Environment Canada is out with a special weather statement for much of southwestern Ontario.
The national weather agency says heavy rain is expected beginning tonight and into tomorrow with total rainfall amounts of between 25 and 40 mm (1 inch to 1.6 inches). The rain is expected taper off come Saturday evening.
Environment Canada meteorologist Mark Schuster says although heavy rain is likely, flooding concerns should be kept to a minimum.
"Well the good news with this weather system is it doesn't look like a lot of the rain is going to fall over a short period of time. It might fall heavily from time to time, but there could be some big breaks and there won't be any of those major downpours that you sometimes see with thunderstorms," says Schuster.
The rainfall is associated with a low pressure system crossing the lower Great Lakes.
Schuster says while flooding concerns aren't too serious, there are other potential problems.
"One of the concerns with rain at this time of year is a lot of the leaves are blocking a lot of the drains on the streets," says Schuster. "If you have one of these drains near your house it's probably a good idea to clear those up so that the water can run down, but for the most part this shouldn't have too much of an impact."
Schuster says southwestern Ontario is going to be spared freezing rain.
"It looks like temperatures are going to be quite warm rising up into the upper single digits tonight and then daytime high of about 12 C (54 F) on Saturday. Any risk of freezing rain is going to be more over eastern Ontario and more up into central Ontario."
The special weather statement covers both Windsor-Essex and Chatham-Kent.