Avalanche Forecast

High -

WEDNESDAY NIGHT: Heavy snowfall with accumulations of 30-40 cm, freezing level rising to 1600 m by the morning, strong to extreme wind from the southwest.THURSDAY: 40-60 cm of snow, freezing level peaking around 1600 m in the morning then dropping to 1200 m throughout the day, extreme wind from the southwest.FRIDAY: Another 15-25 cm of snow, moderate to strong wind from the southwest, freezing level steady around 1200 m.SATURDAY: Mostly cloudy with some isolated flurries, light wind, alpine high temperatures around -5 C.

Preliminary reports from Wednesday indicate the storm was already producing small storm slabs in the first 5-15 cm of snow. The size and likelihood of these storm slabs will progressively increase throughout the storm.Last weekend, explosives produced small and large slab avalanches (size 1-2), some of which ran on the December 26 surface hoar layer.

Storm snow will rapidly accumulate on Thursday, with 60-100 cm of fresh snow possible by the afternoon. Rising then dropping freezing level will create an interesting mix of rain and snow at treeline and below treeline elevations.A weak layer composed of surface hoar that was buried on December 26 can be found at treeline elevations 30-50 cm below the new storm snow. This layer has shown some signs of reactivity in the past few days, and the incoming storm will definitely stress this layer.In the lower snowpack, a weak layer of sugary facets is now 150 to 200 cm deep. There have not been reports of avalanches on this layer for over a week, but it may still be reactive to heavy loads in isolated areas.