South Columbia

Storm slabs continue to be a concern for human triggering. This problem is more likely where a persistent weak layer of facets and/or a crust is sitting beneath the storm snow.

Moderate - Forecast snowfall amounts are uncertain

Overnight: Unsettled with convective flurries resulting in 5-10 cm in some areas combined with moderate westerly winds and alpine temperatures around -15. Tuesday: A mix of sun and cloud with convective flurries and light southwest winds. Wednesday: Overcast with light snow and periods of heavy flurries combined with light southwest winds. Thursday: A mix of sun and cloud with flurries during the day, and a stronger system moving in late in the day.

On Sunday we had reports of storm slab avalanches releasing naturally, with explosives control, and by pushing snow with a snowcat up to size 2.0. There was also a deeper release 250 cm down, suspected to have released on buried facets that resulted in a size 3.0 avalanche in the Selkirk mountains near Trout Lake. On Saturday we had reports of widespread storm slab activity.

Just under a week of stormy weather has delivered a wide-ranging 65-120 cm of new snow to the region. Moderate to strong southerly winds accompanied the new snow, promoting touchy storm slab formation at all elevations. The new snow has buried widespread faceted surface snow, thin sun crust on steep solar aspects, as well as more isolated surface hoar to 4mm. About 90-135cm below the surface you'll find the mid-February interface which is composed of a thick rain crust up to about 1800 m, sun crusts on steep solar aspects, and spotty surface hoar on shaded aspects. This layer has seen a recent increase in more sudden snowpack test results and has been identified as a failure plane in a number of recent avalanches. Its reactivity has been especially prominent over the crust at lower elevations. Any continuing activity at this interface will likely see it emerge as a persistent weak layer.