Dangerous avalanche conditions persist at all elevations. The snowpack will remain primed for rider triggering as natural avalanches taper off.
A weak layer of faceted grains above a crust buried 60 to 120 cm deep is a recipe for large, high-consequence avalanches. Smaller slabs can easily step down and trigger larger, more destructive avalanches.
Storm slabs remain reactive to human traffic. Slabs are particularly touchy where they sit on weak layers of facets or surface hoar. Expect deeper and touchier slabs in lee terrain features near ridges.
Numerous natural and rider-triggered storm slab and persistent slab avalanches size 1 to 3.5 with wide propagations have been reported the past few days at all elevations. Persistent slabs have been reported on all aspects and 60 to 100 cm deep. Some of the rider-triggered avalanches resulted in partial or full burials and many were remotely triggered (from a distance).
Expect storm and persistent slab avalanche activity to continue.
70 to 110 cm of recent snow sits on a variety of layers, including surface hoar in wind-sheltered terrain, weak facets, or a hard melt-freeze crust on sun-exposed south and west-facing slopes. A plethora of recent avalanche observations indicate the fresh snow is not bonding well to these layers. Gusty southerly winds have stripped fresh snow in exposed areas and loaded lee features with over 130 cm of wind-blown snow.
A thick and hard widespread crust that formed in early February is buried 60 to 120 cm deep and is found up to around 2400 m. This crust may have a layer of facets above it and is a troublesome avalanche layer.
The remainder of the snowpack is settled.
Thursday Night
Cloudy with 5 to 15 cm of snow for most areas, and hotspots of up to 30 cm focused on areas south of Hwy 1. 15 to 30 km/h southwest ridgetop wind. Treeline temperature -10 °C. Freezing level dropping to valley bottom.
Friday
Mostly cloudy with flurries and isolated sunny breaks, up to 10 cm of snow. 15 to 40 km/h southwest ridgetop wind. Treeline temperature -5 °C. Freezing level 900 m.
Saturday
Mostly cloudy with sunny breaks and isolated flurries. 15 to 30 km/h southwest ridgetop wind. Treeline temperature -6 °C. Freezing level 600 m.
Sunday
Mostly cloudy with scattered flurries, up to 10 cm of snow. 15 to 30 km/h southwest ridgetop wind. Treeline temperature -8 °C. Freezing level valley bottom.
More details can be found in the Mountain Weather Forecast.
