Regions
Kootenay Boundary.
Watch for changing conditions at higher elevations and be cautious around thin rocky areas where wind slabs could step down to deeper weak layers. Thanks to everyone who's shared observations on the MIN!
Confidence
Moderate - The weather pattern is stable
Weather Forecast
TUESDAY: Sunny with cloudy periods, light east winds, alpine temperatures around -10 C.WEDNESDAY: Sunny with cloudy periods, light east winds, alpine temperatures around -12 C.THURSDAY: Sunny, light east winds, alpine temperatures around -12 C.
Avalanche Summary
On Monday, several size 1 wind slab avalanches were skier triggered in the lee of ridgetops. Isolated natural wind slab activity in the size 1.5-2 from a few days ago was also reported. A large natural avalanche (size 2.5) was reported on a wind-loaded east facing slope in the Rossland range. This avalanche likely released on a deeper persistent weak layer.Expect wind slabs to linger on lee and crossloaded features at higher elevations.
Snowpack Summary
A variety of surface conditions exist including wind affected snow, sun crusts, shallowly buried surface hoar, and pockets of light snow. A total of 30-50 cm of settled snow now sits above a weak interface that was buried in mid-January. The interface is composed of weak facets, surface hoar, and/or sun crusts. The strength of this interface is variable, but has continued to give some sudden results and propagations in snowpack tests. Areas with thin snowpacks (e.g. less than 150 cm) have a generally weak snowpack structure with sugary facets near the ground. This includes shallow alpine slopes and most of the Rossland range. These deeper weaknesses warrant long term monitoring, as they could reawaken with a sudden change in the weather.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.