Athens, ON F1 Tornado of July 17, 2012

Brockville - Leeds and Grenville

This low-end F1 tornado had a path that was 3 km long and 300 metres wide. It first struck rural properties, where trees were uprooted and heavy farm equipment was thrown up to 15 metres, then struck the town of Athens. It caused considerable damage in town, with trees snapped, uprooted and tossed onto homes and vehicles. At one property a shed was destroyed, and a nearby house had a cinderblock chimney knocked down. Witnesses in town reported seeing a funnel cloud touching down as the damage occurred.

This was one of two tornadoes to touch down on July 17, 2012. The other occurred at Summerstown (F0).

Figure 1. Surface analysis at 21Z on July 17, 2012 showing mean sea-level pressure (MSLP) contours, surface observations, fronts and pressure centres (WPC, 2017)

Figure 1 depicts the surface observations at 5:00 pm EDT, which shows a cold front moving from northern Ontario through southern Ontario. This front became the primary mechanism for initiating severe thunderstorms throughout the afternoon hours of July 17th, which ultimately led to two tornadoes across southern Ontario.


NWS Weather Prediction Center Surface Analysis Archive. (2017)Surface analysis 21Z Tue Jul 17 2012. Retrieved from: