This weekend marks the 30th anniversary of when an F-4 tornado ripped through the Barrie area and many wonder if it could happen again.

Geoff Coulson has been a meteorologist at Environment Canada for 32 years and it was early in his career when he witnessed events unfold that would lead to an unprecedented outbreak of severe thunderstorms, storms that’s spawned 14 tornadoes in six hours.

It was May 31, 1985 when one tornado ripped through Grand Valley before causing major damage in Tottenham. While another tornado touched down in Barrie’s south end, twelve people died that day.

Coulson says severe thunderstorm watches and warnings had been issued.  

“It was recognized even back in 1985 that this was going to be a big day for thunderstorms. Thunderstorms need that heat and humidity to be the fuel that drives them, we knew we had a lot of that, we knew it was unstable meaning that once these storms started to form they would get pretty significant quickly and the last ingredient was a cold front sweeping in from west to east,” says Coulson.

At the time Doppler radar had just been introduced and captured an image of the storm over as the tornado hit Barrie, basically showing the areas of intense rainfall.

Today forecasters can see much more detail in images of the storm that hit Goderich.  Dave Sills is a severe weather scientist for Environment Canada and says Doppler can now show the direction that water droplets are moving which can help detect rotation.

“We can't really see the tornado because it's too small but. We can see that larger circulation that a tornado is possible,” says Sills.

While research is revealing the anatomy of storms that have produced tornadoes, it's still difficult to predict exactly where and when a tornado will form. Historically tornadoes tend to occur on a line between Windsor/London and Barrie.

Coulson urges the public to pay closer attention to severe thunderstorm watches and warnings. He says it’s important not to forget what happened thirty years ago because it could happen again.

“I look at audiences that I am speaking to and they are 20 or something they weren't around or were very young when this outbreak occurred back on May 31, 1985 and don't realize that something of this intensity this violence can happen here in southern Ontario,” says Coulson

Tornado season in central Ontario starts April and continues through October and on average about ten tornados touch down each year.