Pockets of wind slab may continue to be reactive to human triggers. Avalanche danger is trending down with each overnight freeze.
Weather Forecast
Overnight: Freezing levels down to 1300 metres by morning, with moderate northwest winds and the chance of a few flurries. Sunday: Mix of sun and cloud with light westerly winds and some convective flurries during the day and 8-10 cm in the evening. Monday: Re-freeze down to near valley bottoms, followed by light winds and cloudy skies with a chance of convective flurries. Tuesday: Good freeze followed by clear skies and light winds.
Avalanche Summary
No new avalanches reported. On Friday in the Elk Valley North area, there were numerous loose wet avalanches up to size 2.0 at all elevations on solar exposed aspects. The valley fog in the morning may have reduced the effects of the sun below treeline.
Snowpack Summary
On Friday, the sun was strong at higher elevations and the surface snow became moist or wet in the Elk Valley North. Castle Mountain reported 26 cm of new snow overnight, that I suspect must have settled rapidly due to the strong sun and high freezing levels. On Thursday in Crowsnest North, the sun was strong in the morning and solar aspects became moist up into the alpine. There was still some dry snow on north aspects in the alpine. The bottom third of the snowpack is composed of weak facets and full-depth avalanches over this basal weakness remain a concern, and may be triggered by large loads like cornice falls, or strong solar radiation on a clear day.
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.