Regions
Northwest Coastal.
Forecast new snow and wind Wednesday night are expected to create fresh storm slabs reactive to human triggers.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
TONIGHT: 5-15 cm new snow. Strong southeasterly ridgetop winds. Freezing level around 500 m.THURSDAY: Cloudy with flurries. Light southwesterly ridgetop winds. Freezing level around 1000 m.FRIDAY: 5-15 cm new snow. Strong southwesterly ridgetop winds. Freezing level around 1000 m.SATURDAY: 5-10 cm new snow. Moderate southwesterly ridgetop winds. Freezing level around 1000 m.
Avalanche Summary
Numerous natural loose wet avalanches on all aspects up to size 2 and several natural wind slabs on north aspects up to size 2.5 were reported near Bear Pass on Tuesday. Forecast snow and wind on Wednesday night are expected to create fresh storm slabs reactive to human triggers.
Snowpack Summary
Rain and warming to ridge top elevations have created wet or moist snow in the top 20-30 cm of the snowpack that is likely to be covered by 5-15 cm of new snow by Thursday morning. The new snow and strong southeasterly winds are expected to form fresh storm slabs reactive to human triggers. In the south of the region, two layers of surface hoar are buried approximately 70-100 cm deep. The layers are most prominent on north to east aspects and were buried early-March and mid-March. In the north of the region, these layers are around 40 cm deep.Bellow these March layers the mid-pack is generally well-settled and strong. However, shallower parts of the region, such as the far north, have weak sugary facets near the bottom of the snowpack.
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.