South Columbia

Tricky conditions persist in the alpine with fresh wind slabs and the continuing possibility of avalanches releasing on deep weak layers. Conservative terrain selection remains highly recommended.

Moderate -

On Friday, 10-15 cm of new snow is expected with moderate to strong alpine wind from the southwest and freezing levels reaching around 1500 m. Another 5-10 cm is expected on Saturday with moderate alpine wind from the southwest and freezing levels around 1500 m in the afternoon. Mainly dry and sunny conditions are forecast for Sunday with light alpine wind and afternoon freezing levels reaching upwards of 1800 m.

On Wednesday, a natural size 2 was reported on a south aspect. A skier triggered a size 1 storm slab on a north aspect at 2200 m which was 15-25 cm thick. Explosives triggered a size 2 storm slab on a northeast aspect at 2300 m which was 30-40 cm thick. On Tuesday, a ski cut triggered a thin size 1 storm slab on a north aspect at 2000 m. Explosives triggered a size 2.5 cornice which cleaned out the slope below. On Monday, four natural size 2.5-3 wind slabs were observed on southeast and east aspects at 2250-2400 m. Explosives triggered a deep persistent slab on a northeast aspect that released up to 2 m deep. Over the weekend, a widespread avalanche cycle occurred with avalanches up to size 4.5. This included very large cornice releases, avalanches releasing on layers near the base of the snowpack, propagations over 1 km wide, and mature timber being broken. Click here for photos of the recent avalanches.On Friday, wind slabs and cornice are expected to be reactive at higher elevations. We are in a low probability, high consequence scenario for persistent slab avalanches failing on buried weak layers. Click here for more details.

15-25 cm of new snow overlies a thick rain crust which formed over the weekend. The crust has been reported as high as 2000 m and has been reported to be supportive to skiers between 1500 and 1900 m. Alpine wind has recently been strong from a variety of directions and wind slabs are expected on all aspects in wind exposed terrain. Large cornices are also reported on northerly aspects in the alpine. The rain crust which formed last week is now down 40-50 cm and generally seems to be well bonded to the surrounding snow. The February weak layers are down 100-150 cm and woke up during the recent storm cycle with many avalanches stepping down. The deep mid-December facet layer and November rain crust both still linger near the bottom of the snowpack and a few avalanches and cornice falls have stepped down to these layers recently resulting in very large avalanches.