Avalanche Forecast

Moderate -

Sunday night: Clear periods. Light northwest winds.

Monday: Clear in the morning, becoming cloudy over the day with light flurries overnight. Light southwest winds, increasing over the day and becoming strong overnight. Alpine high temperatures around -12.

Tuesday: Cloudy with easing flurries and a trace of new snow, 5-15 cm with overnight accumulations, with flurries increasing again overnight. Moderate to strong southwest winds, easing over the day before increasing again overnight. Alpine high temperatures around -4.

Wednesday: Mainly cloudy with easing flurries and a trace of new snow, 5-10 cm with overnight accumulations. Light to moderate west winds. Alpine high temperatures around -5 with freezing levels rising to 1200 metres.

Saturday's reports, still hindered by visibility, gave a bit more evidence of the recent natural avalanche cycle in the Howsons, including debris from a size 3 (very large) release and more widespread debris from size 2 (large) avalanches. Road observations of the east flank of Hudson Bay Mountain showed no new avalanches.

Notably, the movement of a large snow machine managed to remote trigger a very large (size 3.5) release in the Kispiox area. This avalanche failed on the deeply buried surface hoar layer from early January, with a crown fracture of 50-200 cm deep.

Reports from Friday gave initial evidence of a natural avalanche cycle was ongoing in areas like the Howsons where up to 100 cm of storm snow accumulated. Aerial observations between the Howsons and Smithers on Friday revealed significant natural activity in avalanche tracks and runouts in spite of limited visibility.

Widespread wind and storm slabs now exist in areas where up to 50 to 90 cm recent storm snow has accumulated under the influence of strong winds. A weak layer of facets that developed in the mid-January cold snap exists beneath this recent snow. Below treeline the new snow rests on a melt-freeze crust and a well settled snowpack.

In most areas of the region, the early January surface hoar layer, now buried 150-200 cm deep, is considered dormant. It remains a more active concern in the Kispiox area and further north. Recent activity on this layer, although isolated, is noted in our avalanche summary.

A deep crust/facet layer lurks at the base of the snowpack, especially in shallower (eastern) areas that was reactive earlier in January. While it is promising that last week's snowfall did not trigger avalanches on this layer, there is some uncertainty about the possibility for avalanches in surface layers to step down to it. Triggering this layer is most likely in shallow, rocky start zones or with a large load such as cornice failure or avalanche.

• Expect slab conditions to change drastically as you move into wind exposed terrain.
• Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
• Storm slabs in motion may step down to deeper layers resulting in large avalanches.