Avalanche Forecast

Archived

Dec 23rd, 2022–Dec 24th, 2022

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

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.

Temperatures have moderated and we have a bit of new snow to freshen up the skiing. Be on the lookout for a building wind slab problem as the winds pick up over the weekend. Any dry loose or wind slab avalanches on the surface have the potential to trigger the deep persistent problem.

Travelers and recreationalists should be aware of the potential for intermittent Road Closures on the Icefields Parkway (93N) on Dec 25 or 26th. Check AB511 for live updates.

Confidence

Moderate

Avalanche Summary

No new avalanches have been observed or reported in the last couple days, but very few people have been out in the cold weather. Please consider submitting a MIN report if you are heading out for some holiday fun!

Snowpack Summary

5-10cm of new snow is forming fresh wind slabs. These new wind slabs sit over a heavily faceted midpack created during our recent deep freeze. The bottom of the snowpack is weak consisting of basal facets with pockets of depth hoar. The snowpack height ranges from 50-110cm. Snowpack is unsupportive tree line and below.

Weather Summary

Saturday

Periods of snow.

Accumulation: 14 cm.

Alpine temperature: High -7 °C.

Ridge wind southwest: 20-30 km/h.

Freezing level at valley bottom.

Sunday

Mainly cloudy with isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -9 °C, High -6 °C.

Ridge wind southwest: 15 km/h gusting to 50 km/h.

Freezing level at valley bottom.

Monday

Periods of snow.

Accumulation: 13 cm.

Alpine temperature: Low -10 °C, High -2 °C.

Ridge wind southwest: 20 km/h gusting to 75 km/h.

Freezing level: 1900 metres.

Terrain and Travel Advice

Uncertainty is best managed through conservative terrain choices at this time.

Problems

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.

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.

Loose Dry

Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.