What to do if your favourite TV or radio show is interrupted by a tornado warning
Province’s alert-ready system has been in place since 2015
With summer tornado season in Ontario now underway, your favourite TV show or radio program might be interrupted by a loud siren or automated voice.
That alert is part of the province's Alert Ready system, which has been in place since 2015 — warning of potential tornados. So just how does that alert get triggered? Our CBC meteorologist Jay Scotland went right to the source to find out.
"We start the day before storms even start, to figure out what we can expect, what they're going to be and when," said Arnold Ashton, a severe weather meteorologist at the Ontario Storm Prediction Centre.
"Once they do form, we're all over the radar … and we're trying to determine where it's going, how severe it is and how it will impact various people."
Things get serious once meteorologists see rotation on radar, but they're still looking at all the circumstances around the "tornadic storm."
"Too many storms will steal the thunder, literally, of a tornadic storm. There's just not enough energy," said Ashton, a 32-year veteran of Environment Canada who is involved in forecasting for the entire province.
But if the conditions are right, "the tornado warning that we issue triggers the alerts that you hear and see on the radio or television," explains Ashton.
Social media provides 'flood of data'
Forecasters also rely on social media reports, what Ashton calls a "flood of data." They have individuals who sort through the information coming from storm spotters, Twitter and Facebook — which can result in a "steady stream when there's a lot of severe weather happening."
On television, your image will turn red and you'll start to see a crawl at the bottom of your screen, along with an automated voice saying there's a tornado warning in effect for your area.
On the radio, you'll hear a loud siren followed by an automated voice.
The warnings can come at any time and will abruptly interrupt whatever it is you're watching or listening to — so it's important to be prepared and know what to do.
Be prepared
"The primary thing is being aware of your surroundings," said Geoff Coulson, a warning-preparedness meteorologist with Environment Canada.
"When that screen goes red, or when that radio broadcast is interrupted, look around you … usually severe weather comes from the northwest, the west or the southwest sky, so look off in those directions for threatening skies."
Coulson suggests you should have apps on your smartphone or tablet for weather radar, or other weather information that could help identify a storm in your area.
He adds that the best shelter in case of a tornado warning is underground, in the "basement of a well-constructed building."
If there is no basement, he suggests you should:
- Get to the lowest floor.
- Shelter in the core of the building.
- Put as many walls as you can between you and the outside.
- Get as far away from windows and outer walls.
Watch vs. warning
Tornado watches tend to be issued far more often than tornado warnings.
A tornado watch can last a few hours because forecasters are watching the ingredients that could come together over the course of a day to form a funnel cloud or tornado, said Coulson.
A tornado warning is triggered when forecasters have seen something on radar, or received a report from a credible source saying there is a funnel cloud or tornado in the area.
"Lead time for [tornado warnings] may only be on the order of minutes because forecasters are treading that fine line between getting out a really necessary warning, or a situation where it's still borderline and a tornado may not form," he said. "They don't want to cry wolf."
Cell-phone based alerts
The future of the alert system may be changing, aligning Canada with alert systems in the U.S.
Coulson sees cell phone alerting — or cell tower based alerting — as the natural progression for broadcasting messages to people in areas that are threatened by severe weather.