After analyzing the latest data available, we have made the decision to issue an outlook upgrade. There will be a Very High risk for severe weather across the region today, with the focus on Extreme Southwestern Ontario. The severe threat will diminish slightly further east.
Environment Canada has stated that "this has the potential to be a highly significant severe weather situation" in Windsor-Essex, Chatham-Kent, Sarnia-Lambton, Elgin, and London-Middlesex.
The Very High risk area includes Windsor, Leamington, Chatham and Sarnia. In these areas, threats will include heavy rain, flooding, the risk for a few tornadoes, wind gusts of 120 km/h or greater, and hail 5-6 cm in diameter. These areas are expected to see the most severe thunderstorms during this event.
The High risk area includes London, St. Thomas, Goderich, Seaforth, Listowel and Stratford. In these areas, threats will include heavy rain, flooding, the risk for 1 or 2 tornadoes, wind gusts up to 115 km/h or greater, and hail 4-5 cm in diameter.
The Moderate risk area includes Simcoe, Brantford, Kitchener, Kincardine, Orangeville, Hanover, Collingwood, Owen Sound and Tobermory. In these areas, threats will include heavy rain, the risk for 1 or 2 tornadoes, wind gusts up to 110 km/h, and hail 3-4 cm in diameter.
The Elevated risk area includes St. Catharines, Hamilton, Oakville, Toronto, Newmarket, Peterborough, Barrie, Midland and Orillia. In these areas, threats will include heavy rain, wind gusts up to 100 km/h, hail 1-2 cm in diameter, and the risk for an isolated tornado.
The Low risk area includes Parry Sound, Huntsville, Bracebridge, Bancroft, Peterborough, Oshawa and Cobourg. In these areas, threats will include heavy rain, wind gusts up to 90 km/h, and the risk for an isolated tornado cannot be completely ruled out.
The Very Low risk area includes Barry's Bay, Belleville, Kingston, Brockville, Cornwall, Ottawa and Renfrew. In these areas, threats will include heavy rain and wind gusts up to 80 km/h.
A widespread Severe Thunderstorm Watch is in effect.
We encourage the public to monitor weather alerts and watch for updated forecasts as the day progresses. We will be posting all updates to our social media pages.