Kootenay Boundary

Expect stability to deteriorate as our new snow consolidates into a more cohesive slab. Be especially vigilant in wind affected areas.

Moderate - Wind speed and direction is uncertain

Monday: Mainly cloudy with isolated flurries and a trace of new snow. Winds light to moderate from the southwest. Freezing level to 600 metres with alpine temperatures of -13. Tuesday: Mainly cloudy with flurries bringing 5-10 cm of new snow overnight. Winds moderate from the northwest, increasing to strong in the evening. Freezing level to 700 metres with alpine temperatures of -8 Wednesday: Mainly cloudy with isolated flurries and a trace of new snow. Winds strong from the west. Freezing level to 800 metres with alpine temperatures of -8.

Reports from Saturday include several skier triggered Size 1 slabs in the Valhallas and just north of Nelson. These released from north-facing slopes Three of the four slides were identified as storm slabs and reached up to 30 cm in depth. A MIN report from Ripple Ridge noted wind slabs forming, as well as cracking and whumphing on east aspects. Reports from Friday included two ski cut Size 1 slabs reported in the Bonnington Range and in the Kootenay Pass area. The Bonnington slide took place on a steeper northwest facing slope at 2150 metres. The MIN report of the Kootenay Pass slide suggests it took a group effort to produce the release.For Monday, keep aware of slab avalanche potential increasing as the new snow continues to settle and see wind effect. While wind slabs have become the dominating concern, the above mentioned storm slab releases also suggest the possibility for ongoing storm slab triggering potential. Although we are no longer listing a persistent slab problem, deeper instabilities in the snowpack remain an lingering concern in areas with an unusually shallow snowpack and where faceted (sugary) snow remains preserved near the base of the snowpack.

15-20 cm of new snow accumulated in the region over Saturday night, burying recently formed sun crust on steep solar aspects as well as surface hoar that has been observed at up to 15 mm on shaded aspects. Below the new snow interface, 30-50 cm of recent storm snow overlies a (February 18) sun crust on solar aspects, with around 70 cm overlying a more widespread (February 10) melt-freeze crust on shaded aspects. Variable winds have promoted wind slab formation in this storm snow on a range of aspects in wind-exposed terrain and in some areas scoured it down to the above mentioned crusts. Below the wind effect, reports suggest the storm snow is generally well bonded to the underlying crust layers.The early-February surface hoar layer is now down approximately 90-120 cm. This layer was reactive during the warm storm last week but now appears to have gone dormant. Areas with a shallow snowpack (less than around 170 cm) generally have a weak snowpack structure with a layer of sugary facets near the ground.