Avalanche Forecast
Issued: Dec 14th, 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
Recent storm snow and buried weak layers may be reactive to human triggering, especially above treeline.
In times of uncertainty conservative terrain choices are our best defense.
Summary
Confidence
Avalanche Summary
On Wednesday, a few isolated wind slabs were seen up to size 1.
Several skier-triggered persistent slab avalanches up to size 2.5 were reported earlier this week. They failed on weak layers comprised of surface hoar and or facets 40-70 cm. Check out this MIN from the adjacent region. It paints a clear picture.
Human-triggered persistent slabs remain the primary concern.
Snowpack Summary
10 to 20 cm of new snow has buried old wind-affected snow, sun crusts on steep south aspects and surface hoar. Approximately 25 to 40 cm down exists 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. This layer has recently been reactive to human triggering above 2100 m.
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 100 to 150 cm. Snowpack tapers rapidly as you move lower in elevation.
Weather Summary
Thursday Night
Mix of cloud and clear. Ridgetop wind 10-15 km/h from the southwest and temperatures near -7 C. Freezing levels valley bottom.
Friday
Cloudy with sunny periods and isolated flurries 2-5 cm. Ridgetop wind 20 to 45 km/h and temperatures near -2 C. Freezing levels valley bottom.
Saturday
Mix of sun and cloud. Isolated flurries 2-5 cm. Ridgetop temperatures near -2 and freezing levels valley bottom. Possible weak alpine temperature inversion.
Sunday
Mix of sun and cloud. Ridgetop wind 15 to 25 km/h from the west and temperatures near 0 C. Freezing levels valley bottom. Alpine temperature inversion.
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.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
- Be especially cautious near rock outcroppings, on steep convexities and anywhere the snowpack feels thinner than average.
Problems
Wind Slabs
Fresh wind slabs may be reactive to human triggering, especially on northerly aspects where slopes see more loading and deeper slabs.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A persistent weak layer is down 50-80 cm in the snowpack. Large, human triggered avalanches have occurred over the past few days above treeline.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 15th, 2023 4:00PM
