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, 2025–Dec 19th, 2025

Alpine
Natural and human triggered avalanches likely.
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 possible, human triggered probable.
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

Banff Yoho Kootenay, Little Yoho, Banff, East Side 93N, Kootenay, Lake Louise, LLSA, Sunshine, West Side 93N, Field.

Mount Stephen, Mount Field and Mount Bosworth avalanche closure areas will be closed for avalanche control December 19th

Confidence

Avalanche Summary

On December 18th avalanche control was conducted on Mount Dennis and on the Sunshine access road that achieved consistent results, running on average 3/4 of the runouts and up to size 3 in both areas. Areas at ridgetop and with significant wind affect had noticeably more pronounced propagation characteristics.

Ski Hills reported explosive results up to size 2, wind slabs, on previously controlled terrain.

Snowpack Summary

With the continued wind and snow over the past week, there is now a 50 -100 cm+ slab overlying the November crust / facet layers. These layers have been active this week with avalanches up to size 3.5, occasionally scrubbing to ground.

Below 2100m, a new crust has formed below the recent snow as the temperatures cool from the weekend warmup.

Treeline snowpack depths range from 100-180 cm!!

Weather Summary

The week of consistent snowfall continues into Friday with one more system. This one will be slightly less impactful but will still have strong to extreme west ridgetop winds and 5-15 cm of snow. A cold front will move through Fri. This will bring the heavy snow to and end across the region and winds should ease. Temps will drop behind this front, but the coldest temperatures will remain to the east of the mountain parks.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.

Problems

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.

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.