Avalanche Forecast

Archived

Jan 12th, 2025–Jan 13th, 2025

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

Northwest Coastal, Northwest Inland, Boundary, Kitimat, Nass, Rupert, Seven Sisters, Shames, Stewart, Kispiox, Ningunsaw, Ningunsaw, Ningunsaw.

Choose low-angled, sheltered terrain where new snow hasn't been wind-affected.

Deep instabilities are still present and have produced recent large avalanches.

Confidence

Moderate

Avalanche Summary

Numerous naturally triggered large and very large storm slabs, wind slabs and persistent slabs, occurred across the region over the last few days.

Skiers have also reported widespread whumpfing and shooting cracks. As well as remote-triggering wind slabs.

Looking forward, we expect natural avalanche activity has tapered off, but for human triggering to remain possible to likely at upper elevations.

Snowpack Summary

Strong to extreme west through southwesterly winds have been redistributing snow, creating widespread wind effect and building deeper and more reactive deposits on lee slopes.

Last week's 40 to 80 cm of storm snow is settling with the mild temperatures. However the storm snow may be slow to bond where it sits on surface hoar, facets, or a thin crust.

A surface crust may exist below 900 -1200 m.

A persistent weak layer of surface hoar and facets overlying a crust is buried 60 to 100 cm deep in the southern parts of the region, and up to 150 cm deep in areas north of Stewart. Avalanches failing on this layer could be very large and destructive.

Weather Summary

Sunday Night

Partly cloudy with 0 to 7 cm of snow. 50 km/h west ridgetop wind. Treeline temperature -2 °C.

Monday

Cloudy with 0 to 10 cm of snow. 55 km/h southwest ridgetop wind. Treeline temperature -1 °C.

Tuesday

Cloudy with 10 to 20 cm of snow/ rain below 1300 m. Highest amounts for coastal areas, dissipating further inland. 90 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1300 m.

Wednesday

Cloudy with 4 to 15 cm of snow. 50 km/h south ridgetop wind. Treeline temperature -1 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be aware of the potential for remote triggering and large avalanches due to buried surface hoar.
Be especially cautious as you transition into wind-affected terrain.
Keep in mind that human triggering may persist as natural avalanches taper off.
Use careful route-finding and stick to moderate angled slopes with low consequences.

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.