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

Feb 8th, 2021–Feb 9th, 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 unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.

Regions

South Coast Inland.

Recent weather patterns have resulted in a high degree of variability within the region and a single hazard rating does not fit all areas. Be vigilant about verifying conditions in your area as you travel.

Hazard in the north of the region may be one step lower at all elevations.

Confidence

Moderate - Recent weather patterns have resulted in a high degree of snowpack variability within the region. Uncertainty is due to how quickly the snowpack will recover and gain strength.

Weather Forecast

Monday night: Clear, light northwest ridgetop wind, alpine temperature -18.

Tuesday: Sunny, light northwest ridgetop wind, alpine high -15.

Wednesday: Mix of sun and cloud, light northwest ridgetop wind, alpine high -21.

Thursday: Mix of sun and cloud, light northeast ridgetop wind, alpine high -25.

Avalanche Summary

Recent snowfall focused in the Coquihalla zone has resulted in localized storm slab activity over the weekend. Natural and skier triggered avalanches averaging size 1-2 have been reported mostly on south aspects where they may be sitting over a slippery crust.

In the north of the region, recent avalanche activity has been limited to skier triggered wind slabs size 1-1.5.

Snowpack Summary

A stormy period from 4 to 8 February dropped approximately 60 cm of new snow in the Coquihalla, 40 cm near Allison Pass and 20 cm in the north of the region. This snow likely sits on a slippery crust on solar aspects, and possibly surface hoar elsewhere. Particularly in the Coquihalla, the new snow bonded poorly to these old surfaces and a number of avalanches were triggered on this layer. Looking forward, it is not clear whether the recent snow will bond, or whether this weak interface will remain a concern for several days. Given this uncertainty, a prudent approach would assume this is a suspect interface until we have more information.

An earlier persistent weak layer that formed in mid-January sits some way below the recent storm snow. This consists of facets at upper elevations, surface hoar in sheltered areas and a crust on south-facing slopes. Whumpfs were recently reported on this layer in the south of the region, indicating this layer might remain a concern there.

In the north, a melt-freeze crust from early December may be found 100 to 200 cm deep. Recent reports suggest that this layer is gaining strength and it has been unreactive in recent weeks.

Terrain and Travel

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Wind slabs may be poorly bonded to the underlying crust.
  • Be careful as you transition into wind affected terrain.
  • Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.

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.

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.