A CANWARN storm spotter observed a tornado touching down briefly at around 8:00pm, snapping the branches off of trees. This was one of two tornadoes to touch down in Southern Ontario on June 2; the other was an F1 at Purple Valley that snapped trees and destroyed a pole barn.
Figure 1 depicts the surface observations at 8:00 pm, which depicts a low pressure in central Ontario with a cold front extending across southern Ontario. This cold front became the focus of intense thunderstorms, which eventually led to this F0 tornado.
According to Environment and Climate Change Canada (2018), an F1 tornado touched down at 12:00 pm EDT near Purple Valley, ON. The tornado travelled for 1 km and had a maximum width of 50 metres. The tornado caused no fatalities or injuries, but caused $60 thousand dollars in property damage.
Sources
NWS Weather Prediction Center Surface Analysis Archive. (2017). Surface analysis 00Z Thu Jun 3 1999. Retrieved from: https://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive.php
Environment and Climate Change Canada Data. (2018). Canadian National Tornado Database: Verified Events (1980-2009) – Public. Retrieved from: http://donnees.ec.gc.ca/data/weather/products/canadian-national-tornado-database-verified-events-1980-2009-public/