This tornado was observed by area residents who reported observing a ‘pencil-like twister’ touching down at 7:10 pm. It caused minor damage, snapping and uprooting trees.
Figure 1 depicts a warm front moving north into southern Ontario, bringing unusually warm weather across the region. At 2:00 pm, thunderstorms were ongoing on the warm front. This front and the orientation of the geostrophic vectors lead us to believe this was a north-northwest moving tornado.

According to Environment and Climate Change Canada (2018), an F0 tornado touched down at 7:10 pm EDT near Mount Pleasant, ON. The track and width of the tornado was not documented by ECCC. The tornado caused no injuries, fatalities or property damage.
Sources
NWS Weather Prediction Center Surface Analysis Archive. (2017). Surface analysis 18Z Sun Oct 15 1989. 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/