Avalanche Forecast
Issued: Dec 12th, 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.
swerner,
Avalanche Canada
Reduce your exposure to avalanche terrain if the temperature is above 0°C. Make conservative terrain choices. Recent storm snow and buried weak layers may be reactive to human triggering.
Summary
Confidence
Moderate
Avalanche Summary
On Monday, in the Esplanades, skiers remote-triggered two persistent slab avalanches (size 1 and size 2) in alpine terrain. A skier-triggered wind slab size 2 was reported outside of the ski hill boundary at RMR. Check out the MIN post here.
Natural avalanche activity has tapered, but human-triggered avalanches remain possible at higher elevations, particularly where slabs sit over the weak surface hoar.
Snowpack Summary
The recent 30-40 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 to ridgeline in most areas.
A concerning layer of surface hoar is now buried 50-80 cm deep.
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 140 cm. Snowpack tapers rapidly as you move lower in elevation.
Weather Summary
Tuesday night
Mainly clear. Alpine wind 20-30 km/h from the southeast. Alpine temperatures around -1 C with an alpine temperature inversion, expected to last for 12-15 hours. Freezing level valley bottom.
Wednesday
Mix of sun and cloud. Alpine wind 15 to 30 km/h from the southwest. Alpine temperatures near -1 and the freezing level sits near 1400 m.
Thursday
Cloudy with snowfall, 5 to 15 cm of accumulation. Alpine wind 10 to 15 km/h from the southwest. Treeline temperature around -5 C. Freezing levels 1300 m.
Friday
A mix of sun and cloud. Alpine winds are light from the south with temperatures near -2 C. Freezing levels 1200 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Extra caution for areas experiencing rapidly warming temperatures for the first time.
- Use careful route-finding and stick to moderate slope angles with low consequences.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
Problems
Wind Slabs
Recent winds have built reactive wind 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 at higher elevations.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 13th, 2023 4:00PM
