TORONTO -- If you are heading out tonight, you may want to bring an umbrella.

Environment Canada has placed Toronto and the entire GTA under a rainfall warning in advance of the arrival of a system that could bring total rainfall amounts of 20 to 35 millimetres.

The weather agency says that the rain will begin this evening and will continue throughout the night and early morning hours before changing to snow on Saturday.

“Rainfall, combined with melting snow, is expected. The frozen ground has a reduced ability to absorb this rainfall,” the warning states.

“Be sure to clear storm drains from snow and ice to allow for proper drainage.

The temperature is expected to hover around 0 C tonight. A high of 1 C is in the forecast for Saturday.