Wind slabs remain triggerable at upper elevations.
Verify conditions as you travel and back off if you notice signs of instability.
Wind slabs have been reactive in the region. The most likely areas for triggering will be steep and convex leeward slopes at upper elevations, or where recent snow covers surface hoar.
Use extra caution in areas with a thin, uniform snowpack (less than 100 cm). These areas are inherently weak, with heavily faceted snow and crusts closer to the surface, making them easier to trigger.
On Wednesday, a size 1 wind slab was triggered accidentally by a skier on a northwest-facing treeline slope. A size 2 naturally triggered wind slab occurrent on the same aspect but in the alpine.
On Monday & Tuesday, several natural and human-triggered slab avalanches up to size 2 were reported. These occurred on a variety of aspects and elevation zones.
Looking forward: We expect wind slabs to remain triggerable on Friday, especially where they overlie surface hoar.
Up to 30 cm of recently accumulated storm snow covers a variety of old surfaces, including surface hoar in wind-sheltered terrain, and a sun crust on steep south-facing slopes.
In the mid-snowpack, a melt-freeze crust exists that was buried in mid-December. This layer is most prevalent at treeline elevations and below.
The lower snowpack consists of a thick melt-freeze crust, with weak faceted snow and/or depth hoar near the ground.
Snow depths vary widely across the region, averaging roughly 100 to 200 cm at treeline.
Thursday Night
Mostly clear skies. 40 km/h west ridgetop wind. Treeline temperature -11 °C.
Friday
Mix of sun and clouds. 40 km/h west ridgetop wind. Treeline temperature -6 °C.
Saturday
Sunny. 30 km/h west ridgetop wind. Treeline temperature 0 °C. Freezing level rising to 2000 m in the PM.
Sunday
Cloudy. 0 to 2 cm of snow. 40 km/h west ridgetop wind. Treeline temperature -4 °C.
More details can be found in the Mountain Weather Forecast.
