The London region will see significant rainfall overnight following an afternoon of thunderstorms as a hot and humid air mass covers the area.
At around 7:55 p.m. Wednesday, Environment Canada issued a rainfall warning for London-Middlesex as showers and thunderstorms are expected to continue throughout the evening.
"Rainfall amounts of 20 to 40 millimetres have fallen today over some areas. Additional showers and thunderstorms have the potential to result in total rainfall amounts near 50 mm by midnight," a statement from the weather agency read.
Localized flooding in low-lying areas is possible. Residents are advised to watch for possible washouts near rivers, creeks and culverts.
The rain is supposed to taper to scattered light showers overnight.
Just before 5:30 p.m. Wednesday, Environment Canada upgraded a severe thunderstorm watch to a warning for London-Middlesex. The warning was lifted at around 6:23 p.m. and a watch remains in place.
The weather agency issued a severe thunderstorm watch for London, Middlesex County, and Oxford County on Wednesday morning, saying storms could develop throughout the afternoon. The weather agency says the heat and humidity are creating conditions that are favourable for the development of severe storms.
"Some of these thunderstorms may become severe with strong winds, large hail and heavy rain. Tornadoes also can not be ruled out," Environment Canada said.
It's expected the threat of storms will come to an end Wednesday evening.