Touching down in a field and producing no notable damage, this F0 tornado passed near the town of Embro. It was observed by an Environment Canada employee who watched it churn harmlessly in the grass for several minutes.
Figure 1 depicts the surface observations at 8:00 pm EDT, which shows a stationary front across southwestern Ontario and an ongoing thunderstorm reported at London. This thunderstorm was responsible for this tornado.
Sources
NWS Weather Prediction Center Surface Analysis Archive. (2017). Surface analysis 00Z Mon Jul 23 2012. Retrieved from: https://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive.php
