Winds are expected to increase. If you see blowing snow, expect to find fresh wind slabs.
Sticking to conservative terrain selection is your best defence against buried weak layers.
Increasing winds will quickly impact loose snow. Watch for blowing snow and check for reactive pockets under ridgelines and steep rolls.
Recent large avalanches have failed on weak grains over a buried crust. This weak layer has shown wide propagation across large terrain features.
On Friday, explosives triggered several small size 1-1.5 wind slab avalanches, with crowns 20-40 cm deep.
Thursday and Friday, natural and rider-triggered wind slab avalanches to size 2 were reported.
A persistent weak layer recently produced very large natural and human-triggered avalanches, including remote-triggering up to 1 km away. On Dec 28th this near miss surprised riders, and this MIN describes avalanches triggered from valley bottom.
5 to 15 cm of recent snow covers older wind-affected snow. Easterly winds have reverse-loaded features and wind slabs can be found on various aspects. Soft snow still exists in sheltered terrain and in the trees.
Our primary concern is a persistent weak layer of surface hoar and facets overlying a crust. It is buried 50 to 100 cm deep in the southern parts of the region and up to 200 cm deep in areas north of Stewart. Several recent large avalanches have failed on this layer producing wide propagation.
The lower snowpack is well settled, with no deeper layers of concern. Treeline snow depths are around 160 cm.
Sunday night
Mostly cloudy. 20 to 30 km/h west ridgetop wind. Treeline temperature -5 °C.
Monday
Sunny. 30 to 70 km/h southwest ridgetop wind. Treeline temperature -4 °C.
Tuesday
Cloudy with flurries, up to 20 cm. 40 to 80 km/h southwest ridgetop wind. Treeline temperature -3 °C.
Wednesday
Overnight flurries, 15 to 40 cm snow by morning. 15 to 30 km/h southwest ridgetop wind. Treeline temperature -6°C.
More details can be found in the Mountain Weather Forecast.
