Environment Canada has issued a special weather statement for Sarnia-Lambton.
The weather agency said there's the potential for a strong thunderstorm early Thursday morning.
Scattered strong thunderstorms over Michigan are expected to continue to track eastward and southeastward.
These thunderstorms may move over southern portions of southwestern Ontario near or shortly after sunrise.
There is considerable uncertainty as to the development, strength and track of these thunderstorms. Should these thunderstorms strengthen, there may be a threat for isolated wind gusts of 90 km/h and hail.