Regions
Kootenay Boundary.
Avalanche Danger is trending down due to below freezing temperatures after the recent rain.
Confidence
Fair - Due to the number and quality of field observations
Weather Forecast
Clearing skies and cooling temperatures are forecast for Saturday night. Freezing levels are expected to drop down to valley bottoms by Sunday morning. It should be mostly clear with light winds on Sunday, but some areas may have valley cloud in the morning that might persist during the day. Freezing levels are forecast to rise up to 1500 metres during the day and then drop down to valley bottoms by Monday morning. Clear with light winds during the day on Monday. Cloud is forecast to move in from the Southwest on Tuesday, but so far it does not look like there is much precipitation associated with this cloud.
Avalanche Summary
No new reports of avalanches from this region
Snowpack Summary
Rain from the past week has saturated the snowpack in most areas, and a hard crust likely exists to about 2100m. The thickness of the crust will depend on elevation and how much rain fell. At higher elevations, snow and strong winds have added depth and cohesion to a storm slab which may be sitting on a weak layer of hard rain crust, facets, and/or surface hoar. Near the base of the snowpack is a crust/facet combination which formed in November. This interface remains a concern at higher elevations in many parts of the region as it continues to produce whumpfing, and has the potential for wide propagations.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.