Wind loaded features are still sensitive to human triggering and should be treated with caution. Remain aware of these slopes above your head or below you feet.
With long nights and cold temperatures on deck, be warry of getting caught out.
Happy Holidays from the Banff Visitor Safety Team!
New snow and SW winds have created small wind slabs in the alpine over the past few days. Watch for wind loading above you as these have potential for both natural and human triggering. If triggered, these wind slabs could step down to the deep persistent layer at the bottom of the snowpack.
The bottom layers of the snowpack are facetted and weak in most areas. Human triggering remains possible and this could result in a large avalanche. Given the unpredictable nature of this problem, use caution when venturing on to any steeper slope with consequence.
The wind slab problem is still sensitive to human triggering, as a party had a close call at Bow Summit.
Ski hill snow safety teams reported a few size 1-1.5 wind slabs as a result of explosives and ski-cutting work in alpine features and there was an isolated report of a natural loose dry avalanche in the alpine.
Recently formed wind slabs can be found in lee aspects at tree line and in the alpine, 5 - 20cm thick. 15-50 cm of snow sits over the Dec 5 rain crust that exists as high as 2300 m, and is more prevalent in the southern part of the forecast area. The base of the snowpack is a mix of weak basal facets and a spotty crust from late Oct. Treeline snow depths range from 50-95 cm. Many early-season hazards still exist.
An approaching system will bring increasing cloud to the Alberta Rockies. There is a chance of snow over portions of the Rockies north of Lake Louise overnight. Southwesterly ridgetop winds will persist at strong to extreme strength. The overnight low in the alpine is expected to be -20C and the alpine is forecast to hit -10C.
For more information, click Mountain Weather Forecast.
