Figure 1 shows the surface observations at 7:00 pm CDT, which shows a strong low pressure over Saskatchewan with a stationary front extending east across northern Manitoba and a cold front extending south across southern Saskatchewan. A line of thunderstorms (squall line) is also observed across extreme southwestern Manitoba. This line of storms was responsible for this F1 tornado just north of Forrest in the evening hours of August 22nd.
According to Environment and Climate Change Canada (2018), an F1 tornado touched down at 8:15 pm CDT near Forrest, 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 Thu Aug 23 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/