Spring Conditions. Forecast cloud cover, cooler air temperatures, and dropping freezing levels will all contribute to decrease the likelihood and size of avalanches. Avoid slopes that do not develop a solid crust overnight.
Weather Forecast
High cloud developing overnight with freezing levels dipping down to 2000 metres by morning. Mix of sun and cloud on Tuesday morning, becoming cloudy with moderate southwest winds in the afternoon. Freezing levels dropping to 1500 metres by Wednesday morning with moderate southwest winds and 3-5 cm of new snow above 1500 metres. Cloudy with light winds during the day on Wednesday. Mix of sun and cloud on Thursday with overnight freezing down to 1300 metres.
Avalanche Summary
Natural avalanches up to size 3.0 were reported from Sunday in the central Purcells on alpine features with solar exposed aspects. Some glide cracks were also reported releasing up to size 2.5 during the heat of the day.
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. A moist/wet, isothermal, and rapidly melting snowpack exists on all aspects below around 1500 m and probably even higher on solar aspects. The strength (thickness) of the surface crust and how quickly it breaks down during the day are important factors to focus on.
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.
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.
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.