Regions
Northwest Coastal.
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain on Saturday
Weather Forecast
Saturday: Light to moderate snowfall occurring late in the day / Moderate southwest winds / Freezing level at 800mSunday: Light snowfall / Moderate southwest winds / Freezing level at 500mMonday: Trace amounts of new snow / Light west winds / Freezing level at 400m
Avalanche Summary
Cornice falls to size 3 have been reported from various parts of the region, which likely occurred in response to strong daily temperature fluctuations. In the north of the region cornice fall triggered slabs, one of which failed at ground level.
Snowpack Summary
Strong winds winds from earlier in the week have created hard wind slabs in exposed lee terrain; however, over the past few days these have likely gained considerable strength. In sheltered areas the snow surface consists of facets or surface hoar. A sun crust or moist snow exists on south facing slopes, depending on the time of day. Watch out for cornices, as they are large and fragile. The mid snowpack layers are generally well settled and strong. Facets at the base of the snowpack may resurface as a concern now that spring warming is on the doorstep and full-depth releases are becoming more likely (primarily in the northern part of the region).
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.