Weekend storm brings heavy rain, but no tornadoes, to northwestern Ontario

A weekend storm brought heavy rain and localized flooding to northwestern Ontario.

However, despite warnings issued by Environment Canada prior to the storm moving through the region on Sunday, no tornadoes were confirmed.

"With respect to issuing tornado warnings, what we're looking for generally is rotation," Monica Vaswani, a meteorologist with Environment Canada, said Monday. "That's ... an inflow wind on one end, and an outflow wind on the other end."

"We're basically looking for these winds to ... be rotating," she said. "That indicates to us that the entire storm, what we call the mesocyclone, is essentially rotating and that could produce a tornado at the ground."

Vaswani said the weather radar did show that rotation on Sunday, leading Environment Canada to issue tornado warnings, alerts which were broadcast on television Sunday evening, for the Atikokan and Kakabeka Falls areas.

"Northwestern Ontario's climatology does allow for tornadoes throughout the summer months," she said. "It is a little bit late in the season to be seeing a tornado, so that might be what's a little bit more interesting about this, but I wouldn't call it rare."

However, while no tornadoes touched down, there was plenty of rainfall.