New snow and strong southwest winds are forming reactive wind slabs in lee terrain features at upper elevations. A shallowly buried crust offers a slick bed surface for avalanches.
New inputs of snow amid strong southwest winds are forming fresh wind slabs in lee features at upper elevations. Wind slabs may sit over previously wind affected surfaces, directly over a crust, or over a layer of surface hoar 5-20 cm above the crust. The crust offers a slick bed surface for avalanches.
Monday night: Partly cloudy, wind increasing to moderate southwest, freezing level valley bottom.
Tuesday: 5-10 cm new snow, strong southwest ridgetop wind, alpine high -8, freezing level 500 m.
Wednesday: Partly cloudy, moderate southwest ridgetop wind, alpine high -6 C, freezing level 700 m.
Thursday: 5-10 cm new snow, moderate southwest ridgetop wind, alpine high -5 C, freezing level 900 m.
Over the last week, avalanche activity has been limited to size 1 skier triggered storm/wind slabs running on the crust. This great MIN from Friday near Nelson includes a photo of an accidental wind slab.
Please submit your observations to the Mountain Information Network (MIN). Photos are especially helpful! Thank you so much for all the great MINs submitted so far!
5-10 cm of new snow falls on a layer of surface hoar 5-20 cm above a crust. At upper elevations, strong southwest wind is blowing the new snow into fresh wind slabs amongst previously wind affected surfaces.
The early November crust is sitting about 10-30 cm up from the ground. There is a late November crust in the midpack in some places as well. Uncertainty with these crusts exist due to limited observations, but there haven't been any recent avalanches reported on these layers in this region.
Snowpack depths vary with elevation, treeline averages between 50-100 cm.
