Avalanche Forecast

Moderate - Timing or intensity of solar radiation is uncertain

Scattered flurries overnight with light northwest winds and freezing levels down to valley bottoms. On Tuesday, light westerly winds with light precipitation and freezing levels up to 1700 metres during the day with periods of broken skies. On Wednesday, expect 5-10 cm of new snow with moderate southwest winds and a good overnight freeze. Cloudy with freezing levels rising to 1500 metres during the day. On Thursday, continued cloudy with moderate-strong westerly winds and 10-15 cm of new snow.

On Sunday we had reports of natural cornice falls up to size 3.0 that triggered persistent slab avalanches on the slopes below, and solar triggered persistent slab avalanches up to size 2.5 in the alpine from slopes steeper than 40 degrees. On Saturday cornice fall produced avalanches to size 3 on north and northeast facing features between 2000 and 2400 m, failing on the late February persistent weak layer. Small natural storm and wind slabs were also reported on northwest, northeast and east facing slopes between 2100 and 2400 m.

Large cornices loom over many ridge lines and many are teetering on the brink of failure. Old wind slabs may remain a problem on high elevation north facing features. The make up of 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. Large triggers like natural cornice fall and explosive control work continue to initiate avalanches failing on this interface. The recent warm to cool temperatures should give the overlying slab a bit of strength, but it has yet to prove itself trustworthy. Unfortunately there's not much of a reliable pattern telling us what exact aspects are most suspect. As a precautionary measure, we recommend remaining suspicious of steep unsupported features at and above treeline.