Kootenay Boundary

Slightly warmer temperatures and new snow may increase the reactivity of persistent slabs

Avalanches are possible where the upper snowpack whumpfs, cracks or feels slabby under your feet

On Wednesday a rider remotely triggered a persistent slab avalanche (size 2) on a southeast aspect just above 2000 m. The party indicated that they felt whumpfing on the approach as they left treeline. Dry loose sluffing continues to be observed from steep terrain features.

Rider triggering remains possible at all elevations where a stiffer slab exists above the late January buried weak layers.

Exposed terrain in the alpine and treeline is variably wind-affected. New surface hoar is forming and steep south facing slopes may host a thin suncrust.

20 to 60 cm of faceted snow overlies a weak layer from late January. This layer consists of a crust on sun exposed slopes and a layer of surface hoar on all other aspects. Snowpack tests clearly show this layer exists, but it may require a stiffer and more cohesive slab above to be reactive.

The mid and lower snowpack is generally well settled.

Thursday Night

Cloudy with isolated flurries. 10 km/h east ridgetop wind. Treeline temperature -8 °C.

Friday

Cloudy with new snow 5 to 10 cm. 10 to 20 km/h southwest ridgetop wind. Treeline temperature -7 °C.

Saturday

Cloudy with sunny periods. 10 to 20 km/h northwest ridgetop wind. Treeline temperature -9 °C.

Sunday

Cloudy with flurries up to 5 cm. 10 to 25 km/h southwest ridgetop wind. Treeline temperature -7 °C.

More details can be found in the Mountain Weather Forecast.

• Be careful as you transition into wind-affected terrain.
• Approach steep and open slopes at and below treeline cautiously, as buried surface hoar may exist.
• Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.