Regions
Northwest Coastal.
Confidence
Fair - Intensity of incoming weather is uncertain
Weather Forecast
A series of systems will be crossing the Southern part of the province through the forecast period. Most of the punch will be in the South, leaving the North West with light- moderate precipitation amounts, a dominating SW flow, and above normal temperatures. Tuesday: Snow amounts 2-5 cm. Ridgetop winds moderate from the SE. Freezing levels 1100-1300 m. Wednesday/ Thursday: Moderate snow amounts in the West, lighter accumulations inland. Ridgetop winds strong from the South. Freezing levels near 1000 m, falling to valley bottom Wednesday overnight.
Avalanche Summary
No recent avalanche activity has been reported. On Sunday natural cornice failures triggered slab avalanches up to size 2.5 on the slopes below. Forecast snow may have a poor bond to underlying crusts, pay attention to the weather conditions in your local mountains, and make observations while you travel.
Snowpack Summary
Moderate to strong southeast winds have created wind slabs on opposite slopes, and terrain features in the alpine, and treeline. Crusts have formed on solar aspects at all elevations. They become moist under sunny skies during the day with a good crust recovery at night. Melt-freeze conditions exist below treeline. Forecast snow may have a poor bond to these crusts. Below this down 60-120 cm exists a surface hoar or facets interface. There has been no recent activity on these layers but they could wake up with heavy triggers like a large cornice fall, or under the weight of a sled and it's rider. Cornices in the region are reported to be very large and potentially unstable.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.