Avalanche Forecast

Archived

Jan 13th, 2025–Jan 14th, 2025

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.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

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

6:25 AM Update: Travel in avalanche terrain at higher elevations is not recommended.

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.

Similar activity may occur on Tuesday.

Snowpack Summary

Around 25 to 50 cm of snow is forecast until Tuesday afternoon. 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

Monday Night

Cloudy with 20 to 50 cm of snow. Highest amounts for coastal areas, dissipating further inland. 50 to 60 km/h southwest ridgetop wind. Treeline temperature -1 °C.

Tuesday

Cloudy with 1 to 5 cm. 90 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1300 m.

Wednesday

Cloudy with 5 to 25 cm of snow, highest amounts for coastal areas, dissipating further inland. 50 km/h south ridgetop wind. Treeline temperature -1 °C.

Thursday

Cloudy with 1 to 5 cm of snow. 30 to 50 km/h northwest ridgetop wind. Treeline temperature -9 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Travel in alpine terrain is not recommended.
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

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.