Avalanche control work is planned on Thursday and Friday on the Icefields Parkway. Expect intermittent closures between 10 am and 4 pm on Thursday and a 5-hour closure between Jasper and Saskatchewan Crossing starting at 10am on Friday.
Weather Forecast
An arctic front is moving in behind Wednesday's storm. Winds will be light NW, temperatures will cool to around -10 and broken skies. We expect another cm or 2 of snow on Thursday.
Snowpack Summary
Up to 30 cm of storm snow fell on Wednesday. Below tree line, this new unconsolidated snow is sitting on a thin facetted snowpack. In sheltered tree line areas the storm snow is sitting on a supportive mid-pack. In wind exposed tree line and alpine areas, a 30-50 cm deep soft wind slab has formed on the previously faceted surface.
Avalanche Summary
Visibility was poor today but numerous size 1 loose snow avalanches were observed on steep slopes and in gulleys below tree line. These avalanches started in the storm snow and seem to step down to ground involving the weak facet snowpack. No slab avalanche activity has been observed.
Confidence
The weather pattern is stable
Problems
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.
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.