TORONTO — Environment Canada says it sends alerts to cellphones as soon as a tornado warning is issued, but the fast pace and unpredictable nature of twisters mean some residents may not receive the emergency message before one hits.
The weather office has faced criticism for the timing of its alert regarding Thursday's tornado in Barrie, Ont., which ravaged a neighbourhood in the city's south end and sent multiple people to hospital.
Some have reported receiving the alert only moments before it touched down -- or even after.
"We didn't get the tornado warning until 20 minutes after everything ... we had no idea there was a tornado," said Jacob Musgrove, who was home with his brother when the tornado struck. Their shed and gazebo were destroyed but the inside of their home was less seriously damaged, they said.
Steven Flisfeder, a warning preparedness meteorologist with Environment Canada, said the cellphone alerts are automatically pushed out as soon as the agency issues a tornado warning for an area, though there may be a few seconds' delay between the two.
The weather office put out a severe thunderstorm watch for the Barrie area just before noon Thursday, and upgraded that to a severe thunderstorm warning at 2:28 p.m., neither of which would have triggered an alert, he said.
A tornado warning was issued at 2:38 p.m., which would have sent an alert to phones as well as TV and radio stations, he said.
Environment Canada has not yet pinned down the exact timing of the tornado, but estimates it touched down between 2:35 p.m. and 2:40 p.m., Flisfeder said.
"So some people did have a bit of a lead time, a few minutes, depending where they were within that region, but unfortunately, it appears that there could have been a delay for other people where the tornado had already touched down and the tornado warning hadn't been issued quite yet," he said.
Those "further along the track" of the tornado's path would have had more notice than those close to its starting point, he said.
The agency strives to give people 10 to 15 minutes of lead time, "but we just try to get the warning out as soon as we can and hopefully people have time to seek shelter and get themselves to safety," he said.
There isn't a specific set of criteria to decide when a tornado warning is issued, since different things could be a "clear sign" of a twister, he said.
Environment Canada monitors radar imagery and looks for signs of rotation within a storm, and any indication from people on the ground that a tornado has touched down, he said.
"With tornado warnings, it's one of the most elevated warnings we can send ... so we don't like to overly alert because of potential warning fatigue and people thinking we're crying wolf if we send too many warnings," he said.
"So it's a delicate balance, where we want to be sure that there is a really good cause for the tornado warning to be issued."
Barrie Mayor Jeff Lehman said Thursday that while there wasn't much time between the alert and the tornado, the warning system in place today is much better than it was when the city was hit by a deadly twister in 1985.
"We look at today, there was at least the warning of severe weather in the afternoon. We know that there were watches and so on that were publicized and everybody's got weather apps and information on their phones and watch on TV and it runs on the ticker on the bottom," he said.
"And I hope that a number of people saw the information that was there and that that probably saved some lives."
- with files from Nicole Thompson in Barrie, Ont.
This report by The Canadian Press was first published July 16, 2021.
Paola Loriggio, The Canadian Press