Avalanche Forecast
Issued: Dec 17th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Loose Wet.
Avalanche Canada,
Avalanche Canada
If you find a thick, hard crust capping the snowpack, then hazard is low. Use extra caution if you find either wet snow, or dry wind-blown snow at upper elevations.
Summary
Confidence
Low
Avalanche Summary
On Sunday, shooting cracks and small slabs were triggered by riders near Mt.Arrowsmith.
On Saturday, several storm slab avalanches sized 1 to 1.5, were rider-triggered near Mt.Washington.
We expect a widespread wet avalanche cycle to occur Tuesday night during the storm, but that danger will drop rapidly, due to freezing levels returning to 1200 m by morning.
Snowpack Summary
30 to 75 mm of rain is expected to saturate the snowpack right to mountaintop overnight Tuesday. By Wednesday morning the freezing level should drop back to 1200 m and freeze the wet snow into a crust. There is a chance some late precipitation could fall as snow over the crust as the storm moves out. This would improve the riding quality, but also create potential wind slabs on north and west aspects at upper elevations. This storm is forecast to favour the southern and western parts of the Island with higher precipitation amounts.
The mid and lower snowpack is well-settled with no layers of concern.
Total snow depths at treeline vary; from 240 cm near Mt. Washington, to 140 cm near Mt Cain.
Weather Summary
Tuesday Night
Cloudy, with heavy to very heavy rain (30 to 75 mm). 80 to 100 km/h southwest ridgetop wind. Treeline temperature 6 °C. Freezing level rising to 2500 m.
Wednesday
A mix of sun and cloud. 55 to 75 km/h west ridgetop wind. Treeline temperature 2 °C. Freezing level dropping to 1200 m.
Thursday
Cloudy with with moderate to heavy rain. 80 to 95 km/h south ridgetop wind. Treeline temperature 4 °C. Freezing level rising to 2300 m.
Friday
Mostly sunny. 70 km/h south ridgetop wind. Treeline temperature 8 °C. Freezing level rising to 3200 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.
- Avalanche activity is unlikely when a thick melt-freeze crust is present on the snow surface.
- Loose avalanches may start small, but they can grow and push you into dangerous terrain.
Problems
Wind Slabs
Fresh wind slabs may have formed at upper elevation north through east aspects. Avoid steep lee slopes below ridgelines if you see recent wind affect.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
If the snow surface is wet, avoid steep terrain and overhead hazard.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 18th, 2024 4:00PM
