Environment Canada has issued a rainfall warning for Toronto and the GTA ahead of a system that is expected to dump 25 to 50 millimetres of precipitation on the region.

According to the weather agency, the rain will begin this evening and end sometime Monday afternoon.

“Heavy downpours can cause flash floods and water pooling on roads,” Environment Canada warns in a statement. “If visibility is reduced while driving turn on your lights and maintain a safe following distance.”

Environment Canada issues rainfall warnings when there is 25 or more millimetres of rain forecast to fall within 24 hours or when the ground is frozen or saturated and has a reduced ability to absorb rain.