Figure 1 shows the surface observations at 4:00 pm CDT, which shows a small low pressure in the extreme corner of southeastern Manitoba. Storms were likely the result of lake-breeze interactions across southern Manitoba.

According to Environment and Climate Change Canada (2018), an F0 tornado touched down at 4:40 pm CDT northwest of Poplar Point, MB. The track and width of the tornado was not documented by ECCC. The tornado caused no fatalities, injuries or property damage.
Sources
NWS Weather Prediction Center Surface Analysis Archive. (2017). Surface analysis 21Z Tue Jul 8 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/