A thick crust in place means that avalanche problems are mainly confined to the upper snowpack. This forecast is based on 5 to 10 cm Friday Night, but if we wake up with more than 15 cm Saturday morning bump each danger rating up one level and keep the terrain choices in check.
Storm slabs will begin to form above a widespread crust. Although not expected to be a long term problem, storm slabs may be fast and very sensitive to natural and human triggering Saturday. The best bet is to scale back the terrain choices as the storm snow begins to stack up throughout the day.
A bit of storm snow Friday Night into Saturday, and then clear skies through the rest of the forecast period.
FRIDAY NIGHT: Freezing level at valley bottom, moderate to strong southwest wind, 5 to 10 cm of snow.
SATURDAY: Overcast, freezing level near valley bottom, light to moderate northeast wind, 5 to 8 cm of snow.
SUNDAY: Clear skies, freezing level rising to 1000 m, light to moderate wind generally out of the west, no significant precipitation expected.
MONDAY: Clear skies, freezing level rising to 1000 m in the afternoon, light northwest wind, no significant precipitation expected.
Loose dry avalanches to size 1 were observed Thursday from extreme terrain, but aside from that, no significant avalanche activity has been reported since last weekend. A natural avalanche cycle during last weekend's storm included some large (size 2.5) deep persistent slab avalanches in the Elk Valley (see photos in this MIN report) that appear similar to avalanches in that area in mid-January, which suggests the deep persistent slab problem will continue to resurface during stormy periods.
Variable amounts of wind affected snow sits above a widespread rain crust that exists up to roughly 2100 m. The Elk Valley has 5-15 cm of snow above the crust and the eastern slopes have 15-30 cm above the crust. There have been observations of surface hoar forming in the Elk Valley previous to Friday Night's storm, check that out here. A well consolidated mid-pack overlies generally weak basal facets, that may be possible to trigger in isolated shallow rocky start zones.
