Avalanche Forecast

Moderate - Timing or intensity of solar radiation is uncertain

Another 5-10cm of snowfall is expected Tuesday overnight with freezing levels around 500m and moderate southwest winds in the alpine. Unsettled conditions are expected for Wednesday as a ridge of high pressure builds over the coast. Cloudy conditions with light flurries are expected for the morning and a mix of sun and cloud is expected for the afternoon. Afternoon freezing levels are expected to be 500-800m and alpine winds are forecast to be light from the northwest. Sunny conditions are expected for Thursday with afternoon freezing levels around 1000m and light outflow winds in the alpine. A mix of sun and cloud is forecast for Friday with freezing levels climbing to around 1500m and moderate outflow winds in the alpine.

On Monday, a ski cut triggered a size 1 cornice release north of Stewart.  In the far north, a natural cornice release triggered a size 2.5 persistent slab avalanche on the early March surface hoar layer.  Natural sluffing was also reported from steep sun exposed slopes. On Sunday, explosives triggered several winds slabs size 1.5-3 north of Stewart.  With ongoing wind loading, wind slabs are expected to be reactive to human triggering on Wednesday.  If the sun comes out on Wednesday, cornices and lingering slabs are expected to become weak, and could even fail naturally.  Loose sluffing is expected from steep sun exposed slopes.

20-30cm of new snow has accumulated over the last couple days in sheltered areas.  Strong southerly winds have redistributed the surface snow forming wind slabs and adding mass to cornices.  On south aspects, the recent storm snow may have buried a sun crust. Lower elevations are going through daily melt-freeze cycles.  A layer of surface hoar buried on March 3 is down 70-100cm and has been recently reactive in the areas north of Stewart. An older crust/facet layer buried in early February can now be found down over a meter but this layer has been dormant for several weeks.