New snow and extreme wind will create very dangerous conditions in parts of the region that recieve more than 25 cm of new snow. The danger will be the greatest on wind-affected slopes at upper elevations.
The incoming storm will create a variety of problems across the region. The western side of the divide could see 20-40 cm of new snow resulting in a widespread storm slab problem on steep slopes at all elevations. The eastern side of the divide will receive less snow and have a more localized problem on wind-affected slopes, especially near ridgetops.
WEDNESDAY NIGHT: Stormy weather with 10-20 cm around Pine Pass, Torpy, Kakwa, and McBride and less than 5 cm along the eastern slopes, strong to extreme wind from the southwest, treeline temperatures around -10 C.
THURSDAY: Snowfall continues with another 10-20 cm along the western slopes and less than 5 cm along the eastern slopes, strong wind from the west, treeline temperatures around -5 C with freezing level staying near valley bottom.
FRIDAY: Cloudy with isolated flurries bringing trace amounts of snow, strong wind from the west, treeline temperatures warm to -2 with freezing level quickly climbing to 1200 m in the afternoon.
SATURDAY: Mostly cloudy, strong wind from the west, freezing level climbs to 1800 m in the afternoon.
Monday's storm resulted in variable amounts of avalanche activity across the region. Reports from the McGregors where there was more snowfall suggest there were a cycle of large (size 2-3) storm slab avalanches above 1500 m, while in the drier eastern slopes of the region activity was limited to a few smaller size 1-2 wind slabs in lee terrain.
A similar pattern can be expected on Thursday with the incoming storm looking to deliver a wide range of snowfall amounts across the region.
Snowpack conditions will be variable across the region on Thursday, with 20-40 cm of new snow expected along the western slopes and only 5-10 cm along the eastern slopes. Expect widespread storm slab problems in areas with more than 25 cm of new snow. In other parts of the region you can expect strong to extreme wind to form reactive wind slabs in lee terrain.
The incoming snow is falling on heavily wind-affected surfaces above 1500 m, while lower elevations have breakable crusts near the surface. This recent MIN report describes the various hard surfaces the incoming snow is falling on.
The lower snowpack is generally strong and bonded, with one or multiple crusts near the ground. We suspect the lower snowpack could be weak in shallow rocky wind-affected slopes east of the divide.
