Avalanche Canada says the warning will be in effect Saturday and Sunday.
Senior Public Avalanche forecaster James Floyer says there have been a number of recent reports of unexpectedly large avalanches in these regions.
He says the snowpack is being affected by unseasonably warm temperatures, and the warming is stressing weak layers buried deep in the snowpack.
Experienced backcountry users are recommended to stick to simple, low-angle terrain, avoid steep slopes and limit exposure to overhead hazard, while those with little or no avalanche training are asked to avoid the area.
Parks Canada also issued an avalanche warning for a large area in the Rocky Mountains, including Banff, Yoho, Kootenay and Jasper, as well as in Glacier, B.C., and in Waterton Lakes, in south Alberta.