Careful terrain and route selection are needed with all the new snow and strong winds.
Confidence
Fair - Due to the number and quality of field observations
Weather Forecast
This Pacific cold front should pass through the South Coast Inland and head east towards the Columbias by late Saturday afternoon followed by a brief break in the weather early Sunday. Sunday afternoon will see another "pulse" of moisture, although less intense than the last one and may leave 10-15cm of snow at elevations above 1000m. Moderate to strong winds above 1500m will accompany this system.
Avalanche Summary
A few natural slabs have been reported that are supected to have occurred in the past 24 hrs, most likely during the height of the recent wind, snow, and warm temperature event. Also a natural size 2 initiated by a cornice failure , 20 to 30cm thick, and running on an old sruct. A few wet snow avalanches have been reported occurring on solar aspects. Cloudy skies may keep the surface from overnight freezing and rising temperatures may increase the likelihood of loose wet avalanches and cornice failures.
Snowpack Summary
Incoming precipitation will fall on a variety of old snow surfaces that exist throughout the region. There are numerous crusts and old wind slabs buried in the snowpack above treeline that may still be problematic but below treeline the snowpack has had numerous warming and rain events and should be bombproof for the most part. Rain has recently been reported to ridge tops in the Coquihalla region. Solar aspects are reported to be going isothermal in some areas below 1600m
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.
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.