Avalanche Forecast

Archived

Feb 27th, 2025–Feb 28th, 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 avalanches possible, human triggered probable.

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.

Intense wind loading, warming trend and recent storm snow have added much stress to the weak layers within the snowpack. Careful snowpack evaluation, cautious route-finding, and conservative decision-making is essential.

Confidence

Low

Avalanche Summary

An unreported skier triggered small slab avalanche observed in the Icefields Parkway corridor on Wednesday. Local natural avalanche activity has gradually decreased, though field teams are still finding signs of large avalanche cycle throughout the bulletin region. Serious avalanche conditions persist even if the evidence is not always visible.

Snowpack Summary

10-20 cm of well-settled storm snow from last weekend overlays faceted layers formed during the February drought. These facets sit on top of old wind slabs, crusts, or more developed facets and depth hoar. Wind effect in exposed tree line and alpine elevations. Below 1500m, warm temperatures and rain have soaked the weak snowpack.

Weather Summary

Friday:Freezing level rising to 2100 m. Mostly sunny. Winds W at 20 km/h.Weekend: A mix of sun and cloud. Moderate southwest winds at ridgetop. Freezing levels near 2200 m.

Terrain and Travel Advice

Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
Avoid exposure to overhead hazards when solar radiation is strong.
Loose avalanches may step down to deeper layers, resulting in larger avalanches.

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.

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.

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.