Environment Canada issued a severe thunderstorm warning for Windsor, Essex, Leamington, Chatham and Rondeau Park.
The agency says it's tracking a severe thunderstorm capable of producing strong wind gusts and torrential rain.
"Torrential downpours and frequent lightning are associated with this storm," Environment Canada said in a release.
Local rainfall could amount to 50 mm within an hour and 75 mm overall Wednesday morning.
"There is also a lesser threat of wind gusts to 90 km/h," the agency said in a release. "Strong wind gusts can toss loose objects, damage weak buildings, break branches off trees and overturn large vehicles.
"Remember, severe thunderstorms can produce tornadoes."
Emergency Management Ontario recommends that you take cover immediately, if threatening weather approaches.