Avalanche Forecast

Archived

Jan 14th, 2025–Jan 15th, 2025

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Kitimat, Nass, Rupert, Seven Sisters, Shames.

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

On Monday, numerous naturally triggered slab avalanches (up to size 2.5) were reported.

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

Natural avalanche activity is expected on Wednesday and avalanche terrain should be avoided.

Snowpack Summary

20 to 50 cm of new storm snow has blanketed the region. Strong to extreme west through southwest wind has created widespread wind effect, with deeper deposits of snow on leeward slopes. A surface crust may exist up to 1000 m.

Down 50 to 100 cm a layer of surface hoar, facets, or a thin crust exists.

A persistent weak layer of surface hoar and facets overlying a crust is buried 120 to 150 cm deep. This layer remains reactive, producing large and dangerous avalanches.

Weather Summary

Tuesday Night

Snow 10 to 20 cm. 30 to 45 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level 700 m.

Wednesday

Mix rain and snow up to 15 mm. 60 to 90 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1700 m.

Thursday

Mix of sun and cloud, possible flurries. 25 to 65 km/h south ridgetop wind. Treeline temperature -2 °C. Freezing level 700 m.

Friday

Cloudy with sunny periods. 30 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.
Storm slabs in motion may step down to deeply buried weak layers and result in very large avalanches.
Keep in mind that human triggering may persist as natural avalanches taper off.

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.