Kootenay Boundary

Fresh wind slabs will form on Friday, but the main concern is still persistent weak layers at lower elevations.

High -

THURSDAY NIGHT: Cloudy with isolated flurries, light southwest wind, alpine temperatures drop to -12 C.FRIDAY: Cloudy with flurries and 5-10 cm of snow, moderate southwest wind, alpine high temperatures around -10 C.SATURDAY: Mix of sun and cloud with isolated flurries, light northwest wind, alpine high temperatures around -10 C.SUNDAY: Sunny with cloudy periods, light wind, alpine high temperatures around -10 C.

On Wednesday, several avalanches were reported on south aspects including some natural slabs (up to size 2) and loose dry avalanches. A few skier triggered slabs were also reported (size 1-1.5), primarily on south aspects.On Tuesday, a notable size 3 persistent slab avalanche occurred on an east aspect between 1800-2100 m. This avalanche was triggered by explosives and it reportedly failed on the persistent weak layer that was buried on February 7th. This layer is discussed further in the Snowpack Summary below.Human triggered avalanches have been reported everyday for over a week. Although most avalanches have been small (size 1-1.5), some have shown impressive propagation. Check some of the recent MIN reports for examples (here and here).

Depending on location, the snow surface may consists of 20-30 cm of low density snow, wind slabs, and/or sun crusts (on south-facing slopes). A weak layer of surface hoar (feathery crystals) and a crust that was buried on February 7th is now 30-50 cm deep. This layer has been reactive, and has produced avalanches as large as size 3. Two other surface hoar layers are buried 50 to 80 cm deep the snowpack (referred to as the February 1st and mid-January layers). Although they have not been reactive recently, they are still being monitored by professionals. These layers are most prevalent below treeline on shady aspects. The lower snowpack is considered generally strong.