Avalanche Forecast

Archived

Mar 17th, 2024–Mar 18th, 2024

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural and human triggered avalanches likely.

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.

The warming event is ongoing and won't significantly cool until Tuesday. Be patient for one more day as natural and human triggering remain likely.

Confidence

High

Avalanche Summary

Numerous loose wet avalanches occurred on many steep sunny aspects. Large slabs have been observed across Jasper running on the Feb Crust and some stepping down to ground. Saturday's explosive control work released a few size two slabs and wet loose avalanches.

Snowpack Summary

The recent dramatic warming has moistened surface snow to mountain tops on all aspects and elevations except the high north. This moist snow will have a poor overnight recovery above 2100m Sunday night and sits on the Feb 3rd crust interface down 35-60cm. This persistent weak layer has been consistently producing large natural avalanches. The equally worrisome basal depth hoar makes up the bottom third of the snowpack. HS ranges from 80 to 130cm.

Weather Summary

Mountain Weather Forecast is available @ Avalanche Canada https://avalanche.ca/weather/forecast

Monday

A mix of sun & cloud. Alpine temps: High 2 °C, Freezing level 2300-2700 metres. Ridge wind west: 10-20 km/h.

Tuesday

Mainly cloudy with isolated flurries. Alpine temps: Low -7 °C, High -4 °C, Freezing level: 1600 metres. Light ridge wind.

Wednesday

Periods of snow, 15 cm. Ridge wind east ,10 km/h.

Terrain and Travel Advice

Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

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.

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.