A tornado warning was lifted for all of Sarnia-Lambton shortly before 5 p.m. on Thursday, as the storm tracked east.
Environment Canada first issued a tornado warning for Sarnia, Petrolia, and eastern Lambton County just after 4 p.m. The warning was put into effect at 4:15 p.m. for the rest of Lambton County.
By mid-Thursday evening, most severe thunderstorm watches warnings were lifted.
The national weather agency warned that damaging winds, large hail, and locally intense rainfall were possible. They said this was a dangerous and potentially life-threatening situation, and residents were urged to take cover immediately.
Tornado warnings are issued when imminent or occurring thunderstorms are likely to produce or are producing tornadoes.
Bluewater Power reported multiple outages during Thursday's storm. More details are posted on the utility's outage map.
Emergency responders are also addressing downed trees and powerlines across Sarnia. Residents are being asked to be cautious when travelling on local roadways.