News » Whistler

Backcountry Avalanche Advisory


As of Wednesday, March 25, 7:20 a.m.

Alpine: Considerable Thursday, Moderate Friday

Treeline: Moderate through Friday

Below Treeline: Moderate through Friday

Travel Advisory: Wind loaded soft slabs are sitting over variable surfaces in the alpine and treeline. Caution is advised around any previously shallow rocky areas that are now loaded with storm snow. Although cooling temperatures have tightened up the snowpack, we have seen widespread natural and skier-triggered deep slab avalanches stepping down to the December facets. Remember that sun warming may make the snowpack more fluid and ready to react. Give cornices a wide berth as cornices have triggered many of the recent large avalanches.

Avalanche Activity: Widespread natural avalanche activity with dozens of deep size 3 slabs, and even a size 4, ran over the weekend. Triggers for this cycle ranged from naturals and cornice failures to skier-remote and explosives-triggered avalanches. This avalanche activity has settled down since Monday. The deeper releases were all between 1,700 metres and 2,300 metres on all aspects. One fracture line profile at 1,775 metres on a NE aspect showed the bed surface to be surface hoar on a crust. Most large avalanches in the alpine appeared to involve the Dec. 6 facet layer.

Snowpack: Wind-loaded snow is sitting on a variety of surfaces in the alpine and treeline. There continue to be several persistent weak layers in the snowpack. Stepped fracture lines would indicate that the weaknesses from December, February and March are all at or near their threshold. Stability tests in profiles are indicating hard shears, but the widespread, easily triggered large avalanche activity indicates a more acute weakness. As always, the areas to avoid are those where the snowpack is shallow and the weak basal layers are more extensive.

Weather: Unsettled conditions as a series of weak fronts brush the south coast. We can expect light snowfall, moderate winds and cool temperatures until a break for Wed/Thurs.

Travel with a partner and be equipped and prepared for self-rescue. Watch out for winch-cats or snowmobile traffic if you re-enter the area after operating hours.

Surf to or for daily updates.