Environment Canada confirmed that an F1 tornado occurred Wednesday evening between Cambridge and Burlington.

The tornado's 15-kilometre track began near Little's Corners and ended near Westover. The greatest damage occurred in Kirkwall.

The damage rating was based on tree damage noted along the storm's path.

Environment Canada is also investigating reports of funnel clouds in Lucknow, Grand Bend, Parkhill, Petrolia, Guelph, Middlesex County and Kingsville.

The sightings were reported during a nasty storm that put several communities under tornado warnings or watches, brought a barrage of lightning strikes, heavy rain, strong winds and hail, and plunged thousands of homes and businesses into darkness.

About 3,000 Hydro One customers were without power as of 7 p.m. Thursday evening. This morning, 16,000 customers were without power.

All weather warnings or watches have been lifted. There have been no reports of serious injuries.

At the storm's peak, Toronto was under a tornado watch and severe thunderstorm warning, as repeated lightning strikes created a spectacular light show in the sky.

People checking for damage

There have been a few reports of damage in Toronto.

It's believed lightning struck a home near Sheppard Avenue East and Meadowvale Road, sparking a fire that spread to a neighbouring home and caused about $100,000 in damage.

The nasty weather also interrupted several big events.

The CNE was forced to shut down its midway and close its gates early, while Toronto FC's outdoor match against FC Dallas at BMO Field was called halfway through the game. The match was replayed Thursday morning.

At one point, tornado warnings were in effect in several areas, including Hamilton, Oakville, Mississauga and Brampton.