Avalanche Forecast

Archived

Apr 2nd, 2025–Apr 5th, 2025

Alpine

Natural and human triggered avalanches likely.

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 possible, human triggered probable.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural and human triggered avalanches likely.

Regions

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

Up to 35 cm of new snow has fallen at the Icefields and another 10 cm may fall tonight. We are likely to see a natural avalanche cycle in the alpine tomorrow.

It's a good time to avoid all overhead hazard and stick to mellow, supported terrain.

Confidence

Moderate

Avalanche Summary

Most days this week there have been size 3 avalanches failing on the deep persistent layer. On April 2 field teams observed numerous dry loose avalanches in the new snow. In some places these loose dry avalanches stepped down to deeper layers causing slab avalanches up to size 2.5

Snowpack Summary

There is 10-35 cm of new snow at Parkers Ridge. 50 cm of new snow has been reported on top of the Columbia Icefields. This new snow sits on a crust on all but due north aspects. Surface hoar sits on top of this crust in many areas. A 50-100 cm mid-pack rests on top of weak facets. The lower snowpack consists of depth hoar and breaking down crusts. Tree line snow depth is 110-170 cm.

Weather Summary

Wednesday Overnight.

10cm new snow expected.

Thursday

A mix of sun and cloud.

Precipitation: Nil.

Alpine temperature: High -9 °C.

Ridge wind northwest: 10-25 km/h.

Freezing level at valley bottom

Friday

Sunny with cloudy periods.

Precipitation: Nil.

Alpine temperature: Low -11 °C, High -3 °C.

Ridge wind light to 20 km/h.

Freezing level: 2000 metres.

Terrain and Travel Advice

Make conservative terrain choices and avoid overhead hazard.
Even brief periods of direct sun could produce natural avalanches.
Be mindful that deep instabilities are still present in the snowpack.
Loose avalanches may step down to deeper layers, resulting in larger avalanches.
A moist or wet snow surface, pinwheeling, and natural avalanches are all indicators of a weakening snowpack.

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.

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.

Loose Dry

Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.