Regions
Banff Yoho Kootenay.
The sun will pack a punch at all elevations, be weary that solar inputs can affect deep instabilities at higher elevations and deteriorate the snowpack structure below treeline.
Weather Forecast
A diurnal weather pattern is forecasted for Sunday, Monday with daytime highs at valley bottom approaching 10 degrees and lows below freezing. Expect short convective pulses bringing in snow and rain, with mostly clear skies Sunday.
Snowpack Summary
Dense, rounded snow comprises the upper half of the snowpack and sits on a very weak base of depth hoar. This unstable structure produces consistent, sudden collapse test results in the lower snowpack. Wind slab continues to developer at tree line and above. Below treeline a melt freeze cycle is developing, with the snowpack weakening in PM.
Avalanche Summary
The natural activity has decreased over the last few days however daily reports of activity continue to come in, Na size 3 observed on 93S in the Numa falls area suspect cornice trigger today. It appears to take only very small inputs of sun, wind or precip to trigger natural events and artificial / human triggering should be considered likely.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.