Kootenay Boundary

Deeply buried weak layers exist throughout the region and a cautious approach remains critical. Don't let the lure of powder pull you into bigger terrain.

Moderate - Intensity of incoming weather systems is uncertain on Thursday

Friday: 10-15cm of new snow / Moderate westerly winds / Freezing level at 1400mSaturday: Light flurries / Moderate northwest winds / Freezing level at 1500mSunday: 5-10cm of new snow / Light southwest winds / Freezing level at 1700mNote: Confidence is low for forecast wind values and precipitation amounts for Saturday and Sunday.

Reports from Tuesday reflect increased visibility over terrain that was obscured during Monday's storm. Evidence of a natural avalanche cycle involving each of our persistent weak layers was observed, with numerous avalanches reaching Size 3.5 and several crown fractures up to 3 metres deep. These are believed to be some of the deepest crowns in the region's historical record. Here's a great MIN post from Kootenay Pass that details some of the recent activity.On Wednesday, explosives avalanche control in the mountains near Nelson triggered a handful persistent slab avalanches in the size 3-4 range at treeline and in the alpine. Looking forward, expect newly formed wind slabs and the persistent slabs beneath them to remain reactive to human triggers with the potential for very large and destructive avalanches.

During the last few weeks of January, storms brought around 100 cm of snow to the region. On Monday precipitation fell as rain below about 1300 metres and a near-surface crust may exist in some areas below treeline. Where more recent precipitation fell as snow, southwest winds may have formed touchy wind slabs in high elevation lee terrain.The critical instabilities, however, are buried well below the surface. A mixture of weak surface hoar and/or a crust from mid-January is buried beneath all the storm snow at 80-110cm deep. Numerous recent avalanches to size 2.5 have been reported on this layer and large, destructive avalanches at this interface remain a concern.Below this layer lies a second crust/surface hoar interface buried early-January that is now 110-130 cm deep. Several recent avalanches have stepped down to this layer.The mid-December surface hoar layer is buried 120-150 cm below the surface. This layer has continued to produce step down releases and "sudden" test results. It is most pronounced at treeline, but is also present below treeline .