Avalanche Forecast

Fair - Freezing levels are uncertain on Saturday

Friday night: 15-20cm snow (locally more is possible on western slopes). Strong south-westerly winds. Alpine temperatures rising to -10C.Saturday: 15-20cm snow. Strong south-westerly winds. Alpine temperatures rising to -4C in the morning. Sunday: Light snow. Cooler temperatures. Moderate westerly winds. Monday: Light snow. Moderate to strong westerlies.

Several natural and human-triggered avalanches have been reported over the last few days. A wind event on Tuesday triggered slabs on exposed lee slopes. On Wednesday, skiers triggered size 1.5 slabs below treeline and observed natural and cornice-triggered events up to size2, mainly on north and east aspects in the alpine. Recent avalanches have mainly been running in, or at the base of, the storm snow. Avalanche activity was slowing down by the end of the week, but will increase this weekend with the incoming storm.

New snow and wind are creating soft new wind slabs lee to the south-west. Harder, old buried wind slabs also exist in the alpine. By Saturday morning, I expect storm slabs and wind slabs to be widespread due to the combination of heavy new snow, wind and warming landing on dry loose snow. Various surfaces buried in early January including a rain crust, spotty surface hoar and preserved stellar snow crystals are now about 80-100cm deep and may provide a sliding layer for storm-related avalanches over the weekend. A surface hoar layer buried in mid-December is gaining strength, but professionals are still treating it with caution, as the consequences of an avalanche on this layer would be high. Occasional hard, planar results have been reported on this layer in snowpack tests. It's now down about 140cm in the snowpack.