Avalanche Forecast

Moderate - Confidence is due to a stable weather pattern with little change expected.

TUESDAY NIGHT- Clearing and cooling / Northwest wind, 20-40 km/h / alpine low temperature near -6 / freezing level valley bottom

WEDNESDAY - Cloudy with sunny breaks / northeast wind, 10-30 km/h / alpine high temperature near -4 / freezing level valley bottom

THURSDAY - Mostly sunny / northeast wind, 10-20 km/h / alpine high temperature near -8 / freezing level valley bottom

FRIDAY - Sunny / northeast wind, 15-30 km/h / alpine high temperature near -9 / freezing level valley bottom

On Monday in the Ningunsaw area, explosives triggered an impressive size 4 persistent slab avalanche which took out mature forest, and another five size 2.5-3 avalanches in adjacent terrain. These avalanches failed on weak layer at the base of the snowpack. A handful of similar avalanches have been reported over the past week in the NW Inland forecast region. Additionally on Monday, wind slabs were reactive to skier traffic and explosives triggered wind slab avalanches to size 2.

Ongoing storms resulted in numerous avalanche cycles over the past week:

A natural avalanche cycle occurred Saturday night into Sunday morning: Storm slab avalanches to size 2.5 at treeline and above; large (size 2-3) wind slab avalanches failing in steep, lee alpine features; and small (size 1) wet-loose avalanches below treeline

Another natural avalanche cycle occurred last Thursday into Friday, large (size 2-3) storm slab avalanches were reported along highway corridors. The largest (size 3) avalanches were observed in wind-loaded start zones in the alpine and treeline, but also included below tree line avalanches to size 2 failing on unsupported features. Wet-loose avalanches to size 1.5 were reported from steep rocky slabs below tree line.

Last Wednesday there were a few natural avalanches up to size 3 and one remotely triggered size 3 persistent slab avalanche reported in the north of the region.

Last Tuesday (Jan 12), another natural avalanche cycle was reported, additionally explosives triggered numerous avalanches up to size 2.5 and people triggered a few size 1 avalanches.

And a week ago Monday, there were reports of widespread natural and explosives triggered avalanches up to size 3. The largest avalanches were reported in the north of the region where there has been more recent snow. The avalanches being reported closer to Terrace were generally in the size 1-2 range.

The Tuesday moisture pulse dumped over 25 cm in 12 hours, and storm totals of 25-50 cm. South-southwest winds quickly impacted loose snow.

This most recent storm snow overlies upwards of 150 cm of settling snow from January's successive storms. Below treeline (up to 1100 m) rain on snow produced a moist snowpack, a crust has now developed.

For the most part, the snowpack is well settled and deeper instabilities in the snow pack are of little concern. We're tracking a few uncertainties, in the Shames area, a weak layer of surface hoar has been reported in sheltered areas down around 120-180 cm. And a bit further north in the Nass/Sterling/Beaupre areas, there is potentially still concern about an older weak layer of surface hoar overlying a crust that is now roughly 180-200 cm deep. And in the far north of the region, there is concern about weak snow at the bottom of the snowpack.

• Be especially cautious as you transition into wind affected terrain.
• Continue to make conservative terrain choices while the storm snow settles and stabilizes.
• Storm slabs in motion may step down to deeper layers resulting in large avalanches.