Hamilton, Burlington, Brantford under severe thunderstorm watch, with tornado risk

Hamilton, Burlington, Brantford under severe thunderstorm watch, with tornado risk

Environment Canada warns of hail, 110 km/h wind gusts

Conditions across southern Ontario are ripe for the development of dangerous thunderstorms Wednesday afternoon and evening, Environment Canada says, with some areas also with the risk of a tornado.

Around noon, the federal agency placed virtually all of southwestern Ontario — including Hamilton, Burlington, Brantford and Niagara — under a severe thunderstorm watch.

Much of eastern Ontario is also affected, but conditions could be most severe in the area between London and Belleville, stretching as far north as Port Elgin and Lake Simcoe.

At 5:43 p.m., the weather agency also added a tornado watch for Hamilton, Burlington and Brantford.

Environment Canada warns of destructive winds

Wind gusts could reach 110 km/h, there could be as much as 50 millimetres of rain, and hail the size of ping pong balls could develop, Environment Canada said.

"Significant damage or destruction to infrastructure, homes and the natural environment is possible," the service said.

"In the event of a tornado, or if a tornado warning is issued for your area: go indoors to a room on the lowest floor, away from outside walls and windows, such as a basement, bathroom, stairwell or interior closet. Leave mobile homes, vehicles, tents, trailers and other temporary or free-standing shelter, and move to a strong building if you can. As a last resort, lie in a low spot and protect your head from flying debris... If you hear a roaring sound or see a funnel cloud, swirling debris near the ground, flying debris, or any threatening weather approaching, take cover immediately."

It added that utility outages are possible as is damage to property and trees.

Conservation Halton issued a statement noting that while it does not anticipate widespread flooding, children and adults should stay away from watercourses like bridges and streams where fast-flowing water could be dangerous.

Keep catch basins, eavestroughs and downspouts clear

The City of Hamilton says it has dispatched crews to clear catch basins, culverts and ditches, as part of its response to the thunder and rain forecast.

It is also inspecting other areas at risk of flooding, and has staff on standby to help with traffic control on roads that may experience ponding.

The city advises residents to clear their catch basins, eavestroughs, downspouts and backwater valves.

Residents might also want to have their sump pump handy and working properly, the city suggested, and to move "any valuables from basement floors to higher ground."

Justin Chandler is a CBC News reporter in Hamilton. He covers stories of all kinds from places including picket lines, court rooms, council meetings and research labs. Justin has a special interest in how public policy affects people, and loves a quirky human-interest story. Before CBC Hamilton, he worked for TVO and on a variety of CBC teams and programs. He co-hosted Radio Free Krypton on Met Radio.