Figure 1 depicts the surface observations at 1:00 pm CDT, which shows a trough of low pressure moving eastward across southern Manitoba. This trough was the focus for intense thunderstorms in the afternoon hours of August 17, which ultimately led to two tornadoes across southern Manitoba.

According to Environment and Climate Change Canada (2018), an F1 tornado touched down at 3:55 pm CDT near Domain, 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 18Z Tue Aug 17 1999. 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/