Kootenay Boundary

Fair - Forecast snowfall amounts are uncertain

Tuesday night: 20-30cm. Wednesday: 5-15cm. Freezing level rising to 1500m. Strong south-west winds. Thursday: Moderate snow. Strong south-west winds. Friday: Generally drier conditions. Weather forecasters have low confidence at the moment (read more in the Forecaster's Blog). Be prepared for local variations in weather, and assume the avalanche danger is elevated in areas with enhanced snow, rain or wind.

A natural and skier-triggered avalanche cycle with slabs up to size 2 was observed over the last couple of days. These were failing on the mid-December surface hoar on north through east aspects from 1700m to the peaks. Wind loading from the south-west overnight Sunday led to naturally-triggered wind-slabs on lee slopes on Monday morning. Touchy conditions are likely to continue through the forecast period and avalanches are likely to increase in size as snow-loading builds.

Up to 30cm of new snow has been redistributed by westerly winds into touchy wind-slabs on lee slopes. Two buried surface hoar layers are causing concern in the upper snowpack. The most recently buried of these is only about 10-15cm deep but is reactive in snowpack tests. The second, a buried surface hoar layer from mid-December around 30-40cm down is now highly reactive, with enough snow above it to put it in the prime range for human-triggering (especially in areas which have received enhanced snowfall. It may take a little bit longer for the Rossland Range to get to this point). It is well-preserved with 10-15mm crystals and is most reactive well below ridges in protected terrain. The mid-pack is generally well settled. Facets exist at the base of the snowpack.