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

Jan 12th, 2021–Jan 13th, 2021

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

Regions

Northwest Coastal.

The storm and associated natural avalanche activity has tapered off to some degree, but human triggered avalanches remain likely. Conservative terrain selection is recommended.

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

TUESDAY NIGHT - Mainly cloudy with a few flurries, up to 5 cm / light southwest wind / alpine low temperature near -6 

WEDNESDAY - Mainly cloudy with flurries, 5-10 cm / moderate southeast wind / alpine high temperature near -6

THURSDAY - Mainly cloudy / moderate southeast wind / alpine high temperature near -5 

FRIDAY - Flurries, 5-10 cm / moderate southwest wind / alpine high temperature near -6

Avalanche Summary

Human triggered avalanches are expected to remain likely on Wednesday, especially in wind loaded areas.

At the time of publishing, there were a few explosives triggered storm slab avalanches to size 2 reported on north aspects in the alpine, in the north of the region.

On Monday, there were reports of widespread natural and explosives triggered avalanches up to size 3. The largest avalanches were reported in the north of the region where there has been more recent snow. The avalanches being reported closer to Terrace were generally in the size 1-2 range.

There were a few natural and explosives triggered storm slab avalanches size 1-2.5 reported in the region on Sunday.

Snowpack Summary

With continued flurries Tuesday night and into Wednesday, storm slabs will likely continue to be reactive to human triggers at all elevations.

Aside from this new snow, the main concerns vary throughout the region. In the Shames area, a weak layer of surface hoar has been reported in sheltered areas down around 100-160 cm. 

A bit further north in the Nass/Sterling/Beaupre areas, there is potentially still concern about an older weak layer overlying a crust that is now roughly 160-180 cm deep. 

In the far north of the region, there is concern about weak snow at the bottom of the snowpack.

Terrain and Travel

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Avoid freshly wind loaded terrain features.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.

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.

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.