Regions
Banff Yoho Kootenay.
There will not be a strong freeze tonight - skies will be cloudy with some clear periods and freezing levels will only dip to approximately 2500 m. Crusts will not form well tonight and will break down early.
Weather Forecast
There will not be a strong freeze tonight. Freezing levels will only dip to 2500 m for a short period tonight and a slight temperature inversion is expected. Thurs will be cloudy with some sun alpine temps of 10-14C & showers/flurries move in overnight. Friday temperatures will drop through the day, with 5-10 cm/day forecasted for Fri/Sat & Sun.
Snowpack Summary
A solid melt freeze crust to exists up to 2400 m, a little lower on North aspects. Dry uncrusted snow with up to 10cm of settled powder exists only steeper North aspects. Isolated, small windslabs exist in leeward areas in the high alpine. Crusts will not be as strong Thursday with a lack of overnight freeze and a slight inversion forecasted.
Avalanche Summary
Several loose snow avalanches to size 2.5 pouring off cliffs with sun affect as early as 8 am.
Problems
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 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.