Kootenay Boundary

We are entering a 'low probability/high consequence' phase with a tricky persistent weak layer. Check out this blog post on difficult decision making and current conditions.Avoid large, unsupported slopes, especially on north aspects.

Fair - Timing, track, or intensity of incoming weather system is uncertain

A low pressure system moves onto the coast Saturday night and should reach the southern interior by Sunday afternoon. Light flurries and rising temperatures are expected for Monday and Tuesday.Sunday: Light snowfall in the morning, increasing in the afternoon, 6-12cm, treeline temperature around -12C, ridgetop winds 30-50 km/h SWSun. Night/Monday: Snowfall 5-10cm, freezing level around 800m, ridgetop winds 30-50 km/h SWTuesday: Flurries 2-5cm, freezing level around 1300m, ridgetop winds 20-40 km/h SW

On Friday, a size 1.5 skier accidental avalanche was reported.  It released at a depth of 30-45cm.On Thursday, two skier accidental avalanches were reported in the KB. These were size 1.5 and 2. The deeper released down 70cm. Also reported were three remotely triggered avalanches up to size 2. The furthest away trigger was 40m. Two natural avalanches were reported up to size 2.5 and were likely triggered by the sun.

The primary concern is a persistent slab (typical thickness 50-90cm) from the last series of storms that is sitting on a stubborn persistent weak layer consisting of facets, surface hoar, melt-freeze crusts, or any combination of these. This weak layer is widespread at all elevations and aspects. Recent test results are suggesting that the layer is still easy to trigger in some areas but may becoming harder to trigger in other areas. We are still receiving isolated reports of large settlements or whumpfing which suggests the layer still has the potential for large propagations. In many areas the layer has the potential to produce large, destructive avalanches. The phase we are now entering is referred to a 'low probability/high consequence' problem. Continue to use conservative terrain choices until you are sure the layer is no longer unstable in your local area. Strong forecast winds from the SW are expected to create touchy new wind slabs on leeward slopes and cross-loaded features. On south aspects, a sun crust has formed on the surface. New surface hoar formation up to 10mm and near-surface faceting have been observed.  The new storm snow will overlie these layers.