A pair of storm systems arriving Friday and Saturday evenings will bring rapid and intense snow loading. Expect the creation of reactive storm slabs.
Early season conditions still exist, especially below treeline, and there are plenty of lurking hazards just below the surface.
Friday evening will bring with it rapid snowfall accumulation. Reactivity for easily triggered avalanches is expected to increase sharply. More snow forecasted on Saturday will add to this problem.
In the last 48 hours, there have been several size 1 to 2 avalanches that triggered naturally and with the use of ski cutting and explosives. These were in the alpine and on various aspects.
The arrival of new snow Friday evening is expected to bring increased activity.
There are few people reporting in the MIN and therefore our observations of the backcountry are minimal but it is suspected that similar natural avalanches have occurred.
At treeline and above, Friday night's snow will be falling on stubborn wind slabs that overlie a generally weak and faceted snowpack.
In sheltered areas, new snow will be sitting on the 10 cm that fell earlier this week. This covers mainly a surface hoar layer in most areas. In areas with a solar aspect, the underlying surface is a host of sun crusts while in other areas it is sitting on a weak faceted snow surface (created by recent cold temperatures). Near the bottom, there is a basal rain crust.
At this writing, total snowpack depths at the treeline are 45 to 75 cm, and in the alpine 65 to 125 cm.
Friday Night
Cloudy with snowfall, 15 - 20 cm accumulation, ridge wind west 20 to 30 km/h gusting to 45, alpine low of -8 C, and freezing level to the valley bottom.
Saturday
Mainly cloudy, 5 cm accumulation, ridge wind southwest 20 - 40 km/h gusting to 50, alpine temperatures -7 C.
SundayCloudy with snowfall, 20 to 30 cm accumulation, ridge wind southwest 15 km/ h and gusting to 50, alpine temperatures -5 to -10 C with freezing level to the valley bottom.
MondayCloudy with sunny periods, up to 10 cm accumulation, ridge wind west 10 - 25 km/h, alpine temperatures -8 to -16 C
More details can be found in the Mountain Weather Forecast.
