Environment Canada has posted weather warnings from the east coast of Vancouver Island all the way to the southeastern corner of the province, while winter storm watches are in effect for a large section of the southeast Interior and the Elk Valley.
Rainfall warnings are up for parts of Vancouver Island and the inner south coast, including Metro Vancouver, the Fraser Valley and Howe Sound.
The weather office says up to 90 millimetres of rain could cause localized flooding in low-lying areas before the system passes Tuesday.
Elsewhere, winter storm and snowfall warnings call for as much as 30 centimetres of snow over most of the Whistler area and southern Interior, including the Sea-to-Sky corridor and mountain passes of the Coquihalla and Trans-Canada highways, as well as Highway 3.
Snow is not expected to relent until early Wednesday but Avalanche Canada's website shows the risk of a slide has decreased over most of B.C., although it is ranked as high for sections of mountains across the Sea-to-Sky region and south coast.