Avalanche Forecast
Issued: Jan 1st, 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.
bchristie,
Avalanche Canada
Choose slopes that are sheltered from the wind, and avoid, shallow, rocky alpine slopes.
Where wind slabs sit on a buried weak layer, large avalanches are more likely.
Summary
Confidence
Avalanche Summary
On Sunday, northwest of Pemberton, a large (size 2) skier remote avalanche was reported on a north aspect in rocky alpine terrain. This problem seems to be most active in this general area, but due to it's low-likelihood/high consequence nature, we remain wary of the rest of the forecast area.
On Friday, very large persistent slabs (up to size 3), 100-120 cm deep, were naturally triggered on Decker Mountain and Panorama Ridge in Whistler, on rocky alpine northern slopes.
Snowpack Summary
15-25 cm of recent snow may be found over a thin frozen crust up to 2000 m.
Underneath, a mix of soft snow and heavily wind-affected snow overlies a layer of poorly bonded crusts and surface hoar. These have shown sensitivity to natural and remote triggers over the last 3 days. The lower snowpack is strong and bonded.
The snowpack at treeline has been rain-saturated, and a surface crust may form soon with upcoming cooling. Total snow depths remain below average, with 60 to 80 cm at treeline.
Weather Summary
Monday Night
Increasing cloud through the night. No snow/rain expected. Light south or southeast ridgetop wind, treeline temperature around -2 °C, freezing level 1100-1400 m.
Tuesday
Cloudy. 5-7 cm of snow above 1000 m. Light to moderate southeast ridgetop wind. Treeline temperature around -1 °C.
Wednesday
Cloudy. Isolated flurries above 1200 m. Light southwest ridgetop wind. treeline temperature around -2 ° C.
Thursday
Cloudy. 10 cm of snow expected above 750 m. Light to moderate south or southwest ridgetop wind. Treeline temperature around -3 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
- In times of uncertainty conservative terrain choices are our best defense.
- Carefully evaluate steep lines for wind slabs.
Problems
Persistent Slabs
Avalanches could be bigger than expected, as some recent avalanches have propagated widely on 50 to 100 cm deep crust and surface hoar layers. Be especially cautious anywhere the snowpack is thin and/or variable.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Human-triggering will remain possible, especially on lee terrain and near ridge tops. If triggered, wind slab avalanches may step down to deeper layers, resulting in larger-than-expected avalanches.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Jan 2nd, 2024 4:00PM
