Avalanche Forecast
Issued: Feb 20th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Storm Slabs.
lcrawley,
Avalanche Canada
Incoming snowfall amounts are uncertain.
New snow will be falling on weak layers from the dry spell. If you're seeing 20 cm or more expect avalanches to be likely.
Summary
Confidence
Low
Avalanche Summary
On Monday in the Monashees north of Revelstoke, one large (size 2.5) wind slab avalanche was triggered by the third rider on the slope. They were partially buried with their airbag exposed. Interestingly, no wind effect was felt underfoot in the start zone and the avalanche failed on a weak layer about 5 cm above the crust.
Additionally, several small and large (size 1-2) wind slab avalanches were accidentally triggered in the alpine by riders with no involvement.
Snowpack Summary
Weak layers of surface hoar and facets have grown during the long dry spell and are now getting buried.
Under the new snow, the alpine is generally wind-affected with a crust on slopes facing the sun. In sheltered terrain, 15 to 25 cm of snow overlies various layers including a weak layer of small surface hoar and/or another thin sun crust on solar aspects.
The widespread crust buried in early February is down 30 to 50 cm and has sugary facets on top. In most places, this crust is widespread up to 2400 m.
Weather Summary
Tuesday Night
Cloudy with 10 to 15 cm of snow. 10 to 20 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level 1200 m.
Wednesday
Cloudy with 5 to 10 cm of snow. 10 to 30 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1500 m.
Thursday
Mostly cloudy. 0 to 15 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1500 m.
Friday
Partly cloudy. 25 to 35 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1500 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Dial back your terrain choices if you are seeing more than 20 cm of new snow.
- Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
- Watch for fresh storm slabs building throughout the day.
Problems
Persistent Slabs
There are weak, sugary facetted crystals on the crust from early February (30-50 cm down) or just above it. This problem continues to be triggered by riders daily.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Storm Slabs
Snowfall amounts are uncertain. New snow is falling on a drought layer that includes crust on sunny slopes, sugary facets on all slopes, and surface hoar in sheltered locations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 21st, 2024 4:00PM
