Avalanche Forecast

Archived

Jan 11th, 2023–Jan 12th, 2023

Alpine

Natural avalanches unlikely, human triggered possible.

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.

Regions

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

Stable weather and minimal natural avalanche activity over the last few days should NOT be interpreted as an improving stability in the current snowpack. Persistent and deep persistent weak layers will be put to another test with increasing winds, warming temperatures, and additional precipitation on Friday and into the weekend.

Continue to avoid steep convexities and unsupported features. Be suspicious near open, or connected slopes. Now is not the time to let your guard down.

Confidence

Moderate

Avalanche Summary

No significant avalanche activity has been observed or reported.

If you're out in the hills, don't forget to post to the MIN. Every bit of information helps!

Snowpack Summary

Previous southwest winds redistributed any loose surface snow onto the already existing persistent slab, particularly in lee features. A layer of Surface Hoar and Facets is down 20-40cm in sheltered areas. Large Facets and Depth Hoar comprise the bottom portion of the snowpack. Snowpack depths vary from 50-100cm depending on location; in the alpine, many exposed features have been stripped to the ground.

Weather Summary

Thursday: Cloudy with scattered flurries. Accumulation: 4 cm. Alpine temperature: High -4 °C. Ridge wind southwest: 20-30 km/h. Freezing level: 1700 metres.Friday: Flurries. Accumulation: 9 cm. Alpine temperature: Low -3 °C, High -1 °C. Ridge wind southwest: 15-30 km/h. Freezing level: 2100 metres.

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

Terrain and Travel Advice

Make conservative terrain choices and avoid overhead hazard.
Keep in mind that human triggering potential persists as natural avalanching tapers off.

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.