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 7th, 2021–Dec 8th, 2021

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

Regions

Cariboos.

Conservative terrain decisions are strongly recommended due to new snow, wind, and uncertainty about the strength of the snowpack.

Confidence

Moderate - Uncertainty is due to limitations in the field data. A small change in the upper snowpack could dramatically change avalanche conditions.

Weather Forecast

A cold front will bring gusty winds and 15-40 cm of low density snow on Wednesday.

TUESDAY NIGHT: Cloudy with flurries bringing 15-25 cm of low density snow, strong with from the southwest with gusts to 80 km/h, treeline temperatures around -10 C.

WEDNESDAY: Flurries easing throughout the day with another 5-15 cm of low density snow, cloudy skies, strong wind from the west with gusts to 80 km/h, treeline temperatures around -10 C.

THURSDAY: Cloudy with light flurries and no significant precipitation, moderate to strong wind from the west, treeline temperatures around -12 C.

FRIDAY: Cloudy with light flurries bringing up to 5 cm of snow, strong wind from the southwest, treeline temperatures around -10 C.

Avalanche Summary

While reports are limited, there have been two human triggered slab avalanches over the past few days. 

One was a size 2 avalanche triggered in a north-facing bowl in Barkerville on the weekend. This avalanche is suspected to have occurred on a 50 cm deep surface hoar layer that our field team also observed in that area.

The other was triggered on Monday near McBride and from the photos in this MIN report released on a steep rocky slope near treeline. The failure layer is unknown, but could be the early season crust/facet layer. This layer was the culprit in a few very large (size 3) naturally triggered avalanches in the Valemount - Blue River corridor last week. While this layer likely needs a heavy trigger like a cornice collapse, human triggering may be possible on thin rocky slopes.

Snowpack Summary

With 15-40 cm of fresh snow in the forecast, we can expect a total of 30-60 cm of low density from the past week. The surface snow should remain loose in sheltered terrain, but with strong winds in the forecast, we expect extensive blowing snow and the formation of fresh wind slabs at upper elevations. At elevations below 1800 m, this snow sits above a crust, and there is some concern about the bond of the snow to this crust. 

An early season crust layer with some weak snow around it can be found 100-250 cm deep in the alpine, but may be more shallowly buried in some areas. See the Avalanche Details for some suspicious activity involving this layer. There is also evidence of a weak layer of surface hoar 50 cm deep in the Barkerville area. 

Extra caution should be taken at this time with uncertainty about these buried weak layers and the added load of the new snow.

Terrain and Travel

  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Avoid areas where the snow feels stiff and/or slabby.
  • Be alert to conditions that change with elevation and wind exposure.

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.

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.