Colder conditions should help in the recovery of the lower elevation snowpack. Any significant day time warming, solar effect or rain will lead to a rapid deterioration in the snowpack stability - thereby raising the likelihood of wet slides.
Weather Forecast
Cooling temperatures overnight Saturday should help with a partial recovery of the lower elevation snowpack. Some snow above treeline is forecast for Sunday and Monday in the Icefields area.
Snowpack Summary
Warming and cooling cycle is creating a temperature crust on all aspects up to 2500m. Below this crust, a variety of layers exist with the weak basal facet layer being present in most areas at treeline and above. Any remaining snow on solar aspects below tree line has gone isothermal.
Avalanche Summary
The loose wet avalanche cycle that occurred on Friday has abated with field teams only observing two wet slides on northerly aspects to size 2. The size 3 slab on Mt. Saskatchewan that failed on the basal facet layer highlights the issue of this lingering deep persistent weakness.
Confidence
Timing of incoming weather systems is uncertain on Monday
Problems
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.
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.