Avalanche Forecast

Archived

Mar 18th, 2024–Mar 19th, 2024

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural and human triggered avalanches likely.

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.

Tuesday will be much cooler which helps with improving overall stability but another cold front storm is coming. Potentially up to 25cm in the region Wednesday to Thursday may increase the overall hazard depending on how the storm evolves.

Confidence

Moderate

Avalanche Summary

The past three days have had numerous loose wet avalanches on steep sunny aspects plus large slabs running on the Feb Crust with some stepping down to ground. Saturday's explosive control work released a few size two slabs and wet loose avalanches. Relatively less activity was noted in Maligne lake area.

Snowpack Summary

The recent dramatic warming has moistened surface snow to mountain tops on all aspects and elevations except the high north. The moist snow sits on the Feb 3rd crust interface down 35-60cm. 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

Tuesday will bring flurries, -2 °C, and light winds. Expect flurries on Wednesday and potentially 12cm of snow, light winds, and 2000 metre freezing level. Another 7cm on Thursday, and -16 to -10 °C. Friday could be -18 to -9 °C.

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.