Figure 1 shows the surface observations at 1:00 am CDT, which shows an ongoing thunderstorm near Roblin (marked by an ‘R’). This thunderstorm was responsible for this brief F0 tornado.

According to Environment and Climate Change Canada (2018), an F0 tornado touched down at 11:00 pm CDT near Roblin, 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 06Z Fri Jul 27 1990. 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/