Kootenay Boundary

It appears that we've hit the tipping point, very large avalanches ran nearly full path Wednesday, and this activity will likely persist into Thursday. Don't over-think it, just avoid avalanche terrain, our snowpack needs time to adjust.

Moderate - Freezing levels are uncertain on Saturday

Snowfall is expected to spread into the BC interior Thursday morning. With cold arctic air preconditioning, a widespread 5 to 15 cm of snow is expected with locally higher amounts throughout the region. A ridge of high pressure and rather warm air should begin to spill into the region Saturday and Sunday.THURSDAY: Overcast, freezing level at valley bottom, light to moderate south/southwest wind, 5 to 15 cm of snow expected with potential for up to 25 cm in favored locations. THURSDAY NIGHT: Overcast, freezing level at valley bottom, light west wind, 1 to 5 cm of snow possible.FRIDAY: Overcast, freezing level at valley bottom, light west wind, trace of snow possible.SATURDAY: Scattered cloud, freezing level beginning near valley bottom, rising to 800 m during the day, returning to valley bottom Saturday night. Light west wind, no precipitation expected.

On Wednesday control work produced very large avalanches to size 3.5 on southwest, south and southeast aspects. Natural avalanches ran to size 2.5 on southeast, east and northeast aspects. These avalanches may have started as storm slabs, but quickly stepped down to the mid-December and/or late November weak layers. These very large avalanches are not to be taken lightly and this activity may persist into Thursday.On Tuesday a widespread natural avalanche cycle to size 2.5 was reported from all aspects and elevations as the upper snowpack adjusted to a new load and increasingly warm temperatures.Last Thursday a skier triggered a size 3.0 avalanche just after entering the east face of Evening Ridge near Nelson. The skier survived, but sustained significant injuries. On New Years Eve a skier triggered a size 3.0 avalanche on an east facing treeline feature at Kootenay Pass which resulted in a single fatality. Both of these avalanches are thought to have failed on the late November crust.

40 to 60 cm of recent snow is coalescing into a slab on top of the January 5th interface which consists of a crust/surface hoar combination on steep southerly aspects and pure surface hoar on remaining aspects. The late December surface hoar remains active and is now down 50 to 70 cm below the surface. The mid-December surface hoar, facet and crust combination is now down 70 to 130 cm below the surface and remains active. This interface is most pronounced at treeline, but is present below treeline also. The overlying slab is now deep and cohesive. Two laminated crusts created by twin rain events in late November lay just below the mid-December interface, 80 to 150 cm below the surface. Facets may be found sandwiched between the two crusts and have been observed above the uppermost crust too. In shallow rocky terrain the mid-December surface hoar and the late November crust seem to be reacting together which is a volatile combination.