Environment Canada says conditions are favourable for funnel clouds in the Greater Toronto Area and most of Southern Ontario on Thursday evening.

The weather agency says some unseasonably cold and unstable air around Southern Ontario could cause rotation to develop.

"Heavier showers or weak thunderstorms could briefly produce funnel clouds, and some of those funnel clouds may briefly become tornados," Geoff Coulson, a Warning Preparedness Meteorologist with Environment Canada told CBC News.

These types of tornadoes tend to be short-lived, but Coulson says people should be prepared to get into shelter on the off-chance a tornado develops.

"Some funnel clouds just remain funnel clouds and there is no contact with the surface, but what's important to note is the funnel does not need to be visible all the way to the ground for it to be a tornado," says Coulson.

"If people are seeing a funnel next thing they should be doing is look under the base of the funnel and if they are seeing dust and debris swirling around and being picked up, it is in fact a tornado."

Coulson says storms Thursday afternoon will likely bring dime-sized hail, wind gusts up to 70 kilometres an hour and frequent lightning.

Environment Canada says to treat any sighting of funnel clouds seriously, and if you spot one take shelter immediately.

Meteorologists say these types of tornados usually appear with little to no warning.