Regions
Northwest Coastal.
Confidence
Fair - Forecast snowfall amounts are uncertain
Weather Forecast
Wednesday: Light convective snowfall - 5-15cm. The freezing level rises to 400-500m during the day. Winds are moderate from the SW. Thursday: Isolated flurries with possible sunny breaks in the afternoon. Freezing level rising to 600m. Winds are light from the SE. Friday: A mix of sun and cloud. Freezing level rising to 600-800m during the day.
Avalanche Summary
There has been very little recent avalanche activity aside from a few cornice failures, most of which did not trigger a slab below. Expect to find small pockets of wind slab in steep exposed terrain that could be triggered.
Snowpack Summary
5-15cm of new snow sits on the previous snow surface which included a sun crust on southerly aspects, surface facets or surface hoar in cool shady areas, and pockets of wind slab in exposed terrain. A variety of potential weak layers exist between 60 and 120cm deep. These include surface hoar or facets. There has been no recent activity on these layers but they could wake up with heavy triggers like a large cornice chunk or a snowmobile digging its track in. Cornices in the region are reported to be very large and potentially unstable.
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.