Regions
Northwest Coastal.
Forecast new snow and strong winds Thursday night are expected to create fresh storm slabs reactive to human triggers in wind effected terrain.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
TONIGHT: 5-10 cm new snow. Strong to extreme southeasterly ridgetop winds. Freezing level around 500 m.FRIDAY: 5-10 cm new snow. Strong southerly ridgetop winds. Freezing level around 1000 m.SATURDAY: 5-10 cm new snow. Light southeasterly ridgetop winds. Freezing level around 1000 m.SUNDAY: Mix of sun and cloud. Light northeasterly ridgetop winds. Freezing level rising to around 1300 m.
Avalanche Summary
On Wednesday, a size 2.5 persistent slab avalanche was remotely triggered by a group of skiers on a ridgetop from 10 m away. The avalanche failed on surface hoar about 70 cm deep on a north aspect at 1800 m. A size 2 wet slab was triggered by day-time warming in the same area near Bear Pass.
Snowpack Summary
5-15 cm of new snow and strong southeasterly winds have formed fresh storm slabs.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.