Flash flooding in Burlington, Ontario

Major flooding Monday afternoon in Burlington, Ontario. (Twitter photo #onstorm)

A series of late afternoon thunderstorms dumped two months worth of rain in several hours in Burlington, Ontario Monday afternoon. Over 125mm (5 inches) of rain was officially reported with some reports of as much as 200mm (8 inches) falling during the late afternoon drive. The storms were isolated in narrow bands along the western edge of Lake Ontario with no rain falling as little as 15 minutes away from the flooding. The result of the rain was severe flash flooding that closed numerous highways including the QEW across the western portion of the GTA. The water simply overwhelmed the small streams in the region as well as the sewers. While many cars were submerged and several drivers had to be rescued, no injuries were reported.

Thunderstorms also skirted eastern Ontario south towards upstate New York, again remaining southwest of greater Montreal. We enjoyed a mostly sunny, humid day with temperatures around 29C (85F). A cold front will approach the St. Lawrence Valley by the middle portion of the day today with an increased risk of showers and thunderstorms for Montreal. Severe weather is not expected at this time but heavy rain is always possible with any thunderstorm activity. Temperatures will reach 25C (77F) today. The showers will end this evening with skies clearing and lows around 15C (59F). On Wednesday look for a perfect day with sunny skies, dry and cooler with a high near 24C (75F).