Avalanche Forecast

Archived

Jan 26th, 2025–Jan 27th, 2025

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

Kitimat, Nass, Rupert, Seven Sisters, Shames, Howson.

It's uncertain if warm weather will cause weak layers in the snowpack to become reactive.

Take a conservative approach until conditions are clear.

Confidence

Low

Avalanche Summary

Saturday: Two large (size 2) cornices failed on northwest facing slopes north of Terrace.

Friday: A few small storm slabs were rider-triggered near Shames on a south aspect at treeline.

Snowpack Summary

15 to 30 of settling snow from earlier this week sits on either old wind-affected layers or possibly surface hoar in sheltered spots. In exposed areas, soft snow has been redistributed into wind slabs.

100 to 200 cm deep in the snowpack are layers of crust, facets, and possibly surface hoar that were buried in December. Warm temperatures are expected to increase the reactivity of this layer.

The lower snowpack is generally well-settled and unconcerning.

Weather Summary

Sunday Night

Clear skies. 20 to 40 km/h northwest ridgetop wind. Treeline temperature -4 °C.

Monday

A mix of sun and clouds. 20 to 40 km/h west ridgetop wind. Treeline temperature -1 °C with a temperature inversion.

Tuesday

Cloudy with 5 to 10 cm of snow. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -3 °C inversion ends.

Wednesday

Cloudy with 10 to 20 cm of snow overnight and 5 to 10 cm during the day. 30 to 50 km/h southwest ridgetop wind. Treeline temperature -5 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be especially cautious as you transition into wind-affected terrain.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Be aware of the potential for large avalanches due to buried surface hoar.
Avoid travelling on slopes below cornices.

Problems

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.

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.

Cornices

Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.