Residents living on Lake Erie or Rondeau Bay should take precaution, as a flood outlook has been issued by the Lower Thames Valley Conservation Authority.
Large amounts of rain and possible freezing rain may create a storm surge Friday into Saturday along with wave spray flooding, shoreline damage and erosion.
Rain could be heavy at times. Ten to 50 mm could be dumped on the area by the time it stops.
Waves on the lake are predicted to be 1.5 to 2 m in height.
There is the possibility of low-level flooding around east-facing Lake Erie and Rondeau Bay communities such as Shrewsbury, parts of Erieau, and Wheatley.
Residents and animals should stay away from all bodies of water.
The watch will remain in effect until Saturday.