Avalanche Forecast

Archived

Jan 6th, 2024–Jan 7th, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Northwest Inland, Howson, Kispiox, Microwave-Sinclair, North Bulkley, South Bulkley, South Bulkley, South Bulkley, Telkwa.

North winds may build thin, reactive slabs at upper elevations today.

Back off if you observe any signs of instability, such as avalanches, whumpfs, or shooting cracks.

Confidence

Moderate

Avalanche Summary

There have been no recent reports of avalanches. If you are going into the backcountry, consider submitting a Mountain Information Network report.

Backcountry users have been experiencing whumpfs in the Babines, Grizzly Plateau, and around Hudson Bay Mountain. We suspect the whumpfing is from the failure of surface hoar layers that are described in the Snowpack Summary. Such observations suggest that humans could trigger avalanches where these layers remain intact.

Snowpack Summary

Up to 25 cm of soft snow exists in areas sheltered from the wind. The snow surface in wind-exposed areas is wind-stiffened or scoured back to a hard melt-freeze crust or the ground. A small amount of new snow over a hard crust is found below treeline.

Two or more preserved surface hoar layers can be found buried between 35 cm and 80 cm deep. These layers are most prominent at treeline and below treeline elevations above 1200 m, but they've also been observed in some alpine locations.

Snowpack depths at treeline vary across the region with generally deeper amounts (~150 cm) in the west and shallower (~80 cm) in the east.

Weather Summary

Saturday Night

Cloudy with trace snow, northwest alpine wind 10 to 20 km/h, treeline temperature -9 °C.

Sunday

A mix of sun and cloud with no precipitation, northwest alpine wind 10 to 20 km/h, treeline temperature -10 ºC.

Monday

Cloudy with up to 5 cm of snow possible, south alpine wind 20 to 30 km/h, treeline temperature -8 ºC.

Tuesday

Cloudy with trace snow, north alpine wind 20 to 30 km/h, treeline temperature -10 ºC.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Approach steep open slopes at and below treeline cautiously, buried surface hoar may exist.
Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
Recent wind has varied in direction so watch for wind slabs on all aspects.

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.