Kootenay Boundary

Choose terrain that is sheltered from the wind to find the softest snow, and the lowest avalanche danger.

On Sunday in the backcountry near Big White, a skier accidently trigger a large (size 2) slab avalanche. This avalanche sympathetically set off a 100 m wide additional slab propagation and subsequently a settlement crack was observed and estimated to be 1 km in length.

In general, small, human-triggered wind slab avalanches continue to be reported In alpine and open treeline terrain. Most of these avalanches are 20 cm deep or less. See pictures below.

Alpine and open treeline terrain are generally wind-affected, with reactive wind slabs in some places. At the surface in most areas, surface hoar is forming in wind protected terrain. Around Nelson and in the Valhallas, small (5 mm) surface hoar (weak, feathery crystals) have been reported to be buried 15-20 cm below the snow surface.

Facets (weak, sugary crystals) are starting to form above a thick rain crust that was buried in early February. This crust is now 30 to 50 cm below the snow surface.

The mid and lower snowpack presents as settled, with snowpacks depths decreasing rapidly on terrain below 1000 m in elevation.

Monday Night

Mostly cloudy. 1-5 cm of snow expected. Light variable ridgetop wind. Treeline around -4 °C. Freezing level 1000 m.

Tuesday

Mostly cloudy. 1-5 cm of snow expected above 1000 m. Light southwest ridgetop wind. Treeline temperature around -4 °C. Freezing level expected to maintain @ 1000 m throughout the day.

Wednesday

Mostly cloudy. trace amounts of snow expected. Light southwest ridgetop wind. Treeline temperature around 0°C. Freezing level at valley bottom overnight, rising to 1600 m through the day.

Thursday

Mostly cloudy. trace amounts of snow expected. Light southwest ridgetop wind. Treeline temperature around 0°C. Freezing level at valley bottom overnight, rising to 1600 m through the day.

More details can be found in the Mountain Weather Forecast.

• Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
• Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
• Start with conservative lines and watch for clues of instability.
• Even a small avalanche can be harmful if it pushes you into an obstacle or a terrain trap.