Southern Ontario: Thunderstorm Outlook for Monday, June 21, 2021

Forecast Discussion

There is the potential for some strong thunderstorm activity during the afternoon and evening on Monday as a cold front sweeps across the region. It’s currently uncertain exactly when this cold front will move through and storm development will be highly dependent on the timing of when this front moves through. Some models show it coming through earlier in the day which would mean storms would start to develop over Lake Ontario and Erie and track across upstate New York instead. The best chance at severe weather currently appears to be Eastern Ontario and around the Golden Horseshoe although this may shift. More details in future outlooks.