Purcells

Freezing levels spike on Sunday which will increase the likelihood of large natural and human triggered avalanches. Avoid slopes with overhead exposure where falling cornices could trigger large avalanches.

Moderate - Freezing levels are uncertain

There's a fair bit of model disagreement but freezing levels are forecasted to spike to as high as 2600m on Sunday with cloudy skies and possible flurries overnight. Monday looks cloudy with lowering freezing levels. Tuesday should be clear and cool with freezing levels dropping sharply. Light to moderate southerly winds until Monday evening when they calm down.

On Friday, explosive control work inside a permanent closure at Kicking Horse Mountain Resort produced several size 2-3 slab avalanches which failed on both the mid and early February weak layers. This tells us that these weak layers are still alive and well even though they may be difficult to trigger in most areas. Small loose wet avalanches and failing cornices triggering slab avalanches on the late February layer would be on the forefront of my mind as I travel through the mountains this weekend.

At ridgetop, cornices are huge and could become increasingly touchy with rising freezing levels and solar radiation. Old wind slabs still linger on lee features at treeline and in the alpine which may become more reactive with solar radiation. 40-90cm below the surface you'll find a persistent weak layer comprised of surface hoar, facets and/or a thick crust. This layer seems variably reactive. In other words, it's still reactive to human triggers in some places while in other spots 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 large avalanches. Deeper weak layers from mid-February and early January are now down 50-90cm and 70-120cm respectively. Triggering an avalanche on either of these layers has become unlikely but still has the potential to produce very large avalanches in isolated locations with a heavy trigger or significant warming.