Environment Canada has issued a rainfall warning in Metro Vancouver.
It says a moist Pacific frontal system is expected to bring about 55 millimeters of rain starting Sunday and continuing overnight, before easing this morning.
The weather office says heavy downpours can cause flash floods, which could cause water to pool on roads and localized flooding in low-lying areas, so suggests drivers remain alert and cautious.
Meanwhile, Environment Canada says the weather system is expected to bring 15 to 20 centimetres of snow to Whistler and Squamish.