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 18th, 2018–Dec 19th, 2018

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, 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

Northwest Coastal.

The active pattern of stormy weather is finally slowing down, but the new snow needs time to stabilize.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

TUESDAY NIGHT: 5-10 cm of snow, strong wind from the southwest, freezing level dropping to 300 m, alpine temperatures drop to -5 C.WEDNESDAY: Stormy weather starting to ease with another 3-10 cm of snow, moderate wind from the southwest, alpine temperatures steady around -5 C.THURSDAY: Cloudy with isolated flurries, light wind, freezing level dropping to valley bottom with alpine high temperatures around -7 C.FRIDAY: Storm passing across southern BC brings just 5-10 cm of snow, strong wind, and alpine high temperatures around -5 C.

Avalanche Summary

Observations have been limited over the past week due to harsh weather conditions, but with the enormous amount of snowfall there have likely been several cycles of natural avalanche activity. Several large natural avalanches (size 2-3) were reported in wind loaded alpine terrain near Stewart on Tuesday. A few smaller natural avalanches (size 1-2) were reported in steep terrain in the Shames area over the past few days.

Snowpack Summary

Over the past week an onslaught of storms has delivered 100-150 cm of snow to the region, with another 5-20 cm of fresh snow possible on Wednesday. Warm temperatures have left the surface snow moist up to roughly 1000 m, which could freeze into a crust with dropping temperatures this week. Strong wind has likely affected open terrain at higher elevations and formed thick wind deposits in lee terrain.All of this storm snow sits above an interface that was a concern during the start of the storm, but the strength of this layer has probably improved substantially over the past week. The interface is composed of surface hoar, facets, and crusts that formed during the dry spell in early December. Deeper in the snowpack, there are several crusts, including an early season crust with facets near the bottom of the snowpack.

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.