North Columbia

Fresh storm slabs may be reactive to human triggering. Watch for signs of instability such as whumphing, cracking and recent avalanches.

Moderate -

THURSDAY NIGHT - Mainly cloudy with isolated flurries, up to 5 cm / west winds 20-40 km/h / alpine low temperature near -11FRIDAY - Mainly cloudy with isolated flurries, 5 cm / west winds 10-20 km/h / alpine high temperature near -9SATURDAY - A mix of sun and cloud / northwest winds 10-15 km/h / alpine high temperature near -10SUNDAY - Sunny with cloudy periods / west winds 10-20 km/h / alpine high temperature near -8

On Thursday, there were preliminary reports of size 1-1.5 loose avalanches, and size 1 human triggered storm slab avalanches.On Tuesday there was one size 1 human triggered persistent slab avalanche reported on a north aspect at 1100 m. It failed on the late January persistent weak layer, 40 cm deep and was triggered remotely (from a distance).Generally speaking, reports from the past week are mainly of wind slabs reacting to ski cuts, with a trend toward smaller (size 1) releases. Small (size 1-1.5) loose dry avalanches have also been observed releasing naturally from steeper, sun exposed slopes in recent days.Reports of human triggered persistent slab avalanches on the January weak layers have been on the decline, suggesting these layers have evolved into a lower likelihood/high consequence avalanche problem.

10-25 cm of new snow sits on wind slabs, surface hoar (feathery crystals), and facets (sugary snow) and a crust on sun exposed slopes. The buried wind slabs are also sitting on facets and they may continue to be reactive. There are a two prominent weak layers in the upper snowpack that were buried in mid and late January. These can be found approximately 40-80 cm deep. Both layers consist of surface hoar and may be associated with a crust on steep, south facing slopes. These weak layers have been most reactive at lower elevations, and especially below treeline.The lower snowpack is generally considered to be strong, except for shallow, rocky areas where the cold temperatures continue to facet (weaken) the snowpack.