Highway 93 is closed between Saskatchewan River Crossing and Athabasca Falls until avalanche control can take place.
Weather Forecast
Freezing levels will drop overnight and during Thursday to the valley bottom. Another 10-15cm of snow is possible overnight with light winds. Thursday gusting strong SW winds at treeline and temperatures of -5. Snow flurries will taper off in the PM
Snowpack Summary
20cm of new snow has arrived in the past 24 hours. This soft storm slab is bonding poorly to the old snow surface. The mid-pack consists of persistent slab layers intermixed with weak facets. The base is weak facets, depth hoar, and an ice crust from November. Below 2,100m the snowpack is moist and below 1,700m it is wet.
Avalanche Summary
A widespread avalanche cycle is underway on all aspects and elevations. Wet slabs and point releases are occurring below 1,800m. At higher elevations dry storm slab avalanche are running far into the valley bottom. Several class 2 avalanche were observed and larger events are also expected with deep releases.
Confidence
Freezing levels are uncertain
Problems
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.