Regions
Kootenay Boundary.
Cold north winds have been blowing. Areas with wind slabs (south through northwest aspects) may have elevated danger.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
We're beginning to see a shift from the cold conditions of late with daytime temperatures warming up by 5-10 degrees Celcius. Only some isolated flurries possible until late Sunday when a small amount of light dry snow may fall (10-15 cms).FRIDAY: Up to 5cms light dry snow possible Thursday overnight into Friday. Mainly cloudy Friday with winds light southerly. Alpine temperatures near -14 Celcius. SATURDAY: Sunny breaks with increasing clouds overnight. Slight chance of flurries. Winds light southeasterly. Alpine high temperatures near -12 Celcius; overnight lows to -18.SUNDAY: Cloudy with flurries in the afternoon. Wind light southeasterly. Alpine high temperatures near -12 Celcius; 10-15 cms light dry snow possible overnight.
Avalanche Summary
No new avalanches reported today. Earlier in the week we had reports of several skier-triggered windslabs (Size 1.5-2) in the backcountry near Nelson. Aspects were southwest through north at treeline and in the alpine.
Snowpack Summary
On and near the surface, facets and surface hoar continue to form throughout the region, while some sun crust is found on steep solar (south) aspects. The snow from last week (30-60 cm) has been exposed to east through northerly winds during this cold clear period. In many areas "reverse loading" occurred, causing windslabs to form and giving sudden planar results in snowpack tests. The most recent snow sits over a weak layer buried on Boxing Day that was initially reactive but now appears to have gained strength. Slightly lower in the snowpack is an interface buried mid-December, now down 40-100 cm. This layer appears to be well bonded in many parts of the region giving moderate results in snowpack tests, but not reactive to skier loads.
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.