Kootenay Boundary

Spring conditions. While the freezing level remains high, wet slabs will be the primary concern.

On Saturday, light rain is forecast, with light to moderate SW winds and the freezing level around 2500 m. A cold front arriving on Sunday brings 10-20 cm snow, with the freezing level falling to around 1700 m by afternoon. Skies start to clear on Monday.

Most commercial operations have closed for the season, and observations are becoming sparse.

Monitoring the overnight freeze of the snow surface is very important during the spring. If the snow surface does not freeze overnight or if the crust is only a few cm thick, the effect of daytime heating and solar radiation will weaken the snowpack much more quickly than it would if there is a well frozen thick crust. This is because the crust must first melt before the sun can weaken the snowpack. Deeply buried weak layers in the mid snowpack and near the ground still have the potential to wake up and become active with a rapid warm up. While unlikely, releases on these deeply buried weak layers would result in very large avalanches. Glide cracks are widespread, active, and best avoided. Cornices are large, fragile, and could trigger deep slab avalanches that run to valley bottoms. The snowpack in many areas has become isothermal, meaning the snowpack is 0 degrees Celsius throughout. An isothermal snowpack is more prone to full depth wet slab avalanches during the heat of the day.