Issued: Jan 25th, 2024 4:00PM
Elevated winds, mild temperatures, and snowfall have led to the development of slabs at all elevation bands.
These slabs are likely to be found sitting on weak layers.
As freezing levels rise through the weekend, expect these slabs to become more sensitive to human triggering.
Wednesday: Sunshine Village avalanche control triggered a sz 2 slab with a ski cut in thin, steep SW facing terrain at 2550m this was thought to be triggered on re-loaded basal facets.
Thursday: Lake Louise avalanche control continued to work with small soft slabs sitting over facets - occasionally these have pulled deeper into the basal facets over the last few days. Bourgeau Left-hand ran sz 2.5 today with a crown though to be about 50cm deep.
Hard and soft slabs have formed due to recent warming, strong winds, and small snow inputs. These slabs may overlie two weak layers: 1) Facets from the cold snap sit 10 to 30cm deep. 2) Surface hoar or a sun crust have been found in some areas below the facets 30 to 50cm deep.
The midpack offers some strength and features two crusts that persist as high as 2350m.
The lower part of the snowpack comprises weak facets and depth hoar.
Friday freezing levels will be just above Valley Bottom as W winds increase to strong.
Freezing levels will return to VB overnight Friday as winds increase further and shift SW.
Saturday winds should diminish to strong as freezing levels rise to 1800m.
Sunday freezing levels as high as 2400m are expected as winds increase to extreme.
Scattered flurries are expected for the period.
Terrain and Travel Advice
- Avoid areas where the snow feels stiff and/or slabby.
- Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
- The likelihood of deep persistent slab avalanches will increase with each day of warm weather.
Soft and hard slabs have developed due to the recent warm temperatures, moderate to strong winds and small snow inputs. These slabs sit on facets that were produced during the cold snap in most areas and in some areas surface hoar and suncrusts have been found below these facets as well.
Aspects: All aspects.
Elevations: All elevations.
Deep Persistent Slabs
The base of the snowpack consists of weak facets, depth hoar, and the overlying crust in the midpack continues to break down. Use caution in steep terrain, large planar slopes, and thin to thick areas where initiating these slabs would be more likely.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Valid until: Jan 26th, 2024 4:00PM