Avalanche Forecast
Issued: Dec 13th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
swerner,
Avalanche Canada
Choose conservative terrain, weak layers in the mid and lower snowpack remain primed for human triggering.
Summary
Confidence
Moderate
Avalanche Summary
On Tuesday, numerous wet loose avalanches were reported on steep, south-facing slopes up to size 1. Explosive control was able to trigger a size 2 deep persistent slab that ran on the buried weak layer of surface hoar and facets.
Human-triggered avalanches are likely at treeline and in the alpine.
Snowpack Summary
Variable snow surfaces exist including new surface hoar development and wind affected snow. Down 30-45 cm exists a rain crust. This has been observed up to 1900 m near Golden and 2200 m near Invermere.
A concerning layer of surface hoar is now buried 40-70 cm deep.
The middle and base of the snowpack holds large, weak snow crystals. A hard crust may be found near the ground.
Treeline snowpack depths are variable and generally range between 60 and 110 cm. Snowpack tapers rapidly as you move lower in elevation.
Weather Summary
Wednesday Night
Cloudy with new snow 5-10 cm. Ridgetop wind 20-30 km/h and temperatures near -5 C. Freezing level valley bottom.
Thursday
Cloudy with a trace of new snow. Ridgetop wind 20-30 km/h and temperatures near -3 C. Freezing level near 1600 m.
Friday
A mix of sun and cloud. Ridgetop wind 20 km/h and temperatures near -2 C. Freezing levels 1500 m.
Saturday
Mix of sun and cloud. Ridgetop wind light and temperatures near -4 C. Freezing level valley bottom but an alpine temperature inversion may exist.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Stay off recently wind loaded slopes until they have had a chance to stabilize.
- Make conservative terrain choices and avoid overhead hazard.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Problems
Persistent Slabs
Surface hoar is most likely to be found at treeline elevations, and most triggerable where the rain crust (40-60 cm deep) disappears
Weak facets sit at the base of the snowpack, recent avalanches have failed on or stepped down to this layer
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
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
Valid until: Dec 14th, 2023 4:00PM
