Ontario: June winds with a November punch

Heavy rain and thunderstorms could swiftly cause hazardous conditions throughout the region

As the storm moves into southern Ontario, it will draw into a rush of atmospheric moisture, resulting in heavy rainfall and embedded thunderstorms. The rainfall is expected to further intensify Wednesday overnight as a cold front approaches. The most powerful storms could dump 50- 60+ mm of rain in some areas, raising fears about flooding in low-lying and poorly draining areas.

In addition to torrential rains, it's likely we'll see storms reach severe parameters as wind shear and spiraling updraft potentials become high to extreme. As such, forecasters cannot rule out the risk of an isolated tornado from the storms moving in from Michigan. As the low swiftly strengthens, a strong, low-level jet stream is forecast to rush throughout the region, causing unusually violent gusts for this time of year.

Wind gusts of 80 to more than 90 km/h are predicted Wednesday night and early Thursday morning, before progressively decreasing later in the day. Conditions are predicted to continue blustery, with sustained west winds behind the leaving system. The highest gusts are expected along Lake Erie's shoreline and over the Niagara Peninsula, where some spots may temporarily approach 100 km/h, particularly in and around thunderstorms before sunrise Thursday .For southern Ontario, it's a reminder that summer storms can be just as powerful as those associated with colder months and that this one may strike with little warning.

Environment Canada

Warning: Lake Erie waves may exceed 10m.