Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Dec 22nd, 2024–Dec 23rd, 2024

Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.

Regions

North Columbia, South Columbia, Esplanade, Jordan, North Monashee, North Selkirk, Dogtooth, Central Selkirk, Gold.

Be cautious as you move to higher elevations. Wind slabs may remain reactive around ridgelines, and uncertainty exists over buried weak layers.

Confidence

Low

Avalanche Summary

Multiple avalanches on the early December interface have occurred over the past four days, on west facing slopes around 2200 m. Cornice falls triggered size 3 slabs, while remotely triggered size 2 slabs were reported on a wind-affected slope at treeline. Uncertainty exists over ongoing reactivity of this layer.

Natural avalanche activity occurred over the weekend within the storm snow with the largest slabs noted from steep, wind affected terrain in the alpine.

Snowpack Summary

50 cm of wind affected snow has fallen this week, with areas in the Monashees receiving up to 70 cm. Cornices are large and fragile, with numerous cornice falls triggered by riders within the last 4 days.

A surface crust may exist from this weekend's mild temperatures. This has been observed up to 2200m near Revelstoke.

A surface hoar layer from early December is buried 50 to 90 cm and is most prevalent between 1700 to 2300 m. It may be combined with a crust and or weak facets. Large avalanches occurred on this layer on Saturday and Sunday, in northwest through southwest facing slopes above treeline.

Weather Summary

Sunday Night

Cloudy with 5-10 cm of snow. 30 to 40 km/h south ridgetop wind. Treeline temperature -5 °C. Freezing level 1300 m.

Monday

Mostly cloudy with 5 to 10 cm of snow. 20 to 30 km/h southwest ridgetop wind. Treeline temperature -4 °C.

Tuesday

Mostly cloudy with up to 5 cm of snow. 30 to 50 km/h southwest ridgetop wind. Treeline temperature -4 °C.

Wednesday

Partly cloudy. 30 to 50 km/h southwest ridgetop wind. Treeline temperature -5 °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.

Cornices

Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.

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.