Avalanche Forecast

Archived

Mar 8th, 2024–Mar 9th, 2024

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

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

We are at the higher end of Considerable Avalanche Danger. It is uncertain how the persistent weak layer will react to the warm temperatures, possibility of strong solar radiation and strong to extreme winds but I wouldn't want to be under or on any terrain of consequence to find out.

Confidence

Moderate

Avalanche Summary

Avalanches triggered from strong solar radiation have been occurring. One with large propagation near Observation Sub Peak - just south of the Jasper forecast region.

Snowpack Summary

Winds have increased in speed from the southwest and is blowing snow around in the alpine and into the tree line likely creating wind slabs. A layer of faceted snow above a 1-3cm thick crust that is down 35-60 cm. This persistent weak layer is consistently reactive in snowpit tests and is not going away anytime soon. The mid-pack is faceted with basal depth hoar and well developed facets near ground. HS ranges from 80 to 150cm.

Weather Summary

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

Saturday

Cloudy with sunny periods and isolated flurries.

Snow: 5 cm.

Alpine temperature: High -2 °C.

Ridge wind SW: 20 km/h gusting to 70 km/h.

Freezing level: 1900m

Sunday

Cloudy with scattered flurries.

Snow: 5 cm.

Alpine temperature: Low -9 °C, High -6 °C.

Ridge wind SW: 20 km/h gusting to 60 km/h.

Terrain and Travel Advice

Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Problems

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.

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.