The storm snow is settling out nicely below treeline, but there's been a ton of wind over the last 72 hours and we have limited alpine observations. Factor the potential for large human triggered avalanches at above treeline into your travel plans.
Weather Forecast
Someone or something is playing with the storm switch, flipping it back and forth. Storm on, storm off, storm on. We get a brief respite Monday which may even offer a bit of sun. Another storm approaches the coast moving through the interior on Tuesday/Wednesday.SUNDAY NIGHT: Freezing level at valley bottom, light southerly breeze at most elevations with strong west wind at ridgetop, trace of snow possible.MONDAY: Broken cloud cover, freezing level at valley bottom, light southwest wind at most elevations, strong west wind at ridgetop, trace of snow possible.TUESDAY: Clear skies at dawn with cloud cover steadily increasing through the day, freezing level at valley bottom, light variable wind for most of the day, no significant precipitation expected, trace of snow possible Tuesday night.WEDNESDAY: Overcast, freezing level at valley bottom, light variable wind at most elevations with strong southwest wind at ridgetop, 1 to 5 cm of snow possible.
Avalanche Summary
On Thursday and Friday a widespread natural avalanche cycle produced avalanches that averaged size 2, but storm slab avalanches as large as size 3.5 were reported from steep alpine features. A few different cornice failure events also produced very large avalanches. One of the more interesting results occurred when a group of skiers gathered on a rocky ridgetop feature on Saturday. Their weight on the slope remotely triggered a size 2.5 storm slab avalanche on a south/southeast facing feature at 2150 m.
Snowpack Summary
Thursday and Friday's storm produced 30 to 70 cm of new snow accompanied by moderate to strong wind generally out of the south. Wind effect is widespread in the alpine as well as isolated features at treeline. A 1 to 2 mm "zipper" (melt/freeze/mist) crust under the new snow has been reported in the mountains surrounding Revelstoke. Below this the snowpack is generally strong and well settled. At the bottom of the snowpack is a crust that formed in late October which is considered dormant at this time.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.