Confidence
Fair - Due to variable snowpack conditions
Weather Forecast
A firmly embedded ridge of high pressure in Alberta seems to be causing systems to fizzle once they reach the Columbia Mountains. On Friday light snowfall is expected but should taper-off with only trace amounts forecast for Saturday/Sunday. Winds should be light and west/northwesterly throughout the period with freezing levels peaking at about 1300m.
Avalanche Summary
No new avalanches to report. Our image gallery now has photos from the recent Hellroaring Creek avalanche near Kimberley. Follow the link to view: https://avalanche.ca/cac/library/avalanche-image-galleries/avalanches-2011-2012
Snowpack Summary
Cooling has helped the snowpack to gain considerable strength since the warming on the weekend and a crusts have now developed on slopes that saw direct sun. On shaded aspects the upper snowpack is also well settled. The exception to this may be isolated windslabs due to redistribution of surface snow on Monday and Tuesday. Below this sits a fairly well bonded mid-pack and riders are feeling increasingly confident in steeper terrain, particularly in areas with a deeper snowpack. In the south of the region, it is thought that the January 13th surface hoar (buried about 40cm down) may still be reactive. There are also basal facets at the ground which were reactive with the warming last weekend, especially in thin snowpack parts of the region. Snowpack depths at 2000m sit near 2m deep. If you're traveling around the mountains, it's a good time to take notice of what layers are developing (surface hoar/ crusts/ facets) that may become an issue once buried.
Problems
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.
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.