Environment Canada has issued an special weather statement citing the potential for heavy rainfall throughout the region on Saturday.
Current radar images show heavy rain showers and isolated thunderstorms over Lake Huron and heading northeast.
Much of southern and Midwestern Ontario could see upwards of 20-30 mm in most areas and even upwards of 40-50 mm in some areas.
People are urged to use caution while driving as heavy rain could cause pooling in some areas as well as around creeks and rivers.
