Regions
Kootenay Boundary.
The snow drought is over! Avalanche Danger is trending up as the new storm slab develops. It’s time to adjust your goals to reflect the increasing danger.
Confidence
Fair - Forecast snowfall amounts are uncertain on Thursday
Weather Forecast
Overnight and Thursday: 5-10 cms of snow combined with Westerly winds building to moderate values overnight. Flurries or light snow during the day accumulating another 3-5 cms. Freezing level at valley bottoms and alpine temperatures about -10.0.Friday: Another 5-10 cms is expected during the day combined with strong Westerly winds.Saturday: Continued light snowfall combined with light Westerly winds.
Avalanche Summary
Expect wind and storm slab avalanche activity to pick up with stormy weather throughout the forecast period.
Snowpack Summary
Large surface hoar growth and surface faceting continues in sheltered and shady areas, open unprotected areas are highly wind-affected, while sun-exposed slopes have been subject to melt-freeze cycles. All of these current snow surfaces will likely provide a poor bond once buried, and will be especially concerning when and where a sufficiently deep and cohesive slab develops. The persistent weakness buried early January recently produced moderate sudden planar compression test results where is was found down 45cm on a steep north facing alpine slope. However, in general, this persistent weakness is much deeper and no longer reacting in snowpack tests.
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.