Backcountry Avalanche Advisory for the Areas adjacent to the Whistler-Blackcomb ski area for Dec. 18, 2002
While there is finally an abundance of new snow in the mountains, the snowpack is still limited and there is considerable cause for caution for the backcountry skier.
Prior to Dec. 10 there was barely enough snow for winter travel in the mountains. The snowpack, where it existed, was frozen relatively solid with a hard surface crust, rain runnels, and a thin layer of facets. Over the following week the snowpack grew quickly as a series of warm moist storms pasted our area.
This storm snow accumulation resulted in deep depositions of stiff slab on north aspects. These slabs are up to two metres deep and average at just under one metre. These slabs have been reactive to skiers and explosives when tested. They are propagating easily, and widely, and are running fast and far. The debris is accumulating in the rocks, gullies and other terrain traps not yet filled in the slide paths and bottoms of runouts.
The snowpack structure is basically comprised of the Dec. 10 crust buried under a thin layer of loose soft snow that is covered by a weak wind slab and then the stiff storm snow slab. There are variations in the stiffness of the storm snow that have also produced avalanche activity, however, the sandwich of weak loose snow between the old crust and the storm slab is the main concern.
While the hazard exists mainly on north through northeast aspects, and above 1,900 metres, that is also where most of the good skiing is right now. The avalanche danger rating for the backcountry adjacent to the Whistler-Blackcomb ski areas on the morning of Dec. 18, 2002 is "Considerable".
Rapid weather and snowpack changes result in changes in stability and hazard. Keep up to date by dialing 604-938-7676 or contact the Canadian Avalanche Association for up to date advisories. Finally, don't forget that while the need to ski or board is strong right now, the snowpack will continue to grow and it is never a good idea to get injured because you were hasty. The current terrain hazards warrant a cautious approach to line selection, otherwise you may not get a chance to nail the sweet lines that will form as things fill in.
Blackcomb Snow Safety