Avalanche Forecast

Archived

Jan 7th, 2023–Jan 8th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

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.

Some of the signs of instability are tapering off, but we expect human triggered avalanches are still likely at Treeline and above.

Confidence

Moderate

Avalanche Summary

No new avalanches have been observed or reported in the last two days.

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

Snowpack Summary

A few centimeters of new snow around the icefields is now covering a widespread layer of surface hoar and a rain crust up to 1900m. Previous moderate to strong SW winds have formed thin wind slabs in lee features. The Dec 17th persistent weak layer is down 20-40cm in sheltered areas and remains a major concern, especially in wind loaded areas where thicker slabs are present. This all sits on the weak facets and depth hoar that make up the bottom half of the snowpack.

Click here to learn more about these tricky conditions.

Weather Summary

Sunday

Cloudy with sunny periods and isolated flurries.

Precipitation: Trace.

Alpine temperature: High -4 °C.

Ridge wind southwest: 10-30 km/h.

Freezing level: 1600 metres.

Monday

Cloudy with sunny periods and isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -9 °C, High -5 °C.

Mostly light ridge wind occasionally gusting to 35 km/h.

Freezing level at valley bottom.

Tuesday

Cloudy with scattered flurries.

Accumulation: 4 cm.

Alpine temperature: Low -11 °C, High -5 °C.

Ridge wind west: 10-20 km/h.

Freezing level at valley bottom.

Terrain and Travel Advice

Make conservative terrain choices and avoid overhead hazard.
Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.

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.

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.