Avalanche Forecast

High

Another sunny day forecasted for Saturday with freezing levels rising to around 2000m. Cloudy skies are expected to return either Saturday evening or Sunday morning, but the exact timing of this is uncertain.  If it's cloudy Saturday night, the hazard will increase on Sunday due to lack of "crust recovery". On Sunday, freezing levels rise sharply to as high as 2500m with possible flurries in the afternoon. The unstable weather continues into Monday. Generally light southerly ridgetop winds are forecasted throughout the period.

On Thursday, a skier triggered a size 2 slab avalanche on a north aspect at 2400m.  The weak layer buried in late February was the likely culprit of this avalanche.  Additionally, several naturally triggered size 2 slab avalanches were reported on a variety of aspects in the alpine. They generally started as smaller loose wet avalanches triggered by solar radiation that then stepped down to the persistent weak layer that was buried late February. Solar radiation and increasing freezing levels will be the main driver of natural avalanche activity in the coming days.

At ridgetop, cornices are huge and could become increasingly touchy with forecast solar radiation. Expect old wind slabs on lee features at treeline and in the alpine to become more reactive with solar radiation. Sunny skies have likely promoted a melt-freeze cycle on sun-exposed slopes. 60-110cm below the surface you'll find a persistent weak layer comprised of surface hoar, facets and/or a thick crust. This layer, which was buried in late February, seems variably reactive. In other words, it's still touchy in some places while in other places it's really tough to trigger, and there's not much of a reliable pattern telling us what exact aspects are most suspect. I'd continue to be suspicious of steep, unsupported features at treeline and in the alpine as this layer has the potential to produce very large avalanches. Below this interface, the snowpack is generally strong and well-settled.