Regions
Banff Yoho Kootenay.
The temperature inversion continues with very warm alpine temperatures on Saturday and Sunday. Ice climbers in particular should expect solar triggered snowballing and sluffing out of steep rocky South facing terrain during the heat of the day.
Weather Forecast
Clear conditions with light winds and very warm alpine temperatures are forecast for Saturday with alpine temperatures remaining near freezing for Saturday night. In sheltered sunny locations temperatures will get well above freezing during the middle of the day. A temperature inversion will keep the valley bottoms cool.
Snowpack Summary
Sun crust forming on sheltered solar aspects. Below treeline the snowpack has set up well and is slowly facetting. In open areas at tree line and above there are numerous wind slabs of varying depth. Isolated wind slabs over facets typical of the Rockies can still be expected in thin areas.
Avalanche Summary
Some small solar triggered sluffs to size 1 observed on Friday. One older size 3 natural avalanche was also observed on the White Pyramid Glacier. This appears to have slid during the last major wind event a few days ago. In places it stepped down to glacier ice showing that on high North aspects there can be a basal weak layer to keep in mind.
Confidence
Due to the number of field observations
Problems
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.
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.