Kootenay Boundary

Fair - Forecast snowfall amounts are uncertain on Saturday

A ridge of high pressure is expected to move into the region overnight. Northwest winds are expected to continue to be gusty and strong in the alpine and at treeline on Thursday. Some moisture that will remain in the area is expected to cause periods of moderate precipitation alternating with periods of thin cloud. Continued high pressure is forecast for Friday morning, before a low pressure system moves into the region from the Pacific in the afternoon. Southwest wind and moderate precipitation is forecast to begin in the late afternoon or early evening. Snow and wind should continue overnight and into Saturday. The freezing level is expected to drop down to near valley bottoms on Wednesday night, and then rise to about 1000 metres on Thursday.

We are getting reports of more frequent and larger avalanches that are running on the Feb. 8th crust and/or buried surface hoar. Avalanches up to size 3.0 were reported from the control work at Kootenay pass along the highway corridor. Remotely triggered avalanches continued to be reported. Strong winds are transporting snow into a slab above the weak layers

Another 10-15 cm combined with very strong northwest winds has added to the 30-60 cm of snow that is sitting on top of a highly reactive persistent weak layer (PWL), comprising large surface hoar in sheltered areas and a sun crust on solar aspects. This PWL is now right at the critical depth where triggering is very likely and resulting avalanches could easily be large enough to bury, injure or kill a person. Professionals throughout the region are treating this layer with extreme caution, since it is showing signs of remote triggering and the ability to propagate in low angled terrain. Alpine winds have been strong enough to blow snow around, adding a touchy wind slab problem into the mix behind exposed terrain features in the alpine. In shallow snowpack areas concerns remain for the mid-December persistent weakness down around 80-100cm and for basal facets. Treeline snowpack depths are approximately 230 cm.