Avalanche Forecast

Archived

Jan 28th, 2023–Jan 29th, 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 unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

10-20 cm of light new snow arrived Jan 27th with cold temperatures and North winds are reverse loading terrain. Allow the snowpack to adjust to these changes.

Confidence

Moderate

Avalanche Summary

No field patrol occurred on Saturday and nothing new reported. Wednesday-Thursday snowballing and loose wet activity was noted on steep west aspects near Weeping Wall. Thursday a large avalanche was observed in the Icefields starting in the Alpine, running on deep facets, and travelled far below treeline.

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

Snowpack Summary

10 to 20cm of new snow from Jan 27th overlies a melt-freeze crust up to 2000m. Steady moderate north winds at ridge top are creating windslabs. Generally, the bottom is a weak facetted snowpack. The snowpack ranges from 50 to 120cm.

Weather Summary

Sunday is to be cold, clear, and dry. Monday - Wednesday will bring clouds and sun, slightly warmer temperature, and light to moderate Northerly winds.

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

Terrain and Travel Advice

Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
If triggered, loose dry avalanches may step down to deeper layers resulting in large avalanches.

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.