Avalanche Forecast

Archived

May 4th, 2024–May 5th, 2024

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Below Threshold.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Below Threshold.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Below Threshold.

Regions

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

Warm temperatures are gradually penetrating the snowpack, potentially awakening deeper instabilities.Given the high level of uncertainty in the current snowpack conditions, we advise approaching the alpine, particularly in glaciated terrain, with extra caution. Overhead hazards such as cornices should be on your radar.

Confidence

Moderate

Avalanche Summary

Jasper Visitor Safety received a second hand report of a very large slab avalanche, triggered by a cornice fall. This avalanche took place in steep glaciated terrain near Columbia Icefields and scrubbed to glacial ice with crown as deep as a few meters. Icefields parkway patrol noticed a few large wet slabs on west aspects in the Alpine. the slabs were running on old sun crusts and were most likely running within the new snow. Widespread small loose wet cycle noted in the area.

Snowpack Summary

Last weeks snow melting away below tree line and amalgamating with old snow elsewhere due to warm temperatures. Below, cornucopia of crusts up to 2600m, all aspects, and mountain top on solar aspects. Average height of snow 50-100cm. Below tree line is below threshold.

Weather Summary

Mountain Weather Forecast is available at Avalanche Canada

Sunday:

Sunny with cloudy periods. Precipitation: Nil. Alpine temperature: High 5 °C. Ridge wind light to 15 km/h. Freezing level: 2800 metres.

Terrain and Travel Advice

The likelihood of deep persistent slab avalanches will increase with each day of warm weather.

Problems

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.

Wet Slabs

Wet Slab avalanches are the release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slabs can be very unpredictable and destructive.

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.