Sea To Sky

This bulletin is based on limited data. Local variations in conditions are likely to exist. Check out the forecaster's blog for further details on interpreting early season bulletins.

Poor - Due to limited field observations for the entire period

Friday: Moderate to heavy snowfall starting Thursday night is expected to bring 25-35cm of new snow, or more for immediate coastal areas, before tapering off by the evening. Freezing levels could spike as high as 1400m or higher, but shouldn't hover that high for very long. Mountaintop winds are expected to be extreme southwesterlies during the height of the storm. Saturday: Cloudy with isolated flurries, freezing levels around 900-1100m and light to moderate southwesterly winds. Sunday: A mix of sun and cloud, Freezing levels dropping as low as 500m and light winds.

Avalanche control on a northeast facing alpine slope with smooth ground cover in the Whistler area yesterday produced size 1 avalanches running within the recent storm snow and size 1.5 avalanches running on the early November facet/crust weakness. These persistent slabs were particularly sensitive to human triggering on slopes that had previously avalanched naturally last weekend and had since been reloaded. Natural avalanche activity followed by human-triggered activity generally occurs with every intense weather period, such as what's forecast for Thursday night and Friday.

The total snowpack depth at treeline is around a metre, The alpine snowpack is generally deeper, but likely variable with fat drifts and boney rocks, while most slopes below treeline are likely still below threshold depths for avalanches. Although weaknesses exist within the recent storm snow, the main snowpack feature is a rain crust buried early November and now down around 80cm at treeline as as deep as 1.5m in alpine areas. A weak layer of facets on top of and within this curst recently gave very easy sudden collapse compression test results as well as moderate extended column test results that propagated across the entire column. Widespread whumpfing and cracking on this layer has also been reported from the Whistler area. Because this weakness is so close to the ground in most areas, associated avalanche activity will likely be limited to slopes with smooth ground cover (e.g. scree slopes, rock slabs, summer firn, glaciers, etc.). For more information check out the telemarktips.com forum and the Mountain Conditions Report.