Regions
Kootenay Boundary.
Forecast snow and wind are expected to increase the avalanche danger. Be prepared for winter conditions at higher elevations.
Confidence
Poor - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
The first wave of precipitation and strong southwest winds is expected to end Saturday evening, and there should be a short break before the next wave starts on Sunday morning. The freezing level should gradually drop on Sunday, with most of the forecast 10-15 mm of precipitation coming as snow above 1200 metres combined with moderate southwest winds. Snow/rain should end late Monday morning or early afternoon, but remain cloudy. Mostly cloudy with a chance of sunny periods on Tuesday as the freezing level rises to about 2000 metres.
Avalanche Summary
No new avalanches reported. I suspect wet conditions with poor visibility have limited observations. Heavy precipitation in the south of the region may have resulted in loose wet and wet slab avalanches in areas that have not had a re-freeze for several days.
Snowpack Summary
Rain up to at least 2000 metres on Saturday may increase the likelihood of triggering a wet slab avalanche on one of the buried persistent weak layers. Strong southwest winds combined with new snow at higher alpine elevations may have developed new wind slabs that are easy to trigger, and may allow for long propagations where they are sitting on a crust/facet combination. In many areas, the snowpack is becoming moist and slowly turning into a more uniform, springtime snowpack. The surface has only seen limited refreezing these last few days. The most prominent feature in the snowpack is the thick late-February crust, down 5-20 cm. Limited reports suggest this crust is breaking down in some areas, while it remains supportive all the way to ridge crest in other spots. There are still weak layers below this crust. It is unclear whether these deeper layers are still reactive, but I would go with caution in case they are.
Problems
Wet Slabs
Wet Slab avalanches are the release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slabs can be very unpredictable and destructive.
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.