The Essex Region Conservation Authority (ERCA) has issued a flood outlook.
Heavy rainfall is expected for Sunday evening which could produce heavy wind gusts and heavy rain.
The line of thunderstorms are approaching from Michigan and Lake Erie moving northeast.
Environment Canada is calling between 20 millimeters to 30 millimeters of rain.
The ERCA is warning the heavy rainfall could create ponding and areas of standing water.
"This rain could also cause smaller watercourses to rise, and some could spill their banks into adjacent low-lying areas," the notice said.
The statement will remain into effect until 12 p.m. Monday.
People are encouraged to take extra caution and avoid areas where flooding is occurring.
Residents are also reminded to stay away from rivers, streams, and shoreline areas during significant rainfall and wind events.
"The combination of slippery banks and fast moving water can be dangerous. Standing water can present its own unseen hazards. Children, pets and livestock should be kept away from flowing or standing water," the notice also said.