Kootenay Boundary

Choose your terrain conservatively on Friday while waiting for the new snow to stabilize. Its effect on our deeper weak layers has yet to be seen.

Moderate -

Friday: Mainly cloudy. Winds light to moderate from the southwest. Freezing level to 1400 metres with alpine temperatures around -3. Saturday: Cloudy with scattered flurries and 5-10 cm of new snow. Winds moderate from the southeast. Freezing level to 1500 metres with alpine temperatures of -1. Sunday: Cloudy with scattered flurries and a trace to 5 cm of new snow. Winds light to moderate from the south. Freezing level to 1300 metres with alpine temperatures of -3.

A Size 1.5 slab avalanche was triggered by a skier north of Nelson on Wednesday. It occurred on a north-facing 30 degree slope at 2000 metres and features a 50 cm crown fracture. The Ferbruary 8th interface is suspected to be the failure plane. In the Rossland Range deep persistent slabs to Size 2 were reported on southeast and west aspects around 2000m on Tuesday. A thin snowpack or solar triggered sluffs stepping down to weaker faceted layers were the culprits. Of particular note was a Size 3 natural avalanche on Wolf ridge near Kootenay pass on Monday - the sun's effect is significant! See the great photo in the MIN report (here).

Upwards of 45 cm of new snow lies at the surface as of Thursday afternoon. Below the new snow, recent warming and sunny conditions gave us a widespread sun crust on all but high northerly (and some westerly) aspects, where there is still some cold snow to be found. These crusts will act as excellent sliding surfaces for our new snow.At the end of last week up to 30cm additional snow fell (mostly near Nelson), creating touchy storm slabs at all upper elevations and aspects. Slabs were reported as very reactive to human triggers and are sitting on a variety of surfaces; including scoured surfaces in wind exposed terrain, surface hoar (size 2-3 mm) in sheltered locations, and sun crust on steep solar aspects.Snowpack tests near the Valhallas have given moderate, propagation-likely results down 50-70cms on the Feb 3rd interface. Areas with a shallower snowpack (less than 150 cm) have a generally weak snowpack structure with sugary facets near the ground. This includes shallow alpine slopes and most of the Rossland range. It is possible for storm slab avalanches to step-down to these deeper weak layers, resulting in large, destructive avalanches.