A Special Weather Statement has been issued for Windsor-Essex with heavy rain on the way for the region.
Environment Canada issued the statement due to rainfall amounts of 30 mm to 50 mm, with isolated amounts of up to 100 mm possible over some parts of the area.
The national weather service says rain at times heavy is expected to move into southwestern Ontario early Wednesday evening and continue into Thursday morning.
Warning preparedness meteorologist Geoff Coulson says thunderstorms are likely as well.
"Those showers will be steady through the overnight hours, in fact, heavy at times likely," he says. "The worst of the showers and thunderstorms likely wrapping up around midday on Thursday but there could still be some lingering showers after that."
Coulson says they're tracking right now on radar a fairly extensive area of showers and embedded thunderstorms in the Chicago area and moving westward toward Iowa.
"hat whole complex of showers and thunderstorms is steadily moving east and we're expecting it to move into the Windsor area sometime this evening," he adds.
At this point, there is uncertainty regarding which areas will get the heaviest rain.
Rainfall warnings may be issued later Wednesday as necessary.
With files from Rob Hindi and Paul McDonald