Regions
Kootenay Boundary.
Give the new snow time to stabilize before committing to big terrain. The Avalanche Danger may change quickly in the spring. Even brief periods of sun can trigger pushy loose wet avalanches or promote destructive cornice falls.
Confidence
Moderate - Intensity of incoming weather systems is uncertain on Sunday
Weather Forecast
10-15cm of new snow is forecast for Sunday night while lingering flurries are expected on Monday. On Tuesday and Wednesday the region will see mainly sunny skies as a ridge of high pressure develops over the province. Ridgetop winds should be moderate from the west on Sunday night, becoming moderate and northerly by Monday afternoon. On Tuesday and Wednesday, winds will be light. Freezing levels will sit at about 1700m on Monday, and then rise to about 2000m on Tuesday and Wednesday.
Avalanche Summary
No new avalanches were reported on Saturday. A new round of storm slab activity is expected in response to new snow and moderate winds on Sunday. Storm slab activity may persist for longer than usual due to underlying surface hoar. If the sun comes out on Sunday, loose wet avalanche activity can also be expected in steep, sun-exposed terrain.
Snowpack Summary
As of Sunday morning, 1-8cm of new snow sat above small surface hoar on shaded slopes and a melt-freeze crust on sun-exposed slopes. About 35cm below the surface, you'll likely find another hard crust which exists everywhere except high, north-facing terrain. The late February persistent weak layer down 70 to 120 cm remains a low probability / high consequence concern. Test results are variable, with occasional sudden planar (pop) results. While generally becoming unlikely to trigger, this layer could wake up with a cornice fall, warm temperatures or from a thin snowpack area. Cornices are large and looming in some areas.
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.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.