Kootenay Boundary

The storm continues to build very touchy slabs above recently buried weak layers. Large avalanches are very likely to release naturally or be triggered by light additional loads.

Fair - Due to the number of field observations

Overnight and Tuesday: Precipitation 10-15 mm overnight becoming light in the morning as the Arctic ridge moves Southward and collides with the moist Pacific low. Temperatures trending colder as the Arctic air invades and Northeast winds build. Becoming sunny in the afternoon.Wednesday: Cold and clear.Thursday: Cold and clear.

We suspect that storm slab avalanches are releasing naturally up to about size 2.5. If a deeper instability is triggered, expect avalanches to be in the size 3.0 range. This storm needs some time to settle and bond, forecast cold temperatures may preserve recently buried weak layers and require more time to settle and bond than when the post storm temperatures are warm. This is a complex avalanche forecasting scenario; complicated by early season timing when we have few observations coming from the field.

The new storm slab is about 40-60 cm deep depending on where you are in the region. This storm slab has been reported to be releasing naturally during the storm, and is very touchy to light triggers like skiers/riders. Storm slabs are sitting above recently buried weak layers of surface hoar on North aspects and melt/freeze crusts on solar aspects. There are some reports of a deeply buried early season crust that formed in October. We do not know the extent of this layer with respect to aspect and areas within the region. In other regions of the interior mountains, this layer is more likely to be found in the high alpine on northerly aspects.