Grimsby, ON F0 Tornado of September 3, 2011

City of Hamilton

Travelling for 2 km and with a width of 300 metres, this F0 tornado destroyed a gazebo and tore branches off of trees just to the west of Grimsby.

Figure 1. Surface analysis at 18Z on September 3, 2011 showing geopotential height contours, surface observations, fronts and pressure centres (WPC, 2017)

Figure 1 depicts the surface observations at 2:00 pm EDT, which shows a cold front moving across Hamilton. This front triggered thunderstorms across southwestern Ontario, which ultimately led to this tornado.


NWS Weather Prediction Center Surface Analysis Archive. (2017). Surface analysis 18Z Sat Sep 3 2011. Retrieved from: