Avalanche Forecast

Archived

Dec 28th, 2024–Dec 29th, 2024

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 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, human triggered possible.

Regions

South Columbia, Badshot-Battle, Central Selkirk, Goat, Gold, Kokanee, Retallack, Valhalla, Whatshan.

Choose mellow terrain that is sheltered from the wind.

Uncertainty about a persistent weak layer means that it's not time to venture into steep or consequential terrain.

Confidence

Moderate

Avalanche Summary

On Friday, a large avalanche was remotely triggered on the early December layer at 2250 m on an east facing slope. See the photo below for more info and a link to the report. This layer may now be harder to trigger, but it could result in a very large, deadly avalanche.

Otherwise, numerous small to large (up to size 2) natural and rider triggered avalanches were reported in the recent snow, especially in steep terrain.

Snowpack Summary

Expect to find 40 to 80 cm of settling snow in sheltered areas, and wind slabs on lee slopes below peaks and ridgelines. On sun affected slopes, the recent snow covers a melt freeze crust.

A concerning layer of facets, crusts, and/or surface hoar is buried 60 to 120 cm. It is most likely to be a problem on north through east aspects between 1700 to 2300 m. Reports of avalanches on this layer have been intermittent, and we aren't ready to ignore it just yet.

Treeline snow depths range from 100 to 180 cm.

Weather Summary

Saturday Night

Cloudy with 5 to 15 cm of snow, possible hotspots of 25 cm or more. 10 to 25 km/h southwest ridgetop wind. Treeline temperatures -5 °C.

Sunday

Partly cloudy with up to 5 cm of snow. Light variable wind. Treeline temperature -7 °C.

Monday

Mostly cloudy with up to 2 cm of snow. 5 to 15 km/h west ridgetop wind. Treeline temperature -8 °C.

Tuesday

Mostly cloudy with 2-5 cm of snow. 5 to 15 km/h west ridgetop wind. Treeline temperature -10 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Continue to make conservative terrain choices while the storm snow settles and stabilizes.
Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
Be aware of the potential for large avalanches due to buried weak layers.

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.