Avalanche Forecast

Archived

Jan 28th, 2024–Jan 29th, 2024

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 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.

Regions

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

Closures of the Icefields Parkway for avalanche control will take place on Monday, between the Parker Ridge and Pinto Lake trailheads. No backcountry access in this area is permitted, including the Weeping Wall area and Polar Circus.

See 511 Alberta for details.

Confidence

High

Avalanche Summary

Numerous Deep Persistent and Persistent slabs have been observed over the past few days throughout the region.

Snowpack Summary

Fluctuating freezing levels with intermittent solar radiation has formed surface crusts up to 2000m on most aspects, and higher on steep sun effected ones. Persistent weak layers formed in early January are down 20-30cm in sheltered areas, and have been reactive more recently where wind loaded. Well developed facets and depth hoar make up the bottom of the snowpack.

Weather Summary

It will continue to be unseasonably warm with strong winds for the next couple days. There is also potential for some light precipitation near the icefields, likely a mix of rain or snow depending on elevation.

The Mountain Weather Forecast is available at Avalanche Canada https://avalanche.ca/weather/forecast

Terrain and Travel Advice

The likelihood of deep persistent slab avalanches will increase with each day of warm weather.
Make conservative terrain choices and avoid overhead hazard.

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.

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.

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.