Tiny Tim and the Ghost of Christmas Past found good turns on Hilda Ridge, Merry Christmas one and all.
Weather Forecast
No significant snowfall is forecast until the weekend when up to 10cm may arrive in the Icefields area. Temperatures will drop over Christmas with overnight lows in the low teens but warming during the day. Over the next 24 hours winds will remain light from the West and at upper elevations NW. Over the weekend these are forecast to increase.
Snowpack Summary
Wind slab forming on lee alpine ridge lines. Large surface hoar crystals formed last week are being buried by new snow. This layer is more likely to be found on sheltered slopes at tree line and below. The interface between the strong mid-pack and weaker basal facets is most susceptible to human triggering from shallow rocky areas.
Avalanche Summary
Three new avalanches were recorded in the Columbia Icefields area. The events were size 2 thin storm slabs and class 1.5 point releases from steep slab alpine terrain.
Confidence
The weather pattern is stable
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.