Heavy rainfall and thunderstorms are expected to last in Chatham-Kent for the entirety of the day.
Environment Canada issued a rainfall warning and a severe thunderstorm watch for the area early Tuesday morning.
The weather agency warned that heavy rainfall could see 40-50 mm accumulate, with some areas seeing amounts approaching 75 mm.
"Heavy downpours can cause flash floods and water pooling on roads," a release said, adding that localized flooding in low-lying areas is possible.
Alongside the rain, the area could see hail, wind gusts up to 100 km/h, and the chance of an isolated tornado.
Emergency Management Ontario recommends that you take cover immediately if threatening weather approaches.