Continually assess the snowpack for signs of instability with dynamic weather conditions. Another 5-15 cm overnight will further add to the storm slab problem.
Storm slabs will be most reactive in localized areas with the deepest snowfall accumulations. A weak layer of surface hoar is reported 20-40 cm below recent snow. Expect storm slab reactivity to increase with elevation and exposure to the wind.
Human triggering of deep weak layers remains possible in terrain with shallow, variable snowpacks. Where supportive to riders, a melt-freeze crust may be providing a bridging effect, making it more difficult to trigger deeper layers.
A small (to size 1.5) storm slab avalanche cycle occurred early Friday morning near Kootenay Pass. A number of small storm slab avalanches have occurred over the previous week, failing on a recently buried layer of surface hoar.
Please continue to share any observations or photos on the Mountain Information Network.
Upwards of 15 cm forecast for Saturday morning will add to recent storm snow. Expect ongoing surface slab development throughout the day with forecast snow and wind. 20-40 cm of recent snow has buried a layer of surface hoar in wind-sheltered terrain, primarily at the treeline and below.
A melt-freeze crust is buried 60-90 cm. This crust ranges from 2 cm at higher elevations to 10 cm at lower elevations. Below the crust, the mid-snowpack is settled and consolidated. A weak layer of facets and a crust near the bottom of the snowpack continue to be a concern. Treeline snow depths average 160-220 cm.
Friday night
Snowfall with dropping temperatures, 5-15 cm overnight. Moderate to light south ridgetop winds. Treeline temperature below 0 C. Freezing level falling to 1500 m.
Saturday
Snowfall tapering through the day, localized 24-hr accumulations by Saturday at 4 pm up to 20 cm. Light south ridgetop winds. Treeline high temperature -1 C. Freezing level 1600 m.
SundaySnowfall increases through the day, 10 cm during the day followed by 10 cm overnight. Light to moderate south ridgetop winds. Treeline high temperature +1 C. Freezing level 1400 m.
MondayCloudy with isolated flurries. Light southwest ridgetop winds. Treeline high temperatures -3 C, freezing level below 1100 m.
More details can be found in the Mountain Weather Forecast.
