Avalanche Forecast

Archived

Jan 9th, 2023–Jan 10th, 2023

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

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.

Some of the signs of instability are tapering off, but human triggering of persistent and deep persistent slab avalanches remains possible at Treeline and above. Continue to avoid steep convexities, unsupported features, and large open tree line and alpine slopes. Although natural avalanche activity has tapered off, now is not the time to let your guard down.

Confidence

Moderate

Avalanche Summary

No significant avalanche activity have been observed or reported in the last four days. Explosive control work at Marmot Ski area triggered additional avalanches on the deep persistent problem in steep alpine terrain on Sunday.

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

Snowpack Summary

Previous moderate to strong 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 ground.

Click here to learn more about these tricky conditions.

Weather Summary

Tuesday expect variable cloud with the potential for isolated flurries. Daytime high in the valley will be -1C, low of -11C. Wind will be light from the west. Clearing on Wednesday with similar temperatures. The northern edge of a building low pressure system will bring increasing cloud on Thursday with moderate southwest winds and additional isolated flurries.

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.