Avalanche Forecast

Moderate - Uncertainty is due to the timing, track, & intensity of the incoming weather system. Uncertainty is due to whether buried persistent weak layers become active, triggering avalanches, with the arrival of the forecast weather.

Thursday night: Cloudy, up to 5 cm new snow, light to moderate southwest winds, freezing level 1300 m.

Friday: Mostly cloudy, 5-10 cm of snow above 1200 m, southwest winds increasing to strong by end of day.

Saturday: Cloudy, 15-25 cm new snow, southwest winds decreasing from strong to light by end of day, freezing level dropping below 1000 m.

Sunday: Mostly clear, light variable winds, freezing level 1000 m.

No new avalanche observations. This MIN post from Monday reports a skier triggered size 1 wind slab in the alpine, suspected to have run on surface hoar. Explosive control work conducted Monday produced size 1-1.5 storm slabs running on a crust.

By Friday afternoon, 5-15 cm of snow is forecast to accumulate. Strong winds from the southwest will likely drift the new snow into touchy wind slabs on lee features at upper elevations and may bring cornices to their breaking point.

30-60 cm of recent snow sits over a layer of surface hoar on north-facing aspects. Surface hoar is an exceptionally weak layer not often seen in this region. There may also be areas where the buried surface hoar sits on a sun crust, which makes an excellent bed surface for avalanches. 

The remainder of the snowpack is well settled. Depth varies from around 250 to 300 cm at the peaks of the North Shore mountains (1400 m), tapering rapidly with elevation. Little snow exists below 1000 m.

• Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
• Be aware of the potential for large avalanches due to the presence of buried surface hoar.
• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.