A series of dangerous thunderstorms in central Ontario left over a dozen communities under a tornado watch on Wednesday evening.

"We have a very large line of storms that are tracking their way across much of south and south-central Ontario. And we've got tornado warnings," the CBC's Claire Martin said shortly before 6:30 p.m. ET.

"They are now being issued all the way out towards southeastern Ontario, back down towards Lake Simcoe and at one point were in and around parts of southwestern Ontario."

Prior warnings had been issued for Fenelon Falls, Balsam Lake and northern Kawartha Lakes, Apsley, Woodview, and northern Peterborough County, Haliburton, Minden, southern Haliburton County, Orillia, Lagoon City and Washago areas, Orangeville, Grand Valley and southern Dufferin County, Lindsay and southern Kawartha Lakes, Belleville, Quinte West and eastern Northumberland County.

Most were downgraded to severe thunderstorm watches by later in the evening.

As of 11 p.m. severe thunderstorm warnings remained in effect for Stirling, Tweed, South Frontenac, Smiths Falls, Lanark, Sharbot Lake, Sarnia, Lambton, Cobourg , Colborne and Western Northumberland County.