Avalanche Forecast

High -

FRIDAY NIGHT: Cloudy with light snowfall, accumulation 5 cm, moderate to strong southwest winds, alpine temperature -3 C, freezing level 1400 m.SATURDAY: Mix of sun and cloud, light southwest winds, alpine temperature -6 C, freezing level 700 m.SUNDAY: Cloudy with light snowfall, accumulation 5 cm, light to moderate southwest winds, alpine temperature -5 C, freezing level 700 m.MONDAY: Mostly cloudy, light southwest winds, alpine temperature -13 C, freezing level below valley bottom.

Evidence of a widespread natural avalanche cycle was observed on Friday. Storm slabs were reactive to skier traffic and explosives, producing large (size 2 to 3) avalanches with depths around 40 cm. A couple avalanches were observed on the deeper layers described in the snowpack summary. There will likely be further observations on what happened during the storm on Saturday as the weather clears up.

The recent storm dropped variable snowfall amounts across the region. In the north, upwards of 100 cm of snow fell. In the remainder of the region, around 40 to 60 cm of snow accumulated. The snow fell with strong westerly winds, so the deepest and touchiest deposits will likely be in lee terrain features. The freezing level rose to around 1500 m on Friday, so expect to find wet snow or a frozen crust below this elevation.All this snow is loading a weak layer that formed during the dry spell in early December. It is around 80 to 120 cm deep. The layer is composed of weak and sugary faceted snow, feathery surface hoar crystals, and on south aspects also a sun crust. The base of the snowpack is composed of weak faceted snow at alpine and treeline elevations. These basal weak layers have been producing large avalanches as recently as December 31. Human triggering any of these layers is most likely on slopes that didn't previously avalanche and on slopes that have variable snowpack depth, such as rocky alpine features.