The Ausable Bayfield Conservation Authority (ABCA) says minor flooding is possible in low lying flood plain areas this weekend.
At least 75mm of rain is in the forecast for Sunday and Monday, and the ABCA said slippery and unstable riverbanks, and cold and fast-flowing water will combine to create hazardous conditions.
The Authority expects the rain to come in two waves, with the first reaching the ABCA watershed early Sunday afternoon, and capable of producing upwards of 40mm of rainfall through Monday morning.
It said the exact track and timing of the second wave of rain is less certain. Rainfall is forecast to begin mid-day on Monday, and could result in an additional 30mm before clearing out on Tuesday morning.
Residents are reminded to use caution near all watercourses.
Significant flooding is not expected at this time, and flows on the area's larger rivers are not likely to peak until Tuesday. They will likely remain higher than normal for the rest of the week.
The ABCA said the bulletin will remain in effect until 9:00 a.m. on Wednesday, May 20, 2020, unless local conditions warrant further updates.