Avalanche Forecast

Archived

Dec 24th, 2024–Dec 25th, 2024

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, 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.

Regions

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

Avoid large open slopes and wind-affected snow near ridgelines. Recent avalanches have been triggered within the recent snow, and on buried weak layers.

Confidence

Low

Avalanche Summary

Avalanche activity continues in this region with numerous natural and human triggered avalanches within the storm snow, primarily in wind loaded treeline and alpine features.

Multiple avalanches on the early December interface have occurred over the past week 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

Light amounts of snow continue to accumulate, falling on wind affected settling storm snow or a melt freeze crust on 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

Tuesday Night

Mostly cloudy with flurries. 30 to 40 km/h westerly ridgetop wind. Treeline temperatures drop to -6 °C.

Wednesday

Mostly cloudy with flurries. 40 to 50 km/h southwest ridgetop wind. Treeline temperature -5 °C.

Thursday

Mostly cloudy with 10 cm of snow. 30 to 50 km/h southwest ridgetop wind. Treeline temperature -4 °C.

Light snow continues overnight with localised hot spots of 20 cm possible in the Monashees.

Friday

Mostly cloudy with 10 cm of snow. 30 to 50 km/h southwest ridgetop wind. Treeline temperature -4 °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.