Avalanche Forecast
Issued: Dec 9th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Storm Slabs.
trettie,
Avalanche Canada
Continue to make conservative terrain choices. We are inching closer to the tipping point where persistent slab avalanches become more reactive to rider triggering. Read our newest blog to learn more about this concerning layer and how to manage it.
Summary
Confidence
Avalanche Summary
No significant avalanches were reported in the past couple days. Backcountry users continue to report whumpfing and cracking, especially when traveling at the treeline elevation.
Snowpack Summary
Southerly winds continue to redistribute new snow into wind slabs on west, north and east aspects. Up to 20 of recent snow has buried a layer of surface Hoar in sheltered terrain and a sun crust on south facing slopes.
A concerning layer of surface hoar from mid November is buried down 40 to 60cm. This layer could become more reactive as slab properties above it increase with new snow and wind.
Snowpack depths average 80-160 cm in the alpine. Below treeline elevations are now above the threshold for avalanches in many areas.
Weather Summary
Friday Night
Flurries with 5 to 10cm of new snow expected. Southerly winds increasing throughout the night, strong by early Saturday morning. Low of -7 at 1500m.
Saturday
Cloudy with 10 to 15cm of new snow. Moderate southerly winds in the morning becoming light in the afternoon. High of -2 at 1500
Sunday
Flurries in the morning bringing trace amounts of new snow and then clearing in the afternoon. High of -2 at 1500m. Light easterly winds.
Monday
Mostly cloudy with the possibility of light flurries bringing trace amounts of new snow. Light winds and a high of -9 at 1500m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
- Storm slab size and sensitivity to triggering will likely increase through the day.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
Problems
Persistent Slabs
A surface hoar layer from mid November is buried down 40 to 60cm in the region. As snow continues to fall adding load to the snow pack it is likely that this layer is approaching a tipping point where it will become more sensitive to rider triggering . Use extra caution at treeline where this layer is more prominent and look for signs of instability and stiff feeling snow.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Storm Slabs
New snow and wind will likely form new storm slabs on all aspects. The largest and most reactive storm slabs will likely be on north aspects due to southerly winds expected overnight. Don't forget that storm slabs could step down to deeper layers resulting in larger and more destructive avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 10th, 2022 4:00PM
