Environment Canada has issued a rainfall warning for Windsor-Essex.
The national weather service says showers and thunderstorms are forecast to begin this evening and will continue through at least Wednesday night.
Rainfall amounts of 50 to 60 mm are expected by early Thursday morning with higher amounts in excess of 75 mm in parts of the region that receive multiple thunderstorms.
This rainfall is due to a cold front and a moisture laden low pressure system that will arrive from the American Mid-west.
Environment Canada Meteorologist Gerald Cheng says we are looking at quite a bit of rain for Windsor-Essex.
"This system is big and it's absorbing a lot of moisture not only from the Gulf {of Mexico} but also the Atlantic {Ocean}," he says.
Cheng says it's already an unsettled day with a chance of showers and thunderstorms in the forecast.
"The real big rains will come tonight with this system and will last into Wednesday and even into early Thursday," he adds.
Rainfall warnings are issued when significant rainfall is expected.
With files from Rob Hindi