Avalanche Forecast
Issued: Feb 21st, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
cgarritty,
Avalanche Canada
Analyze wind loading patterns to navigate around deeper, more reactive wind slabs. Practice good avoidance! Some slabs may have potential to step down to a deeper weak layer if triggered.
Summary
Confidence
Moderate
Avalanche Summary
Reports from the past week show a pattern of mainly small wind slab avalanches on a range of aspects, both human and remote triggered. Slabs have averaged 20 - 30 cm thick, with some failing on buried surface hoar and propagating widely.
Looking forward, focus is shifting to more recent snow settling on a new set of problematic interfaces. There remains uncertainty about the possibility for surface avalanches to step down to the weak layers involved in recent avalanches.
Snowpack Summary
Including 5 -15 cm Tuesday night, 10-20 cm of recent snow now overlies a mix of previous surfaces that includes crust on south aspects and all aspects at lower elevation, surface hoar in sheltered features and previously wind-affected surfaces in the open. Areas where wind loading has increased the depth of new snow and where preserved surface hoar is buried are the most concerning.
30 to 40 cm of snow sits above an older layer of large surface hoar and/or faceted crystals at treeline and above. A widespread, thick crust exists 30 to 60 cm below the surface. This problematic combination remains a concern as the load above it increases.
The snowpack is well bonded and strong below this crust.
Weather Summary
Wednesday night
Cloudy with diminishing isolated flurries. 5 to 15 km/h southeast alpine wind. Freezing level steady near 1500 m.
Thursday
Mostly cloudy with scattered flurries bringing less than 5 cm of new snow. 5 to 10 km/h southeast alpine wind shifting southwest. Treeline temperature -1 C with freezing level steady around 1500 m.
Friday
Mostly cloudy with flurries beginning in the afternoon. 15 to 30 km/h southwest alpine wind. Treeline temperature -1 °C with freezing level rising to 1500 m.
Saturday
Cloudy with flurries bringing about 5 cm of new snow, including overnight amounts. 30 to 40 km/h southwest alpine wind. Treeline temperature -4 °C with freezing level to 1200 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Wind slabs are most reactive during their formation.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Problems
Wind Slabs
New snow and wind will form wind slabs near ridge crests.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
New snow has been adding to the load over weak layers from early February. Surface avalanches may have potential to step down to this layer to create a larger, more destructive avalanche.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 22nd, 2024 4:00PM
