Regions
Northwest Coastal.
New snow and strong winds continue to develop storm slabs resulting in High avalanche danger.
Confidence
Poor - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Strong Southwest winds overnight combined with 10-15 cm of new snow and freezing level around 800 metres. Winds becoming moderate Southwest on Sunday as another 5-10 cm of snow is forecast. Winds becoming moderate Westerly on Monday with a few more cms during the day. Drying out and cooling down overnight, followed by another pulse of moisture on Tuesday afternoon.
Avalanche Summary
No new avalanches reported. The forecast new storm is expected to increase avalanche activity over the next few days.
Snowpack Summary
A new storm slab is developing above the recent mix of surfaces which include wind slabs in alpine terrain, hard rain crusts at lower elevations and weak surface hoar crystals. Last week's heavy rain affected southern parts of the region up to alpine elevations, while the far north remained drier and generally has a weaker snowpack. Areas which previously received rain have probably now formed a hard frozen crust. Upper elevation terrain and far northern areas are likely to have wind slabs and large fragile cornices. Deeper in the snowpack, weaknesses such as the mid-November crust-facet layer still exist. Avalanches at this interface have become unlikely, although the consequences of a release remain high. This layer may be more sensitive to triggering in steep, unsupported high alpine terrain, or in the far north of the region.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.