Avalanche Forecast

Archived

Dec 21st, 2025–Dec 22nd, 2025

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.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Jasper, Brazeau, Churchill, Cirrus-Wilson, Fryatt, Icefields, Maligne, Marmot, Miette Lake, Pyramid.

Avoid overhead hazard and consider staying out of avalanche terrain until the snowpack adjusts

Natural avalanche activity is likely tapering but has the potential for human triggering

Next update for Highway 93N will be provided December 22 16:00. Refer to 511 Alberta for reopening update

Confidence

Avalanche Summary

Road Patrol on Dec 21 had poor visibility and limited observations, resulting in low confidence in the alpine hazard assessment.

December 19th Avalanche control on Highway 93N produced numerous avalanches up to size 4 running fast, far and very destructive.

A natural size 4 avalanche occurred on Dec 18 along the closed section of highway 93N taking out mature timber.

Snowpack Summary

The icefields has received another 30-40cm since December 18. Moderate to strong winds continue significantly loaded lee features. The height of snow is up to 150-180 cm in wind protected areas for this zone. Snow depth is 100 cm+ in the Maligne area. Weaker facet layers are now buried deep within the snowpack.

Weather Summary

Flurries continue with 7 cm of new snow. Alpine temps near -9 °C, light ridge winds gusting to 30 km/h, freezing level at valley bottom. Monday brings cloudy skies with sunny breaks, isolated flurries, ~5 cm more snow, and gusts up to 35 km/h.

Tuesday

Tuesday will be mainly cloudy with scattered flurries bringing about 5 cm of new snow. Alpine temperatures range from -12 to -9 °C, with mostly light ridge winds occasionally gusting to 40 km/h. Freezing level remains at valley bottom.

Terrain and Travel Advice

Avoid areas with overhead hazard.
Avoid freshly wind-loaded terrain features.
Don't let the desire for deep powder pull you into high consequence terrain.

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.

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.