Regions
Kootenay Boundary.
If solar radiation is strong on Tuesday, the Avalanche Danger may rise to High. Be conservative in your terrain selection as the snowpack adjusts to the shock of recent heavy rain, snow, and now sun.
Confidence
Fair - Timing or intensity of solar radiation is uncertain on Tuesday
Weather Forecast
Mostly clear skies are forecast for Tuesday as a ridge of high pressure strengthens. On Tuesday night and Wednesday, expect light snowfall (up to 10cm) as a weak front spreads moisture to the region. On Thursday, the region should see a mix of sun and cloud with possibility of snowfall towards the end of the day. Winds should remain generally light, ramping up to moderate from the southwest as Thursday's system rolls in. Freezing levels should hover around 1800m on Tuesday, 1900m on Wednesday and 2000m on Thursday.
Avalanche Summary
At the time of publishing this bulletin no new avalanche activity had been reported. My best guess is that there was a healthy round of storm slab activity in response to all the new snow and wind on Sunday. Looking forward, I`m sure the new storm slab will remain sensitive to human triggering in high elevation, wind-exposed terrain. Also, sun on Tuesday will likely spark a round of loose wet/ wet slab avalanche activity on steeper, sun-exposed slopes.
Snowpack Summary
Heavy rain on Saturday soaked the snowpack up to ridge tops. On Sunday, heavy snowfall (up to 35cm) and southwest winds developed new storm slabs that may be easy to trigger, and may allow for long propagations where they are sitting on a crust/facet combination. The most prominent feature in the snowpack is the thick late-February crust located about 20cm below the recent storm snow. Limited reports suggest this crust is breaking down in some areas, while it remains supportive all the way to ridge crest in other spots. Deeply buried persistent weak layers still exist in the snowpack. These layers have not been reactive lately, however the extremes of warm weather followed by heavy loading due to rain then followed by snow, make it difficult to assess how the snowpack will respond.
Problems
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
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.