Avalanche Forecast

Archived

Mar 17th, 2025–Mar 18th, 2025

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, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

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

There is a significant volume of new snow sitting over weak old snow. These conditions are extremely challenging and one should be very suspicious of human triggering on any steep open slope.

Confidence

Moderate

Avalanche Summary

Recent regional avalanche observations typically reveal deep, wide propagations through connected terrain features, entraining debris, and traveling rapidly through elevation bands.

Snowpack Summary

Recent storms have brought a further 20-30cm adding to the previous 70-80cm since March 9th. Below this new load, the snowpack is complicated and reactive, having multiple crusts and facet layers including the deep persistent basal layer.

Weather Summary

Overnight: Clear periods. No Precip. Low -12 °C. Light winds.

Monday: A mix of sun and cloud with isolated flurries. Precipitation: Trace. High -8 °C. Light winds.

Tuesday: Sunny with cloudy periods. No Precip. Low -14 °C, High -10 °C. Light winds.

Wednesday: A mix of sun and cloud. Low -13 °C, High -8 °C. Light ridge winds. Freezing level: 1500m

Terrain and Travel Advice

Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
Make conservative terrain choices and avoid overhead hazard.

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.