The Ausable Bayfield Conservation Authority (ABCA) is warning that strong winds and waves could cause flooding and erosion along the Lake Huron shoreline.
In a statement, the authority said a cold front associated with an intense low-pressure system will move across the watershed Wednesday.
Strong northwest winds developing Wednesday are expected to peak Thursday morning with maximum sustained speeds of 40-50 kilometres per hour and gusts up to 80 kilometres per hour.
The ABCA said the wind, combined with near record-high water levels on the lake, will result in "higher than normal waves hitting shoreline areas."
There could be minor flooding of low-lying areas and an increased risk of erosion to lakeshore bluffs.
Residents and municipal officials are reminded to stay well back from breaking waves and to approach top-of-bluff areas with caution in case there has been any movement of the lake bank.
Winds are expected to diminish through the day Thursday but remain steady out of the northwest through Friday morning.