-triggered persistent slabs, mainly at treeline, up to size 2. Check out this MIN from Powder King on Saturday and this MIN in Torpy on Friday. We suspect these avalanches ran on one of the surface hoar layers in the top meter of the snowpack.
Natural avalanche activity is expected to trend down, but large human-triggered slabs remain possible.
Recent winds have resulted in extensive wind-affected surfaces in the alpine and treeline. Below treeline, a fresh crust has formed either on or close to the surface.
The mid pack contains several layers of note; a layer of surface hoar down 30 to 50 cm, a significant crust from the early December rain event down around 60 cm and a layer of surface hoar down 70 to 120 cm.
Snowpack depth throughout this region is highly variable and as a result the depths of the above mentioned layers are approximate and could be different than what you find in your riding area.
Thursday Night
A mix of sun and cloud, no new snow. South alpine wind 50 to 70 km/h. Treeline temperature -1 °C. Freezing level 1400 m. Possible temperature inversion.
Friday
Partially cloudy, no new snow. South alpine wind 40 to 50 km/h. Treeline temperature 3 °C. Freezing level 2500 m. Possible temperature inversion.
Saturday
Mainly cloudy, no new snow. South alpine wind, 20 to 40 km/h. Treeline temperature 1 °C. Freezing level 2000 m. Possible temperature inversion.
Sunday
Cloudy, snow flurries 1-5 cm. South alpine wind, 20 to 40 km/h. Treeline temperature -5 °C. Freezing level 1000 m.
More details can be found in the Mountain Weather Forecast.
