Avalanche Forecast

Archived

Dec 25th, 2024–Dec 26th, 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 unlikely, human triggered possible.

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

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

Give yourself a wide margin for error. New snow, wind and buried weak layers make a complex snowpack.

Small terrain and lower angle slopes will be safer riding.

Confidence

Low

Avalanche Summary

Avalanche activity continues in this region with numerous natural and human triggered avalanches within the storm snow, at both treeline and in the alpine. In places these have been large (up to size 2.5).

Avalanches on the early December layer continue on north, east and west facing slopes around 2200 m. This includes large remotely triggered slabs, and human triggered cornice-falls triggering slabs on the slope below.

See the photos below for examples.

Snowpack Summary

Recent snow continues to accumulate and is between 20 to 40 cm in depth. This new snow sits on a melt freeze crust on previously sun affected slopes.

Cornices are large and fragile from recent winds and mild temperatures.

A concerning layer of facets, crusts, and in some places surface hoar is buried 60 to 110 cm deep. The distribution is variable throughout this region but it is most prevalent between 1700 to 2300 m. Large avalanches occurred on this layer on Saturday and Sunday, in north through southwest facing slopes above treeline.

Treeline snow depths range from 100 to 180 cm.

Weather Summary

Wednesday Night

Mostly cloudy with 5 to 10 cm of snow. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -5 °C.

Thursday

Mostly cloudy with 10 to 20 cm of snow. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -4 °C.

Friday

Partly cloudy with flurries. 10 to 20 km/h southwest ridgetop wind. Treeline temperature -2 °C.

Saturday

Mostly cloudy with 5 to 15 cm of snow. 30 to 50 km/h south west ridgetop wind. Treeline temperatures -2 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Stay off recently wind loaded slopes until they have had a chance to stabilize.
Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Be aware of the potential for large avalanches due to buried weak layers.

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.