Figure 1 depicts the surface observations at 4:00 pm CDT, which shows a low pressure system on the Saskatchewan/Manitoba border with a stationary front extending east across Manitoba and a trough of low pressure extending southwest across Saskatchewan and Montana.

According to Environment and Climate Change Canada (2018), an F0 tornado touched down at 4:25 pm CDT near Dufresne, MB. The path 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 Sat Jul 20 2002. 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/