Avalanche Forecast
Regions: South Columbia.
Confidence
Moderate - Timing or intensity of solar radiation is uncertain on Saturday
Weather Forecast
Mostly clear overnight with light westerly winds and freezing down to valley bottoms. On Saturday, a mix of sun and high cloud with light southwest winds and freezing levels rising to 1700 metres. Cloud and light precipitation developing by Sunday morning with freezing down to at least 1000 metres. On Sunday, cloudy with 5-8 cm of snow and freezing levels rising up to 1300 metres. Light snow and light winds continuing on Monday, before the next ridge of high pressure brings back the clear skies.
Avalanche Summary
No new reports of persistent slab avalanches. On Thursday there were numerous reports of new storm slab avalanches up to size 1.5 from various aspects at and above treeline. There was also some loose wet avalanche activity in the afternoon on Thursday when daytime warming weakened the new storm snow on solar aspects. On Wednesday we had reports of loose wet solar induced activity in most areas up to size to size 2.0, as well as some thin wind slabs in the high alpine on shaded aspects.
Snowpack Summary
New storm slabs have developed above a mix of surfaces, including crusts on solar aspects, moist snow up to treeline, and dry snow or recent wind slabs in the alpine on shaded aspects. Cornices continue to be described as large and fragile. The late February persistent weak layer is an aspect dependant mix of surface hoar, facets and/or a thick crust down around 60 to 110 cm below the snow surface. Commercial operators continue to see hard sudden planar results in snowpack tests, which suggests that wide fracture propagations are possible. New storm loading above the buried persistent weak layer may increase the likelihood of triggering large avalanches. Expect loose wet avalanches and natural cornice falls during periods of strong solar radiation and/or daytime warming.
Avalanche Problems
Cornices
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 3 - 5
Storm Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 3
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely
Expected Size: 3 - 6