New snow, strong winds, and rising temperatures are a perfect recipe for avalanches. Careful route selection will be critical for safe back country travel
Confidence
Fair - Forecast snowfall amounts are uncertain
Weather Forecast
The South Coast Inland should see some clearing on Friday with freezing levels going up to 2700m. On Saturday expect 10mm of moisture with freezing levels at around 1700m followed by another 5 to 10mm on Sunday and Monday next week with freezing levels dropping to more normal seasonal values.
Avalanche Summary
A few wet snow avalanches have been reported occurring on solar aspects. Cloudy skies may keep the surface from overnight freezing and rising teemperatures may increase the likelihood of loose wet avalanches and cornice failures.
Snowpack Summary
The recent precipitation is falling on a variety of old snow surfaces that exist throughout the region. Melt-freeze conditions can be found on solar aspects in the alpine, and on all aspects at lower elevations. On high north-facing terrain, you may find stubborn old wind slabs and some surface facets from cold, clear nights, buried around March 5th. The snowpack is generally strong and well settled. Cornices , however, may become weak with daytime warming. New storm snow will most likely be quite wet and accompanied by strong SW winds.
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.
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.