Avalanche Forecast

Poor - Timing or intensity of solar radiation is uncertain

Sunday: Sunny. Freezing level near 2300m. Light winds.Monday/Tuesday: Cloud and light precipitation. Temperatures staying mild. Freezing level near 2000m. Light winds.

Loose solar-triggered avalanches were observed on Friday and a very large (up to 10 m high) cornice collapsed at 2400 m on a NE aspect in the Monashees. On Thursday, a very large avalanche (size 3) ran naturally on a south aspect all the way to valley bottom and part-way up the other side. On Wednesday, a size 3 slab failed on the mid-Feb weakness on a west aspect, with a 2 m deep crown. It was suspected that solar warming was the trigger. While avalanche activity on this layer is no longer widespread, large avalanches continue to occur on a sporadic basis. Last weekend, size 3-3.5 slabs, 100-180 cm deep, failed naturally and two size 3 avalanches were triggered accidentally by snowmobilers just south of the region near Kimberley. Solar warming may lead to another spike in deep persistent slab activity over the next couple of days.

Wind slabs in the alpine and at treeline are becoming less reactive. A melt-freeze crust exists from valley floor into the alpine on solar aspects. A key concern is a persistent weak layer of buried surface hoar from mid-February that is buried 1-2 m deep. Snowpack tests give sudden "pops" results on this layer in some areas, indicating the ongoing potential for very large avalanches. Because the layer is so deeply buried, it's unlikely to fail without a large trigger (e.g. cornice fall or explosive). However, there's always the chance of someone stumbling across a sweet spot, particularly in shallow snowpack areas. Solar warming could also destabilize the overlying snowpack, with the potential for step-downs or cornice triggering on this layer.