Avalanche Forecast

Archived

Dec 25th, 2022–Dec 26th, 2022

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.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

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

Merry Christmas from Jasper Visitor Safety Team.

Up to 30 cm of new snow in combination with strong winds and a warming trend are a true test of our weak, faceted, snowpack. When adventuring during this holiday season, be very mindful of these changes and choose your ski lines conservatively.

Travelers and recreationalists should be aware of the potential for intermittent Road Closures on the Icefields Parkway (93N) on Dec 25 or 26th. Check AB511 for live updates.

Confidence

Moderate

Avalanche Summary

Few natural small loose dry avalanches have been observed below tree line along the Icefields Parkway corridor on Sunday.Marmot Basin reported several small stiff wind slab avalanches with good propagation on Sunday.

Snowpack Summary

10-20cm of new snow is sitting over a heavily faceted midpack formed during our recent deep freeze. Strong to moderate southwesterly winds creating hard wind slabs in wind prone areas. The bottom of the snowpack is weak and consisting of basal facets with pockets of depth hoar. The snowpack height ranges from 50-120cm. Snowpack is unsupportive at tree line and below.

Weather Summary

MondayFlurries.Accumulation: 11 cm.Alpine temperature: High -1 °C.Ridge wind southwest: 20 km/h gusting to 70 km/h.Freezing level: 1900 metres.

TuesdayCloudy with scattered flurries.Accumulation: 5 cm.Alpine temperature: Low -7 °C, High -2 °C.Ridge wind south: 10-25 km/h.Freezing level: 1600 metres.

Terrain and Travel Advice

Uncertainty is best managed through conservative terrain choices at this time.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Loose avalanches may start small but they can grow and push you into dangerous terrain.

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.

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 Dry

Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.