Severe thunderstorms move across region, causing tornado warnings

An intense thunderstorm that moved across the national capital region Monday afternoon brought strong rain, reports of hail and localized flooding, and warnings of possible tornadoes.

Environment Canada issued a tornado warning for Gatineau shortly after 4 p.m., saying a severe thunderstorm capable of producing a tornado was located near Buckingham, moving north at 30 km/h. An emergency alert went to phones in Ottawa as well, but no formal tornado warning was issued for the city. By 4:30 p.m., the tornado warning was no longer in effect in Gatineau. 

Environment Canada meteorologist Peter Kimbell tells CTV News Ottawa the warning in Gatineau was issued based on radar observations.

"It was brief. There was a radar signal that led to the warning but nothing is confirmed," he said. "The system is now well into Quebec."

Tornado warnings were in effect for The Papineauville and Chénéville area.

Just after 4:30 p.m., a tornado warning was in effect for the Bonnechere Valley area in eastern Ontario, but that has also since ended. 

The weather agency had issued a severe thunderstorm watch for the Ottawa Monday, and it was later upgraded to a severe thunderstorm warning as heavy rain and loud thunder battered downtown. The thunder briefly interrupted police chief Eric Stubbs while he was answering questions in a media availability ahead of Monday's police services board meeting. The thunderstorm warning ended just before 5:15 p.m., but a second warning for a different line of storms was issued at around 6:20 p.m.

"Environment Canada meteorologists are tracking a severe thunderstorm capable of producing strong wind gusts, up to toonie size hail and heavy rain," the warning said.

The warning ended by 6:30 p.m.

Kimbell said he expected more rain over the coming hours as another line of storms stretching up from the Belleville area moves over Ottawa.

Some residents in Ottawa reported seeing hail in parts of the city, while others said streets were flooded as the storm moved over the city Monday afternoon.

Hydro Ottawa attributed a power outage affecting more than 2,000 residents in Alta Vista to a lightning strike. The utility estimated power could have been restored by 6 p.m. but it was pushed back to 10 p.m.

According to Environment Canada's weather radar, a very powerful band of showers developed south of the city around 2 p.m. and began moving north toward Quebec.

"Heavy downpours are likely to cause flash floods and water pooling on roads. Large hail can damage property and cause injury," the warning says. "Strong wind gusts can toss loose objects, damage weak buildings, break branches off trees and overturn large vehicles."

This comes as Ottawa also deals with poor air quality due to wildfire smoke from Quebec. The Air Quality Health Index was at a 10 at 7 a.m. Monday, dropping to 6, or a "moderate risk" by 3 p.m. The air is expected to clear Monday night into Tuesday. A smog warning remain in effect for Gatineau.

Flooding in Ottawa at the corner of Third Avenue and O'Connor Street in Ottawa after an intense thunderstorm. June 26, 2023 (Courtesy: Greg MacEachern)

OTTAWA FORECAST

A severe thunderstorm watch is in effect. 

The rain will end around midnight. Ottawa could see between 25 and 40 millimetres of rain by the time the showers taper off. The overnight low will be 18 C.

On Tuesday – a mix of sun and cloud with a 40 per cent chance of showers. There will be a risk of a thunderstorm in the afternoon.

Temperatures will climb to 23 C on Tuesday, and the humidex will make it feel more like 31. The AQHI should hover around 3 Tuesday.

It will be cloudy with a 60 per cent chance of showers Tuesday evening. Temperatures will fall to 16 C overnight.  

Wednesday’s outlook is a mix of sun and cloud with a 60 per cent chance of showers and a high of 27 C.