Kootenay Boundary

New snow and wind Thursday night could awaken the 40 to 70 cm slab that is forming above the mid-February persistent weak layer. This interface will likely be most sensitive to both natural and human triggering on south facing slopes.

Low - Timing, track, or intensity of incoming weather system is uncertain on Thursday

The region looks to be quite stormy Thursday night into Friday, and then a few flurries should linger into Saturday. Beyond that, it looks like we move into a high and dry period. THURSDAY NIGHT: 5 to 20 cm of snow, freezing level near valley bottom, strong southeast wind.FRIDAY: Overcast, freezing level rising to around 900 m, light to moderate southeast wind, 2 to 10 cm of snow possible. SATURDAY: Broken cloud cover, freezing level rising to around 1300 m, light northeast wind, a few cm of precipitation possible.SUNDAY: Broken cloud cover, freezing level rising to around 1000 m, light west/northwest wind, no precipitation expected.

Control work Wednesday produced storm slabs to size 2 on southeast, south, southwest and northwest facing features between 1800 and 2100 m. A skier triggered size 1.5 storm slab was reported from a southwest facing feature at 2000 m. Relatively deep storm slabs were sensitive to human triggering on Tuesday to size 1.5 on south and east facing terrain between 1700 and 2000 m. Crown heights were between 25 and 60 cm. Widespread sluffing was also reported.On Monday control work produced wind slab avalanches to size 1 on south and east facing features around 2150 m. A skier triggered size 1.5 avalanche was reported on a southwest facing feature at 2000 m which likely ran on the February 23rd sun crust that was buried by the recent storm. Loose dry avalanches to size 1 were also reported from northwest through northeast facing terrain between 2000 and 2100 m. On Sunday in the southern portion of the neighboring South Columbia region a skier triggered size 2 avalanche was reported from a southwest facing slope at 1550 m. The avalanche had a crown 40 to 60 cm in depth and ran on the mid-February weak layer.

The region picked up 20 to 40 cm of new snow Tuesday and Wednesday which adds to the two successive storms over the weekend that produced 10 to 40 cm of new snow. The weekend storm was accompanied by wind out of the southwest, west and northwest. In some locations this snow rests on the February 23rd weak layer which is composed of small surface hoar on polar aspects and a thin crust on solar aspects. 40 to 70 cm of snow now rests on the mid-February weak layer that is composed of facets, surface hoar and a sun crust on solar aspects.Deeper in the snowpack weak layers that formed in January and December are gradually gaining strength. Several surface hoar and facet layers are buried 1 to 2 m below the surface and there is a crust/ facet interface near the base of the snowpack. No avalanches have been reported on these layers for the past two weeks and snowpack tests are showing improved bonding. Despite these signs, avalanche professionals are still treating these layers with respect and being cautious around shallow start zones and big avalanche paths.