Weather Forecast
Synopsis: A ridge of high pressure over the BC interior should maintain dry conditions and a mix of sun and cloud for at least the next few days. Winds are generally light from the south. Temperatures gradually rise over the next few days. By Wednesday the freezing level should be around 1800-2000 m.
Avalanche Summary
Natural avalanches, cornice falls, and skier controlled avalanches were reported up to size 2.0 that did not release below the storm snow. Expect loose moist snow to fall naturally from steep terrain and cliff bands that may trigger the storm snow where it is moist and sitting on a previous crust.
Snowpack Summary
Moist snow can be found on solar aspects up to about tree-line. Cold clear nights are expected to develop new melt/freeze crusts in areas that became moist. There is close to a metre of storm snow that has fallen in the last few days. This storm slab is sitting above variable surfaces that include crusts and moist layers that were deposited during the wet (Pineapple Express) storm last week. Periods of strong winds in the alpine transported the storm snow into thick pockets of wind slab that may take several days to settle and bond to the old surface. Cornice growth has been reported to be extensive and weakly bonded. Natural cornice falls are a concern, especially if we see periods of strong solar radiation. Cornice falls or storm slabs in motion may step down to the weak layer of buried surface hoar from March 10th.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
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.