We are currently watching the risk of a few isolated severe thunderstorms across portions of Southwestern Ontario this afternoon and evening.
Across the Extreme South along the shores of Lake Erie into the Niagara region, showers and thunderstorms are likely to develop and move northeast. Some of these thunderstorms may produce heavy rain over 50mm in a short period of time, 70-90km/h and 1-1.5cm hail. An isolated pocket of 2cm hail may develop in the strongest storms today but that seems unlikely. This risk also extends along the shores of Lake Huron where the environment could set up to support some isolated severe thunderstorms. This risk extends from Owen Sound and the Bruce Peninsula through to Kincardine and Goderich, and also extends inland towards Stratford. The same risks of 70-90km/h wind gusts, ~1cm hail, and 50mm of rain are possible. Overall, the risk is generally low as the storm development is questionable. This area is highlighted in green or marked with a '2.'
Elsewhere, non-severe thunderstorms are expected in the blue regions marked with a '1'. The non-severe thunderstorms include the risk for heavy rain between 20 and 40mm, with locally higher amounts and moderate wind gusts below 80km/h with small hail. Areas in the 'area of interest' or the area highlighted in a black dotted line can expect the best risk of these non-severe, isolated flash flooding storms. Some of these storms may briefly become severe due to the rainfall totals from these storms. Further east, these threats will be lower.