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 13th, 2020–Dec 14th, 2020

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

Regions

South Columbia.

Heightened avalanche conditions exist on wind loaded slopes at upper elevations.

 

Confidence

Moderate - Recent weather patterns have resulted in a high degree of snowpack variability within the region.

Weather Forecast

A weak frontal system arrives on Tuesday evening.

SUNDAY NIGHT: Cloudy with a trace of snow, light west wind, low temperatures around -10 C.

MONDAY: Cloudy with some light flurries, light west wind, high temperatures around -8 C.

TUESDAY: Flurries throughout the day bring up to 5 cm of snow, moderate southwest wind, high temperatures around -6 C.

WEDNESDAY: Another 5 cm of snow overnight then some clearing in the afternoon, moderate west wind, high temperatures around -6 C.

Avalanche Summary

Over the past few days there have been a few reports of small avalanches above the recently buried surface hoar and crust layers. These include several dry loose avalanches in steep terrain and a size 1 skier triggered avalanches in Glacier National Park (see the photo in this MIN report). While these avalanches have limited destructive potential, we anticipate this developing into a more concerning problem when more snow arrives.

Snowpack Summary

While there is a lot of variability in surface conditions across the region, the message is similar everywhere: assess the bond of recent snow to crusts, especially if more than 20 cm of snow is present. Most parts of the region only have 10-20 cm of snow sitting above crusts. But in areas without crusts near the surface, this snow may sit above a preserved surface hoar layer. This is most likely at higher elevations in the Selkirks.

A buried rain crust can be found in the lower snowpack (50-150 cm deep) with some reports of weak snow around this crust. While we have not seen recent avalanches on this layer, it continues to produce occasional results in snowpack tests. It may be reactive to human triggers on shallow rocky slopes in the alpine or alpine-like features at treeline.

Terrain and Travel

  • Investigate the bond of the recent snow before committing to your line.
  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.

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.