Avalanche Forecast
Regions: Kootenay Boundary.
The recent snow has added load to buried weak layers and fresh storm slabs will likely be reactive to human triggers in many areas. Conservative terrain selection is recommended.
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
THURSDAY NIGHT - Flurries, 5-10 cm / light to moderate southwest wind / alpine low temperature near -6
FRIDAY - Mainly cloudy with isolated flurries / light to moderate southwest wind / alpine high temperature near -5Â
SATURDAY - Mainly cloudy with a few flurries, up to 5 cm / light to moderate southwest wind / alpine high temperature near -6Â
SUNDAY - Flurries, 5-10 cm / moderate to strong southwest wind / alpine high temperature near -4
Avalanche Summary
With up to 50 cm of new snow sitting on potential weak layers, storm slabs are expected to be easy to trigger on Friday.
There were numerous reports of natural and explosives triggered size 1-2 storm slab avalanches on Thursday.
A few size 1 storm slab avalanches were reported in the region on Wednesday.
Snowpack Summary
25-50 cm of new snow sits on firm wind slabs in exposed areas, on a melt-freeze crust in many areas around treeline and below treeline, on a sun crust on steep south-facing slopes, and on large surface hoar in sheltered areas.
There are potentially several more layers of surface hoar in the upper snowpack, with the most notable one down about 50-70 cm. This layer was buried in early January.
A couple of crusts surrounded by weak faceted grains are buried deep within the snowpack. The upper layer is 80 to 130 cm deep and the lower one is near the ground.Â
Terrain and Travel
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
Avalanche Problems
Storm Slabs
25-50 cm of recent snow has likely formed storm slabs in many areas. These will probably be the most reactive in wind loaded areas, and in sheltered terrain where they may sit on top of a weak layer of surface hoar.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 2
Persistent Slabs
A weak layer of surface hoar that was buried in early January may become reactive with the recent new load from snow and wind.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood: Unlikely - Possible
Expected Size: 1.5 - 2.5