Those under 30 years old may have no idea that fatal tornadoes were not uncommon in Ontario before they were born. 

An F4 tornado is well overdue, says Geoff Coulson, Environment Canada's warning preparedness meteorologist.

"The big one" is actually about 15 years overdue, he says.

'We feel that we are, in fact, overdue for a tornado of that intensity in Ontario.' - Geoff Coulson, Environment Canada meteorologist

"On May 31, 1985, there were 13 tornadoes across southwest and south-central Ontario, two of those events were rated as F4 events," said Coulson, who led a weather preparedness seminar for Hamilton emergency services, city workers and school board delegates.

In 1985, a series of tornadoes ripped through Central Ontario, but it was a pair of F4s, Coulson said, that killed eight in Barrie, and three in Grand Valley, a community west of Orangeville.

"We have not seen the like in terms of an event that intense since that time, and we feel that we are, in fact, overdue for a tornado of that intensity in Ontario."

Ontario residents are also due for more flash flooding, more lightning, and yes, more snow as a result of climate change.

"As we get further into the month of May, more episodes of heat and humidity, those are the ingredients a thunderstorm needs to form," Coulson said, calling it an "opportunity" for families to have the "preparedness" conversation.

That conversation includes what does your house need to survive for 72 hours without help, from diapers to dog food, and batteries to a printed contact list from a soon-to-be drained cellphone.

There were plenty of tips to be pulled from the two-hour workshop aimed at informing those that make the call to close a road or cancel a playoff soccer game.

"We're using this group as a way to spread the word from here," Coulson said. "We're having key decision-makers in the crowd… and they'll pass the word along."

Of the tips, many were common sense. Here are a few:

On lightning

  • Find shelter inside. If none can be found, use a vehicle, but only if it has a metal roof. If you're camping, go to a low-lying area and crouch as a last resort.
  • Do not resume a child's sports game, or any sport for that matter, until 30 minutes after the last thunder is heard.

On extreme winds

  • The underpass is not a safe place to stop when driving on the highway in high winds. Coulson said it funnels wind — and flying debris — leaving your stopped car in the most susceptible position. Keep moving, and get off the highway to get away from the storm.
  • Every year there are 50 to 60 "downburst" wind events in the province, and roughly 12 tornados.
  • EF-4 tornadoes (as they are now called, opposed to F4) happen once every 15 years.
  • The last EF-4 in Ontario was nearly 30 years ago in 1985. It killed 11 people.
  • For schools, heavy winds can take out large flat-roofed areas quickly, as can be seen in this video of a school gymnasium below. If you can't get to lower floors, go to the centre of a building structure. "The more walls the better," Coulson said.

On the 'smartphone force field'

  • Most weather events require you to get low, close to the core of buildings and generally, away from windows. Coulson said people who want that viral video get close to windows to record footage, exactly the place where debris from a storm will cause the most damage. The message? Stay inside and stay away from windows.
  • Coulson said it goes without saying that you should be inside if you can when big weather hits. He showed this video to the crowd of roughly 50 people. It makes clear how some people ignore that common sense rule.

On climate change

  • Climate change will bring about more "Burlington type" overland flooding. In last year's flood in that city, nearly two months of rain — 190 mm — fell in an afternoon causing flooding. Most of the damage was uninsurable as overland flooding is not covered by Canadian insurance companies.
  • To be prepared, Coulson suggested residents audit what they have in the basement now for family keepsakes, important documents, photos and electronics and move them to higher floors.