South Columbia

Thin new wind slabs are expected to be touchy on Monday. Use extra caution in wind exposed terrain and watch for signs of recent wind loading in leeward and cross-loaded terrain features.

Moderate - Wind effect is extremely variable

A few centimetres of new snow is expected Sunday night before an Arctic front moves southwards on Monday bringing a return to cold and dry conditions which is expected to persist for most of the week. A mix of sun and cloud is expected on Monday with treeline temperatures around -10C. Alpine wind is forecast to be moderate to strong from northwest in the morning and ease off in the afternoon. Mostly sunny conditions are forecast for Tuesday and Wednesday with light alpine wind from the northeast and treeline temperatures around -15C.

On Saturday, a natural size 2 wind slab avalanche was observed on a northwest aspect at 2200 m elevation in the Monashees. Skiers also triggered three size 1-1.5 wind slab avalanches on north, northeast, and southeast aspects at 2000-2300 m elevation in the Monashees. One of these was remotely triggered from 20 m away. The typical slab thickness in these avalanches was 10-15 cm. Ongoing moderate to strong wind with small amounts of new snow on Sunday night is expected to continue to develop touchy new winds slabs. Recent wind has been from variety of aspects and wind slabs should be expected on all aspects.

20-50 cm of old snow has settled over the mid-January interface which consists of buried surface hoar in sheltered areas, sun crust on south aspects, and/or widespread faceted old snow. The interface has generally stabilized but isolated weaknesses may still exist where buried surface hoar is preserved. Ongoing moderate to strong winds in exposed terrain have been forming new wind slabs over the weekend. The new snow and strong winds on Sunday night are expected to add additional load to these touchy wind slabs. The mid-December surface hoar/facet persistent weakness may be found down 70-120 cm and is generally considered dormant. However, we are still receiving occasional reports of sudden results in snowpack tests, suggesting that it has to potential to propagate into a large avalanche if triggered; watch shallow snowpack areas where the layer is closer to the snow surface.