Avalanche Forecast
Issued: Dec 11th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
zryan,
Avalanche Canada
Make conservative terrain choices. Recent storm snow and buried weak layers may be primed for human triggering at treeline and above.
Summary
Confidence
Moderate
Avalanche Summary
On Sunday near Revelstoke, numerous human and explosive-triggered size 1 to 2 storm slabs were reported from northeast aspects in the alpine and treeline. In the Esplanades, skiers remote-triggered two persistent slab avalanches (size 1 and size 2) in alpine terrain.
Natural avalanche activity has tapered, but human-triggered avalanches remain likely at higher elevations. Consider the potential for remotely-triggering slopes above and adjacent to you.
Snowpack Summary
The recent 30 to 50 cm of storm snow has likely been redistributed into deeper deposits on north and east-facing slopes at higher elevations. This sits over a rain crust that has been observed up to 1800 to 2200 m throughout this region.
A concerning layer of surface hoar is now buried 60 to 90 cm deep. A widespread natural cycle may have destroyed this layer in steep features but it likely still lingers unaffected features.
The lower snowpack is a mix of rounded and faceted grains. A hard crust may be found near the ground.
Treeline snowpack depths are variable and generally range between 60 and 100 cm. Snowpack tapers rapidly as you move lower in elevation.
Weather Summary
Monday night
Clearing. Alpine wind light and variable. Treeline temperature around -7 C.
Tuesday
Mainly sunny with valley cloud. Alpine wind light from the southwest. Treeline temperature around -2 C.
Wednesday
A mix of sun and cloud. Alpine wind 40 to 90 km/h from the southwest. Treeline temperatures around -2 C with the potential for an above freezing layer to develop in the alpine.
Thursday
Cloudy with snowfall, 5 to 10 cm of accumulation. Alpine wind 15 to 40 km/h from the southwest. Treeline temperature around -5 C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Use conservative route selection and resist venturing out into complex terrain.
- Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
- Stay off recently wind loaded slopes until they have had a chance to stabilize.
Problems
Wind Slabs
Recent winds have built deeper and more reactive slabs in north and east-facing terrain features.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Buried surface hoar is most likely to be found at treeline elevations, and most triggerable where the recent rain crust thins, or disappears.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 12th, 2023 4:00PM
