Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Apr 13th, 2023–Apr 14th, 2023

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 unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.

Regions

Banff Yoho Kootenay, Banff, East Side 93N, Kootenay, Lake Louise, LLSA, Sunshine, West Side 93N, Field.

Natural activity has tapered since the large avalanche cycle this past week. However, human-triggered avalanches are still likely.

Confidence

Moderate

Avalanche Summary

We have just come out of an avalanche cycle to size 4 which had many full-depth avalanches that ran a long way. Avalanche control Thursday on Mt. Bosworth produced avalanches up to size 2.5. On Wednesday in Kootenay, avalanche control produced slides to size 3.5 with very wide propagations. Sunshine ski hill got a number of size 2.5 avalanches on the basal layers with explosive control.

Snowpack Summary

Recent storm snow has settled to around 30cm above 2300m. This lies over previous surfaces such as sun crusts up to ridge top and faceted layers on shady aspects. Below 2300m, surface crusts lie over a fairly isothermal snowpack due to previous rain.

Several buried crusts are in the top 50-60 cm on solar aspects. The bottom of the snowpack remains facetted and weak.

Weather Summary

Friday: As the day warms up expect convective flurries up to 5cm in some locations along the front ranges. Winds will be light from the East with freezing levels 1700-1900m.

Saturday: Starting sunny and clouding over in the afternoon. Winds will be increased from the SW and freezing levels to 2000m.

Click here for more info.

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.

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.