Avalanche Forecast

Archived

Mar 28th, 2025–Mar 29th, 2025

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

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

With cooling temperatures surface instabilities are becoming less reactive, but persistent and deep persistent layers still exist with a large load on top of them.

Make conservative terrain decisions, and avoid exposure to overhead hazard.

Confidence

Moderate

Avalanche Summary

Road patrols on the icefields Parkway Wednesday and Thursday observed a widespread wet loose cycle to size 2 in steep terrain on all aspects, triggering persistent and deep persistent slab avalanches in some areas to size 3. Storm slab avalanches were also observed occurring on solar aspects. No observations have been made in the alpine due to poor visibility. No patrol or reported avalanches on Friday.

Snowpack Summary

10-20 cm of new snow is settling quickly. At 2200m the upper 80cm is in the process of refreezing. There is a 50-100 cm settled mid-pack over the Jan 30 facet interface. The lower snowpack is comprised of depth hoar and old crusts, and is generally weak. Snow depth at treeline is 110 - 170 cm.

Weather Summary

Saturday

Accumulation: 6 cm. Alpine temperature: High -2 °C. Ridge wind light to 10 km/h. Freezing level: 2000 metres.

Sunday

A mix of sun and cloud. Precipitation: Nil. Alpine temperature: Low -7 °C, High -2 °C. Ridge wind light to 15 km/h. Freezing level: 2000 metres.

Monday

A mix of sun and cloud. Precipitation: Nil. Alpine temperature: Low -7 °C, High -2 °C. Ridge wind light to 15 km/h. Freezing level: 2000 metres.

Terrain and Travel Advice

Make conservative terrain choices and avoid overhead hazard.
Remote triggering is a concern; avoid terrain where triggering overhead slopes is possible.

Problems

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.

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.