Wind slabs that overlie faceted snow could remain surprisingly reactive to human triggers. Err on the side of caution when evaluating older slabs, especially near shallow, rocky areas.
Continuing light snowfall and southerly winds are promoting wind slab formation on an ongoing basis.
Investigate for wind slab around ridges or lee features and use wide safety margins - remote triggering has been observed.
Periods of sun could destabilize snow on steep, south facing slopes. Recent snow may shed naturally or with a human trigger.
Skiers remote-triggered a large wind slab from 100 m away in the Little Simpson area on Hudson Bay Mountain on Monday. It failed on faceted snow, a reminder that persistent grains may extend the reactivity of wind slabs.
Up north, a 40 cm-deep layer of surface hoar on the early-December crust was recently reactive to skiers in the Ningunsaw area. The Ningunsaw slide path produced size 2.5 and size 3 avalanches on Monday and Tuesday night.
Share your observations on the MIN!
Light new snow amounts have been combining with an aging wind slab problem and with otherwise heavily wind affected surfaces in the alpine and at treeline.
The crust from early December is now buried approximately 30 to 50 cm deep. In some areas, large surface hoar crystals are found at this interface. We are trying to track the distribution of this surface hoar across the region. Faceted snow is perhaps more likely to find at this interface and poses a similar problem.
The are no layers of concerns below the early December crust.
Thursday night
Cloudy with scattered flurries and less than 5 cm of new snow. 15 to 30 km/h southwest ridgetop wind. Treeline temperature -4 °C.
Friday
Partly cloudy. 15 to 30 km/h southwest ridgetop wind. Treeline temperature -5 °C.
Saturday
Mainly cloudy with isolated flurries. 10 to 20 km/h southeast ridgetop wind. Treeline temperature -7 °C.
Sunday
Mainly cloudy with isolated flurries. 5 to 10 km/h southeast ridgetop wind shifting southwest. Treeline temperature -6 °C.
More details can be found in the Mountain Weather Forecast.
