Avalanche Forecast

Issued: Nov 20th, 2012 8:11AM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold.

Avalanche Canada ccampbell, Avalanche Canada

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

Summary

Confidence

3 - 139

Weather Forecast

On Wednesday expect light to moderate snowfall with freezing levels around 900m and light to moderate southerly winds. Things should dry out Wednesday night into Thursday morning before a wet and warm Pacific frontal system makes landfall. Expect moderate to heavy precipitation with freezing levels spiking to 1800m or higher on Friday.

Avalanche Summary

Recent reports from the Whistler area include several natural avalanches up to size 1.5 primarily on north through east aspects, as well as widespread whumpfing associated with facets sitting on top of the rain crust from early November. Ongoing avalanche activity is expected in alpine during stormy periods.

Snowpack Summary

Total snowpack depths at treeline range from 80cm in the Duffey Lake area to a metre in the Coquihalla. Alpine areas likely have much more that that but also highly variable depths, while most areas below treeline are below threshold depths for avalanches. The main snowpack feature in the Whistler area is a rain crust buried early November and now down around 80cm at treeline. A weak layer of facets sitting on top of 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. This weakness can likely be found in inland areas as well, however it is probably so close to the ground that any associated avalanche activity will likely be limited to slopes with smooth ground cover (e.g. scree slopes, rock slabs, summer firn, grass, etc.). For more information check out the telemarktips.com forum and the Mountain Conditions Report.

Valid until: Nov 21st, 2012 2:00PM