A general cooling trend is expected through the weekend. The avalanche danger will rise rapidly if temperatures warm to above freezing and there is any significant solar radiation. Spring like conditions below treeline.
Weather Forecast
Temperatures and freezing levels will fall from the heat on Friday through the weekend. Expect some light precipitation overnight on Friday then skies clear Saturday afternoon. Clouds return on Sunday with up to 15 cm possible Sunday afternoon into Monday. Moderate to strong winds expected to continue.
Snowpack Summary
Warm temps on Friday and cooling through the weekend will create a temperature crust on all aspects up to 2500m. Below this crust, a variety of layers and crusts exist with local variations thoughout the forecast area. A weak basal facet layer is present in most areas at treeline and above.
Avalanche Summary
A loose wet avalanche cycle occurred Friday afternoon primarily at treeline on easterly aspects up to size 2. Of note was a large size 3 slab on Mt. Saskatchewan on a steep NE facing alpine slope likely on the basal facet layer.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Sunday
Problems
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.