Regions
Kootenay Boundary.
The weekend's storm instabilities are expected to linger for a few days. Use extra caution on steep south-facing slopes during the afternoon if the sun is out in full force.
Confidence
Moderate - Timing or intensity of solar radiation is uncertain
Weather Forecast
A ridge of high pressure will bring dry and partly sunny conditions on Monday. Freezing levels are expected to be around 1000m and ridgetop winds should be light from the north. Increased cloudiness is expected for Tuesday with freezing levels falling to near valley bottom and light to moderate alpine winds from the NW. Dry and sunny conditions are expected for Wednesday.
Avalanche Summary
No new natural avalanches have been reported since Wednesday. On Saturday, explosives triggered storm slabs up to size 2. These slabs were 5-15cm thick and were running on the thick melt-freeze crust.
Snowpack Summary
10-30cm of recent snowfall sits over a thick rain crust. This crust is being reported as high as 2400m. At treeline elevation this crust is thick and supportive, and should be capping any deeper weaknesses. The weak layer from early December has recently become inactive, likely due to all the moisture in the snowpack. The mid and lower snowpack is reported to be moist or wet to the ground at treeline elevations.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.