Brinsley, ON F1 Tornado of July 13, 2004

London - Middlesex

On a path 6 kilometres in length and 10 metres wide, the tornado caused mostly minor damage to trees and crops. At one farm, a barn roof was removed and a drive shed severely damaged. Their debris was thrown around the property, piercing the ground and other buildings.

This was the strongest of three tornadoes that touched down in Essex County on July 13; the other tornadoes were an F0 at Elimville and an F0 at Farquhar.

Figure 1 depicts the surface observations at 2:00 pm EDT, which shows a stationary front in southwestern Ontario. This front was the focus for intense thunderstorms in the late-afternoon hours of July 13th, which ultimately led to this F1 tornado.

Figure 1. Surface analysis at 18Z on July 13, 2004 showing mean sea-level pressure (MSLP) contours, surface observations, fronts and pressure centres (WPC, 2017)

According to Environment and Climate Change Canada (2018), an F1 tornado touched down at 6:10 pm near Brinsley, ON. The tornado travelled for 6 km and had a maximum width of 10 metres. The tornado caused no fatalities or injuries, but caused $30 thousand dollars in property damage.


NWS Weather Prediction Center Surface Analysis Archive. (2017). Surface analysis 18Z Tue Jul 13 2004. Retrieved from:

Environment and Climate Change Canada Data. (2018). Canadian National Tornado Database: Verified Events (1980-2009) – Public. Retrieved from: