Avalanche Forecast
Issued: Jan 2nd, 2024 4:00PM
The alpine rating is Persistent Slabs and Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeChoose 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
Moderate
Avalanche Summary
On Monday, in the Whistler area, several small, human triggered, loose dry and storm slab avalanches were reported.
On Sunday, northwest of Pemberton, a large (size 2) skier remote avalanche was reported on a north aspect in rocky alpine terrain. There were also a few similar but larger (up to size 3), naturally triggered avalanches reported northwest of Squamish. Due the low-likelihood/high consequence nature of this problem, we remain wary of the whole forecast area.
Snowpack Summary
15-25 cm of recent snow sits on 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 human triggers in the last couple of 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
Tuesday Night
Cloudy. 2-5 cm of snow above 1100 m. Light southeast ridgetop wind becoming southwest by the morning. Treeline temperature around -1 °C.
Wednesday
Cloudy. Trace of new snow above 1200 m. Light southwest ridgetop wind. Treeline temperature around -2 ° C.
Thursday
Cloudy. 10-15 cm of snow expected above 800 m. Light to moderate south or southwest ridgetop wind. Treeline temperature around -3 °C.
Friday
Mostly Cloudy. 10-15 cm of snow expected above 500 m. Light to moderate south or southwest ridgetop wind. Treeline temperature around -7 °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. Most likely in wind loaded terrain, and 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 3rd, 2024 4:00PM