Regions
Northwest Coastal.
Forecast heavy precipitation, very strong winds, and rising freezing levels will result in High avalanche danger at all elevations.
Confidence
Poor - Due to the number of field observations
Weather Forecast
Tonight and Saturday: Continued warming with freezing levels remaining at about 1500 metres. Expect 15-30 mm of precipitation overnight and another 20-30 mm during the day. Very strong Southwest winds during the storm.Sunday: A moist onshore flow will bring continued snow at higher elevations. The snow line should start lowering during the day, with very strong Southwest winds continuing during the day. Freezing levels dropping back down to about 800 metres by the evening.Monday: Some flurries combined with strong Southwest winds. Freezing levels at about 600 metres.
Avalanche Summary
The warm new storm snow is not expected to bond well to the shallow weak snowpack. Expect natural avalanche activity and easy triggering from skiers and sledders. Steep terrain at lower elevations may experience a cycle of moist or wet natural avalanches releasing at or near the ground, due to forecast rain falling on snow.
Snowpack Summary
Warm and wet Pacific moisture continues to build a storm slab at higher elevations. Rising freezing levels and continued precipitation are expected to create a moist slab above recent buried weak layers that may continue to release naturally. Rain on snow at lower elevations is expected to saturate the shallow snowpack. Very strong to extreme winds are creating deep pockets of wind transported snow at higher elevations.
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.