Figure 1 shows the surface observations at 7:00 pm CDT, which shows a trough near the Manitoba/Saskatchewan border. This trough likely triggered thunderstorms on and near the MB/SK border, which ultimately led to this tornado.
According to Environment and Climate Change Canada (2018), an F0 tornado touched down at 10:30 pm CDT near Souris, 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 Sat Jul 26 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/