Avalanche Forecast

Archived

Feb 23rd, 2023–Feb 24th, 2023

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 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.

Regions

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

The widespread avalanche cycle along the Icefields Parkway on Tuesday and Wednesday is a good reminder to pay attention to overhead hazard and that the deep persistent problem remains a concern.

Confidence

Moderate

Avalanche Summary

Widespread avalanche cycle 24-48hrs old on either side of the Icefields Parkway on all aspects in the alpine. Mostly size 2-3 and up to size 4. Most of these avalanches started as wind slabs and stepped down to the deep persistent facet layer. Most notably the main Buck Lake slide path and the Churchill South slide path ran into the ski lines.

Don't forget to post avalanche observations to the MIN.

Snowpack Summary

Cold temperatures are faceting the upper snowpack. Wind stripped and sculpted snow in exposed locations around the Icefields. In sheltered locations 40 cm of settled snow sits on top of a generally weak mid and lower snowpack with facets and depth hoar at the base. The height of snow is variable from 60 to 160cm.

Weather Summary

For Parker Ridge

A mix of sun and cloud.

Precipitation: Nil.

Alpine temperature: High -20 °C.

Ridge wind west: 15 km/h.

Saturday

Mainly cloudy with scattered flurries.

Accumulation: 4 cm.

Alpine temperature: Low -22 °C, High -13 °C.

Ridge wind southwest: 20 km/h.

Detailed weather forecasts from Avalanche Canada: https://avalanche.ca/weather/forecast

Terrain and Travel Advice

Expect slab conditions to change drastically as you move into wind exposed terrain.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger 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.

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.

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.