Midwestern Ontario could see up to 40 millimetres of rain starting tonight in Grey, Bruce, Huron, Perth, and northern Wellington counties.
A special weather statement from Environment Canada is calling for rain to begin overnight on Tuesday and continue into Thursday morning.
Rainfall amounts of 20-40 millimetres are expected, but the ground has limited ability to absorb further rainfall.
This rainfall is associated with a Texas Low that will track across Southern Ontario Wednesday and Wednesday night.