Fresh storm slabs are expected to be most reactive in wind loaded lees at upper elevations, and where new snow falls on a melt freeze crust on south aspects or surface hoar in very wind-sheltered areas around treeline.
New snow and wind are forming storm slabs which we are expecting to be especially reactive:
In the north of the region (e.g., Duffey Lake), there is potential to trigger a weak layer of sugary faceted grains around a hard melt-freeze crust near the base of the snowpack. Although we haven't seen avalanches on this layer since last weekend, the most likely terrain features of concern are where the ground cover is smooth, such as on scree slopes, rock slabs, or glacial ice.
Sunday night: 5-10 cm new snow. Moderate to strong southwest wind, freezing level 1000 to 1300 m.
Monday: 5-10 cm new snow. Moderate southwest wind, freezing level 1100 m.
Tuesday: Clear, light northwest wind, freezing level 700 m.
Wednesday: Clear, light southerly wind, freezing level 1000 m with an above freezing layer 1500 to 3500 m.
Monday we're expecting storm snow avalanches size 1-1.5 especially in lee features where wind is depositing fatter pockets of snow, or on south aspects where the new snow may be falling on a thin melt-freeze crust.
The most recent report of an avalanche on the early-November layer was from November 21 near Duffey Lake. Check out this MIN for a photo.
Our eyes and ears in the mountains are limited at this time of year and may continue this winter due to fewer professional observations. If you see anything (or don't) while out in the field, please consider sharing via the Mountain Information Network (MIN). Photos are especially helpful! Thank you so much for all the great MINs submitted so far!
10-20 cm of new snow falls ontop of wind affected surfaces in the alpine, a thin melt-freeze crust on south aspects, and possibly surface hoar in wind sheltered areas around treeline (observed in the Coquihalla area). Moderate to strong southwest winds will likely load the falling snow into pockets of potentially reactive storm slab in lee features at upper elevations.
The lower snowpack is characterized by a few crusts formed during warm periods over the last month.
