Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Jan 6th, 2023–Jan 7th, 2023

Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.

Regions

Northwest Inland, Kispiox, Microwave-Sinclair, Ningunsaw, South Bulkley, South Bulkley, Telkwa.

Take a cautious approach to wind-loaded areas as the ongoing strong wind may be forming fresh, reactive wind slabs.

Concern for buried weak layers warrants conservative terrain choices and avoidance of steep and convex slopes.

Confidence

Moderate

Avalanche Summary

On Thursday, as strong northeast winds redistributed the surface snow a natural size 2 wind slab was observed. This avalanche occurred as a result of rapid snow loading from wind transport. The avalanche failed on a weak layer of surface hoar, which contributed to the wide propagation of the avalanche. See full report here.

Over the last week, there were several reports of larger (up to size 2.5) natural avalanches at all elevations releasing on a 30 to 60 cm deep facet layer. Triggering an avalanche on this weak layer is still possible under the current conditions.

Snowpack Summary

Strong to extreme wind is forming drifts and wind slabs in alpine terrain and along ridges, while sheltered terrain has 10 to 15 cm of low density snow. This snow may sit above a layer of small surface hoar that will sluff easily in steep terrain. A weak layer of facets that formed during the arctic outbreak in December is buried 30 to 60 cm deep. Recent avalanche activity and snowpack tests suggest human-triggering is possible for this layer. We are uncertain about the layer's spatial distribution, but observations suggest it is fairly widespread.

Weather Summary

Friday night

Mainly cloudy with snowfall, up to 5 cm of accumulation. Alpine temperature drop to a low of -1 °C. Ridge wind southeast 35-55 km/h. Freezing level at valley bottom.

Saturday

Mainly cloudy with light flurries. Alpine temperatures reach a high of -1 °C. Ridge wind southeast 30 km/h gusting to 70 km/h. Freezing level rises to 800 meters.

Sunday

Mainly cloudy with isolated flurries. Alpine temperatures reach a high of -3 °C. Ridge wind southeast 25 km/h. Freezing level rises to 800 meters.

Monday

Mainly cloudy. Alpine temperatures reach a high of -3 °C. Ridge wind southeast 15 km/h gusting to 45 km/h. Freezing level rises to 700 meters.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Use conservative route selection and resist venturing out into complex terrain.
  • Avoid freshly wind loaded terrain features.
  • Be especially cautious near rock outcroppings, on steep convexities and anywhere the snowpack feels thinner than average.
  • Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.

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.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.