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

Microwave-Sinclair, North Bulkley, South Bulkley, South Bulkley, South Bulkley, Telkwa.

Warm temperatures up high may increase the likelihood of triggering an avalanche.

Confidence

Low

Avalanche Summary

A rider triggered a large (size 2.5) slab avalanche on a southeast alpine slope on Sunday. The slab ranged from 20 to 100 cm deep with wind loading variability. The slab may have released on the persistent weak layer described in the Snowpack Summary. See this MIN for more information.

Snowpack Summary

Recent snow has been heavily wind-affected in exposed areas. A crust exists below 1250 m, making for challenging travel conditions.

A weak layer of facets and a crust from early December is buried roughly 50 to 100 cm deep.

Weather Summary

Sunday Night

Clear skies. 30 to 50 km/h northwest ridgetop wind. Treeline temperature -3 °C with a temperature inversion.

Monday

Mostly clear skies. 30 to 40 km/h west ridgetop wind. Treeline temperature 0 °C with a temperature inversion.

Tuesday

Mostly cloudy with 1 to 2 cm of snow. 15 to 30 km/h southwest ridgetop wind. Treeline temperature -2 °C.

Wednesday

A mix of sun and cloud with 5 cm of snow overnight and 2 cm during the day. 40 to 60 km/h southwest ridgetop wind. Treeline temperature -4 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be careful with wind-loaded pockets, especially near ridge crests and rollovers.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
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.