Avalanche Forecast

Archived

Mar 15th, 2025–Mar 16th, 2025

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 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.

In many areas of Jasper, the snowpack has doubled since March 8th with 80cm of new snow. This is significant volume and if a slope did not release naturally already, one should be very suspicious for human triggering. Our neighbors in Banff park have reported a few near misses and burials.

Confidence

Low

Avalanche Summary

Saturday's Icefield patrol noted one size 2.5 across the valley from Mt Wilson. It could be recent or 48 hours old. Several loose dry solar induced size 1 were noted around the Icefield's. No Maligne patrol occurred. Friday's avalanche cycle produced many alpine avalanches up to size 3 running to treeline. These avalanches had wide propagation and connected through multiple terrain features.

Snowpack Summary

20-30cm cm arrived on Thursday which adds to our total of 70-80cm since March 9th. Below the fresh snow, the snowpack is complex having multiple crusts and facet layers. The bottom of the snowpack is facets and depth hoar.

Weather Summary

Sunday will be clouds, sun, flurries, -8 °C, and light to moderate SW winds. Monday and Tuesday will be similar but slightly less winds.

Terrain and Travel Advice

Use conservative route selection. Choose simple, low angle terrain with no overhead hazard.
Avoid exposure to overhead avalanche terrain; avalanches may run surprisingly far.

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.