Avalanche Forecast

Archived

Dec 31st, 2023–Jan 1st, 2024

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, 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

Blue River, Premier, Clemina, Esplanade, North Monashee, North Selkirk, Robson, Dogtooth.

Check out this blog post for some insight into the current shallow yet complex snowpack.

Confidence

Moderate

Avalanche Summary

A large (size 3), naturally triggered deep persistent slab avalanche in alpine terrain was reported yesterday. It occurred just north of Glacier National Park.

Have a look at this blog post that highlights several recent, similar large avalanches occurring on layers deep within the snowpack.

Snowpack Summary

The upper snowpack is generally well-settled and consolidated with no significant layers of concern.

A layer of surface hoar buried in early December down roughly 50 to 90 cm remains problematic despite any recent signs of reactivity. At lower elevations, a hard crust above this layer may protect it from human-triggering.

The bottom of the snowpack is characterized by weak basal facets.

Currently, the snowpack is particularly complex, with considerable variation across different locations.

Weather Summary

Sunday night

Cloudy with no precipitation, southwest alpine winds 10 to 20 km/h, treeline temperature -5 °C.

Monday

Cloudy with no precipitation, southwest alpine winds 10 to 20 km/h, treeline temperature -6 °C.

Tuesday

Mostly cloudy with no precipitation, southeast alpine winds 10 to 20 km/h, treeline temperature -8 °C.

Wednesday

Mostly cloudy with no precipitation, south alpine winds 10 to 20 km/h, treeline temperature -6 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
Keep in mind that human triggering potential persists as natural avalanching tapers off.
Uncertainty is best managed through conservative terrain choices at this time.

Problems

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.

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.