Environment Canada has cancelled tornado and thunderstorm warnings for Southern Ontario.

A tornado warning for Smiths Falls, Perth, Eastern Lanark County and Plevna, Sharbot Lake, and Western Lanark County have ended as of 6:20 p.m., Monday, May 18th, 2015.

According to Environment Canada, the severe thunderstorms have "weakened or moved out of the region."

Severe thunderstorm warnings have been cancelled for Ottawa South, Richmond and Metcalfe, Ottawa North, Kanata, Orleans, Renfrew, Perth, and Gatineau.

Thunderstorms are still moving through the region, but Environment Canada has downgraded the system. Thunderstorm watches are still in effect for some regions.

Stay tuned to CTV Ottawa for more on this storm system.