A rainfall warning has been issued for West Vancouver Island, warning of more than 100 milimetres of rain in some areas.
Environment Canada says localized flooding in low-lying places is possible.
They also say the public should watch for possible washouts near rivers, creeks and culverts.
A frontal system over Haida Gwaii is predicted to move southwards down the B.C. Coast Monday.
A moist southwesterly flow associated with the front will cause significant rainfall amounts that will reach warning criteria over the coastal sections of the Central Coast and West Vancouver Island.