Spring Conditions. Forecast new snow and wind will bring back that winter feeling in the mountains. Watch for new wind slabs that may not bond to the old hard surface.
Weather Forecast
Strong southwest winds and light snow overnight with freezing levels dropping down to 1500 metres. Light winds on Wednesday with a mix of sun and cloud, and a chance of some convective flurries. Freezing levels rising up to 1800 metres during the day. Freezing down to about 1400 metres by Thursday morning under mostly clear skies. Sunny with light northerly winds on Thursday and freezing levels rising up to 2000 metres. Mostly cloudy on Friday with scattered flurries.
Avalanche Summary
On Monday we had a report of a natural cornice fall size 2.5 from a north aspect at 2350 metres in the Selkirks. One natural size 3.0 avalanche was reported from a southeast aspect in the alpine that released at 2700 metres and ran about 1000 metres; this occurred in the southern Selkirks on Sunday. Most commercial operations have closed for the season, and data is becoming sparse.
Snowpack Summary
The snow surface is currently going through a typical spring melt-freeze cycle on all aspects and at all elevations, except possibly high true-north slopes which could be holding onto cold snow. The strength (thickness) of the surface crust and how quickly it breaks down during the day are important factors to focus on. Forecast wind and snow may bring back a winter feel above treeline for a day or two. Watch for new wind slabs that may not bond to hard old surface crusts.
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.
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.
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.