Figure 1 shows the surface observations at 7:00 pm CDT, which shows a strong low pressure over central Manitoba with a warm front extending east into northern Ontario and a cold front extending south across southern Manitoba. The cold front became the focus for supercells (possibly a squall line), which ultimately led to this tornado in southeastern Manitoba.
According to Environment and Climate Change Canada (2018), an F0 tornado touched down at 8:20 pm CDT near St. Malo, MB. The track and width of the tornado was not documented by ECCC. The tornado caused no fatalities, injuries or property damage.
NWS Weather Prediction Center Surface Analysis Archive. (2017). Surface analysis 00Z Thu Jul 24 1986. 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/