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 Wind Slabs and Persistent Slabs.
wlewis,
Avalanche Canada
Wind loaded features continue to be the primary concern. Watch for dense pockets of snow around ridgelines, slabs may sit over a weak layer.
Head to sheltered areas for the best riding conditions.
Summary
Confidence
Avalanche Summary
No new avalanches have been reported on the persistent weak layer, but we've had reports of shooting cracks and whumpfing at treeline. With very few field observations, there is great uncertainty around this layer and professionals have their guard up.
On Wednesday and Thursday natural wind slabs were reported around the Pine Pass area, to size 1.5 on north and east aspects.
Thank you for all the MIN reports! They are extremely helpful to us in the early season when snowpack information is limited. Please continue to share your observations via the Mountain Information Network
Snowpack Summary
Recent snow (20-40 cm has accumulated over several days) and variable wind have formed slabs in wind loaded terrain features at higher elevations.
A weak layer of surface hoar, facets, and/or melt-freeze crust can be found down 40-70 cm. This layer is more likely to be reactive where wind distribution has created a cohesive slab over it.
Snowpack depths range from 70 cm at treeline to 140 cm in the alpine. Below treeline snowpack is thin and faceted (weak) making it a challenge to access terrain in many areas.
Weather Summary
Friday Night
Partly cloudy with moderate southerly winds, clearer skies to the north. Trace to 3 cm overnight in southern terrain. Freezing level below valley bottom.
Saturday
Mostly cloudy with flurries bringing up to 5 cm in the south. Strong southeast winds. Alpine high temperature -6.
Sunday
Mostly cloudy. Light to moderate easterly winds. Alpine high temperature -8. No snowfall expected.
Monday
A mix of sun and cloud with light northerly winds. Alpine high of -10. No snowfall expected.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
- Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
Problems
Wind Slabs
Wind slabs linger on north through east facing slopes at higher elevations. Small avalanches may trigger deeper weak layers within the snowpack.
Watch for signs of instability such as whumpfing, cracking, and recent avalanches.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A layer of concern formed in mid-November is composed of faceted grains, surface hoar, and/or a hard crust and can be found down 40 to 70 cm. Each incremental snowfall and wind event is adding an additional load bringing the weak layer closer to its tipping point. As a cohesive slab builds above the weak layer it could quickly become reactive to natural or human triggers.
Aspects: All aspects.
Elevations: Treeline.
Likelihood
Expected Size
Valid until: Dec 10th, 2022 4:00PM
