Avalanche Forecast

Fair - Due to the number of field observations

Flurries overnight combined with moderate Westerly winds and freezing levels around 800 metres. A ridge of High pressure is forecast to move over the province on Monday resulting in drier and cooler conditions. Freezing levels should drop to valley bottoms and there may be some periods of broken skies or scattered cloud. The next Pacific storm should move onto the coast sometime early Tuesday morning. Expect strong Southwest winds combined with 5-10 cm of new snow and freezing levels spiking up to about 1600 metres by the afternoon. The storm should move to the East by Wednesday leaving unsettled weather including flurries, dropping freezing levels, and light Northwest winds.

Ski cutting resulted in storm slab avalanches up to size 2.0 on Saturday, and explosives control resulted in persistent slab avalanches releasing in the storm snow and stepping down to the November 28th crust. I suspect that storm snow avalanches continued to release on Sunday with the additional load of new overnight on Sunday morning.

The new storm slab is between 40-50 cm thick above the mid-December crust/facet/surface hoar layer that extends at least up to treeline. This new storm slab has been transported by strong winds in the alpine and at treeline developing deep pockets of windslab that may not be well bonded to the old settled snow surface.  The November 28th rain crust may still be exposed in some areas due to the stripping effect of the strong Southwest winds, or it may be deeply buried down 100-150 cm. The forecast ridge of High pressure should allow for some settling and bonding of the new storm snow, except where it is sitting on a hard crust with weak surface hoar or facets at the interface. The new storm brought some snow to below treeline terrain, but it still looks like only the upper part of this elevation band has enough snow for avalanches.