LONDON, Ont. - Tom Kroesbergen had to cut a cottage trip short and return home to his farm Thursday morning after a sinking call from an employee.

His farm, south of Ailsa Craig, Ont., looked like a tornado had criss-crossed through his corn fields before lifting his entire storage barn, snapping it, and scattering the debris over power lines and a neighbour's field.

Kroesbergen's property sustained $500,000 worth of structural damage alone.

While Environment Canada has yet to confirm a tornado hit the area, they did report that one touched down between Cambridge, Ont., and Burlington, Ont., with a damage track about 15 km long and as much as 300 metres wide.

They categorized it as an F1, which packs winds of between 120 and 170 km/h.

There were dozens of significant storm cells across Southern Ontario on Wednesday - as far west as Windsor, Ont., through London, up to Lake Ontario, Geoff Coulson of Environment Canada said.

In the wake of the deadly tornado that hammered Goderich, Ont., on Sunday, residents like Kroesbergen, in neighbouring Middlesex County, are reeling from severe weather that sliced through power lines and ripped swaths through fields Wednesday night.

Environment Canada is following up on reports of damage through the northwestern part of Middlesex County.

"It was definitely a tornado. Nothing else can do that," said Chris Archambault, pointing to the torn roof of his house near Ailsa Craig, the roots of a 15-metre-high tree, the trunk nowhere to be found, and his untouched, spotless car.

Jack Murray, 68, who works at Shady Pines Campgrounds just on the outskirts of Nairn, Ont., north of London, said, "There was an awful swirling in the skies, then a sound like an old freight train. It lasted all of about 20 seconds.

"One second all the trees are upright, the next second they've fallen to the ground."

"I've never been so scared in my life," said Marilyn McLeod, a London resident who frequents the park. "For a couple minutes there, I was definitely thinking - it's Goderich."

Kelly Jones, who works at a diner in Nairn, snapped photos of a funnel cloud around 8:30 p.m. Wednesday.

"The sky was a bright purple, absolutely beautiful. There were three funnel clouds coming from three different directions."

There were no reports of injuries in the London region.

While the Goderich twister hit the coast directly on the heels of an official warning on Sunday, Environment Canada was much quicker to issue alerts Wednesday, posting a tornado watch at 11 a.m. and upgrading that to a warning just after 6:30 p.m.

The tornado watch was issued for Goderich around 2 p.m. on Sunday, changing to a more sinister warning at closer to 4 p.m.

"We've been using the last few days to educate the public on the differences between watches and warnings. A watch is a heads-up and a segue into a warning is a tap on the shoulder - the lead time can be short," Coulson said.

Environment Canada sent a damage survey team between Cambridge, Ont., and Burlington, Ont., which suffered significant tree damage, but has yet to dispatch a team to Middlesex County.

"We're still in the process of determining where the damage occurred," Coulson said, adding that a team would be sent to the London area to assess the storm aftermath and determine - officially - whether tornadoes ripped through the farms.