We have some uncertainty about the likelihood of persistent slabs. In times of uncertainty, conservative terrain choices are the best defense. Seek out low consequence terrain.
Rider triggerable wind slabs could still linger in the alpine. If triggered, wind slabs may step down to deeper layers, causing larger avalanches.
A layer of facets over a crust is buried 80 to 150cm, and has recently produced very large avalanches. It appears to be most reactive in areas closer to the coast.
On Saturday, a skier-triggered size 2 persistent slab avalanche was reported on the US side of the border. This avalanche occurred on a northwest aspect at approximately 1500 m and ran on the mid February layer. This layer is a concern in our region as well.
We suspect that avalanche activity has been tapering off over the past few days but observations have been limited. If you are heading into the mountains please consider filling out a Mountain Information Network report.
At ridgeline and in exposed terrain, strong winds have left slabs and hard wind-pressed surfaces. Soft snow may still be found in wind-sheltered areas or faceting northerly aspects. A sun crust may exist on or near the surface on sun-exposed slopes.
A persistent weak layer of facets and a crust is buried 80 to 150cm and extends up to around 1400 m. The greatest concerns for triggering are large triggers such as cornice fall, or human-triggering in areas where the snowpack transitions from thin to thick. It also appears to be most reactive in areas closest to the coast, with diminished reactivity further inland.
Wednesday Night
Clear skies. 10 km/h south ridgetop wind. Treeline temperature -7 °C.
Thursday
Mostly sunny. 10 km/h south ridgetop wind. Treeline temperature -9 °C.
Friday
Mostly cloudy. 20 km/h southeast ridgetop wind. Treeline temperature -7 °C.
Saturday
Mostly cloudy. 4 to 10 cm of snow. 30 km/h south ridgetop wind. Treeline temperature -5 °C.
More details can be found in the Mountain Weather Forecast.
