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 unlikely, human triggered possible.
Regions
Banff Yoho Kootenay.
Human triggered avalanches will be likely on Sunday, and the possibility of very large natural avalanches remains possible. Stay on conservative terrain and avoid overhead exposure while the snowpack adjusts to the new load.
Weather Forecast
Continued moderate to strong westerly winds for Sunday, only trace amounts of snow, and temperatures in the -10 range at treeline. We will see a slow rising of the temperatures over the next 5 days, with valley temperatures well above freezing, and alpine temperatures approaching 0C.
Snowpack Summary
30-60cm of new snow in the past 10 days with extreme winds from the SW have created new snow slabs over a fundamentally weak snowpack comprised mostly of facets, buried wind layers, and depth hoar. We expect more avalanches on these weak facet layers over the next while as the snowpack adjusts to the load.
Avalanche Summary
Many natural, skier, and explosive triggered avalanches were observed and reported throughout the forecast region up to size 3 in the last 48hrs. Most are occurring within the storm snow, 30-60cm deep, with some "step down" avalanches in the deeper weak layers of the snowpack. These have been on many aspects and all elevations.
Confidence
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.