Avalanche Forecast

Moderate - Intensity of incoming weather systems is uncertain

Tuesday: Up to 15cm of new is expected to fall by Tuesday morning in the south of the region, with only a trace of new snow in the north. Continued flurries will deliver another 10-15cm of new snow in the south on Tuesday, again with only a trace in the north. Winds will be moderate gusting to high, possibly even extreme from the southwest. Freezing levels to be around 800 metres with alpine temperatures to -3 in the south and -7 in the north.Wednesday: Continuing flurries will deliver approximately 5cm of new snow. Winds strong from the southwest. Freezing level at roughly 800 metres with alpine temperatures of -4 in the south and -9 in the north.Thursday: A second storm wave will deliver flurries and approximately 10cm of new snow to the north of the region with snowfall accumulations of up to 30cm in the south. Winds moderate gusting to extreme from the southwest. Freezing levels to 700 metres with alpine temperatures of -3 in the south, 900 metres and -8 in the north.

Continued potential exists for skier and rider triggering of wind slabs at upper elevations. The possibility of buried surface hoar in isolated sheltered areas and a possible weak bond at the storm/old snow interface also demand careful evaluation. A MIN report from Saturday in the Pemberton Icefield area neatly demonstrates the potential for wide slab propagations on wind loaded features.

Incoming snowfall on Monday will bury a layer of 3-5mm surface hoar that has been observed growing on the surface in the Duffey Lake area. Below the surface, 10-20cm of storm snow from Thursday and Friday has been redistributed in some exposed areas and added to the 30-60cm of storm snow the region has seen since December 18. In higher elevation and exposed areas, this storm snow formed wind slabs in response to southwest winds. This upper snowpack overlies a variable snow surface that formed before December 18 and includes hard wind pressed or scoured areas, old wind slabs, weak faceted snow, or surface hoar. In the Duffey Lake area, recent snowpack tests gave hard sudden results down 60 cm at the interface between the recent storm snow and old snow on rounding faceted crystals. The widespread mid-November crust is typically down approximately 1-1.5m. Snowpack tests continue to show the crust to be unreactive, but it could remain a problem in shallow alpine start zones.