News » Whistler

Backcountry Advisory

"Within the ski area we saw slopes run that have not slid in 10 years."

comment

As of Wednesday, March 1, 2006

Alpine: CONSIDERABLE

Treeline: CONSIDERABLE

Below Treeline: CONSIDERABLE

Travel Advisory: Extended periods of 100 km/h winds and fluctuating freezing levels have loaded a variable mix of soft slabs, stiff upside down windslabs and scoured old snow in their wake.

Avalanche Activity: Slab avalanches up to 80 cm deep were releasing with the weight of a skier within the ski area over the past two days. A natural avalanche cycle occurred early in the storm and those start zones have reloaded since then. Within the ski area we saw slopes run that have not slid in 10 years.

Snowpack: Prior to the recent storm cycle we had a variety of windslabs and temperature crusts that were sitting on small facet crystals. Below these surface layers the snowpack was rather well settled. Stability tests of these surface layers were producing variable results, including sudden collapse and sudden planar shears. Surface hoar was also still found in isolated areas, but was not reactive to testing. The storm snow accumulated rapidly on Saturday night while 100 km/h winds and warm temperatures moved it all around on Monday.

The pre-storm layers are now covered by areas of 20 cm soft slab, upside down windslab and areas of deep slab in sheltered lee terrain. The areas of deep slab have been reactive to skier triggering while the soft slabs have been producing slow hard shears where tested. The warming produced thin temperature crusts within the storm snow up to 1,800 metres. On Wednesday morning the storm snow was still settling rapidly.

Weather:  Unsettled conditions are expected for our area for the next few days with moderate alpine winds and low freezing levels. There is a slight chance of light precipitation as well.

Check avalanche.ca for daily bulletin updates.

Add a comment