Avalanche Forecast

Archived

Apr 25th, 2023–Apr 26th, 2023

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Below Threshold.

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.

In the spring, convective flurries can drop vastly different amounts of snow from valley to valley. Maintain situational awareness and change your plans if faced with unexpected weather.

Confidence

Low

Avalanche Summary

No new avalanches observed

Post avalanche observations to the MIN.

Snowpack Summary

Sun crusts on solar aspects into the alpine and a melt-freeze crust at tree line and below on all aspects. Small wind slabs in the alpine from moderate to strong SW winds and recent new snow. A layer of sun crust or facets linger in the mid-pack. The main concern is the depth hoar and basal facets at the bottom causing our deep persistent slab problem.

Weather Summary

Wednesday

Sunny with cloudy periods and isolated flurries

Precipitation: Trace

Alpine temperature: High 0 °C

Mostly light ridge wind occasionally gusting to 40 km/h

Freezing level: 2200m

Thursday

Sunny

Alpine temperature: Low -8 °C, High 0 °C

Mostly light ridge wind occasionally gusting to 40 km/h

Freezing level: 2200m

Terrain and Travel Advice

In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

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.

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.

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.