Avalanche Forecast
Issued: Dec 11th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
Parks Canada,
Avalanche Canada
Ski quality is good at the moment but be on the lookout for slab development.
A persistent weak layer made up of surface hoar or a sun crust is buried 50-70 cm deep. Remote triggering is possible in areas with a slab at or near the surface.
Summary
Confidence
Moderate
Avalanche Summary
Natural avalanche activity has tapered off with a few size 1-2.5 avalanches observed in the highway corridor in steep/extreme terrain since Sunday.
Artillery control produced excellent results on Tupper and Macdonald Sat night, with most shots producing sz 2 to sz 3 avalanches from steep start zones, running out onto valley bottom fans. Debris moved fast, likely picking up speed and mass on the buried surface hoar.
Snowpack Summary
50-70cm of storm snow sits on a sun crust on steep solar aspects. In sheltered locations, this new snow sits atop surface hoar. Strong SW winds at the end of the storm created surface slab conditions on exposed Treeline and Alpine slopes.
There is a dense, well-settled mid-pack without any significant weak layers.
The Nov 9 crust is down 1-1.5m. The base of the snowpack is comprised of several dense, melt-freeze rain crusts formed in October.
Weather Summary
A ridge of high pressure is pushed out by an incoming storm on Friday night.
Tonight: Cloudy. Alp Low -4. Light winds, Freezing level(FLZ): 600 m
Thurs: Cloudy with sunny periods. No prec. Alp high -3. Light SW winds. FLZ: 1400 m
Fri: Cloudy w/flurries. Trace precipitation. Light to Moderate SW winds. FLZ: 1200 m
Sat : Flurries, 5-10 cm. Alpine high -4 °C. Light gusting to Moderate SW winds. FLZ: 1100 m
Terrain and Travel Advice
- Be careful as you transition into wind-affected terrain.
- Keep in mind that human triggering may persist as natural avalanches taper off.
Problems
Persistent Slabs
65cm of snow and strong SW winds formed a slab that sits on a surface hoar layer in sheltered zones, and overlies a sun crust on steep, solar aspects. Rider triggered avalanches are possible where the surface hoar is reactive.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Wind slabs have formed in exposed terrain at treeline and in the alpine in recent storm snow. Use caution in this terrain if surface snow feels stiffer and is cracking around skis.
Aspects: North, North East, East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 12th, 2024 4:00PM
