Avalanche Forecast

Archived

Mar 18th, 2025–Mar 19th, 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.

A substantial amount of new snow has accumulated over a weak underlying snowpack, creating a tense and unpredictable situation.

These conditions pose a significant risk of human-triggered avalanches on any slope, warranting extreme caution and careful risk assessment.

Confidence

Moderate

Avalanche Summary

Widespread evidence of avalanche cycle up to size 3.5. Regionally avalanche observations are typically deep, with wide propagations.

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.

Wednesday: A mix of sun and cloud. High -6 °C. Light winds. Freezing level: 1600m

Thursday: Cloudy with Sunny periods. No Precip. Low -8 °C, High -4°C. Light winds. Freezing level: 1700m

Friday: A mix of sun and cloud. Isolated flurries. Low -9 °C, High -4 °C. Light winds. Freezing level: 1800m

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.

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.

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.