Friday storm a 'weather war,' climatologist says

Friday's wild summer storm across Ontario, the most active weather event of the season, is described as an all-out weather war by Canada's environment guru.

Cold and hot air masses battled over Southern Ontario, causing severe thunderstorms

Trees and power lines were the big casualties in Friday's powerful storms. (Julia Chapman/CBC)

Friday's wild summer storm that hit Hamilton and scores of other Ontario communities was an all-out weather war, says Canada's environment guru.

A cold front from Canada and a hot, humid air mass from the United States "battled over" Southern Ontario, creating severe thunderstorm activities across the province, explained David Phillips, senior climatologist with Environment Canada.

"Weather wars between the warm and the humid, the cool and the dry will often set off thunderstorms and no surprise they did," he said, calling it the most active weather event of the year.

From Windsor to Ottawa and Lake Erie to North Bay, a large area of the province was affected by heavy rain, strong winds, hail and microbursts.

"This storm had everything that you'd expect from a nasty summer storm," Phillips told CBC Hamilton.

The wild storm started Friday morning and lasted about 18 hours, according to Phillips. It kicked off in Callander near North Bay with severe wind, causing the town to declare a state of emergency, before moving eastward and southward.

The first significant damage in Hamilton took place at 6:30 p.m. Friday night, when trees fell down, with at least two more large storms moving through around 8:00 pm and 9:30 p.m. Throughout the night, wind gusts up to 106 km/h were recorded at Hamilton International Airport. Royal Botanical Gardens saw 45 millilitres of rain.

Compared to other parts of the province, however, Hamilton had it easy, Phillips said. St. Catharines, for example, saw 85 millilitres of rain.

"That's more than a month worth of rain in just a couple of hours," he said.

Dramatic temperature drop

The most prominent sign of the weather war between cold, heavy air and warm, light air, according to Phillips, was the dramatic temperature drop. Friday was the warmest day in the summer at 34 C, but temperature dipped to 22 C during the storm, a 12-degree drop in an hour.

Although the exact time and location of the storm could not be predicted, Environment Canada issued active weather warnings days before the storm. A Tornado watch was issued for Hamilton just before 6:00 p.m.and lasted until after 8:00 p.m.

"People were well-armed with the notion that the weather was going to take a dramatic turn on Friday and everybody was looking forward to the cooler, dryer air," he said. "But we warned that that would not come without a price."

Although Friday's wild events will not be the last storm this summer, Phillips said the storm spelled an end to the heat wave that broiled Hamilton for the past week. Residents can expect much more comfortable days this week with mild temperature as they continue to clean up after the storm.