Extensive wind loading has occurred and slopes appear primed for human triggering at treeline and above. Conservative terrain choices are crucial. Good skiing in protected areas below treeline.
Multiple vintages of wind slab can be found in the upper 100cm of the snowpack due to persistent wind and snowfall for the past week. Many areas look significantly loaded and primed for human triggering.
Avalanches initiated in the surface wind slab will likely trigger this deeper instability. Large and destructive avalanches are possible.
One size 2.5 persistent slab was observed in the Burstall Pass area today. The avalanche looked to be about 24hrs old and exhibited very wide propagation (250m), but did not run far down slope. The slide was also very deep in some parts of the crown, ranging from 100 to 300cm deep.
The snow keeps coming! Another 10cm in the past 24hrs, brings recent storm snow up to as much as 90cm. Wind slabs are widespread in the alpine and on lee and cross-loaded features at treeline. These wind slabs are likely to be sensitive to skier traffic. The December 16th crust is down about 75cm, but isn't producing shears. The November crust is now down 100-150cm, and is showing signs of faceting. Any avalanche triggered in the upper snowpack has a strong likelihood to step down to deeper instabilities.
Tuesday will be cloudy with temps near -7C for a high. Snowfall amounts are expected to be in the 5-10cm range. Unfortunately the winds will be out of the SW at 100km/h to start the day, and then decrease somewhat by midday.
More details can be found in the Mountain Weather Forecast.
