Figure 1 shows the surface observations at 1:00 pm CDT, which shows a strong low pressure in extreme southeastern Saskatchewan with a warm front extending east across southern Manitoba and a cold front extending south across North Dakota. The cold front triggered thunderstorms across southern Manitoba in the morning and afternoon hours of May 28th, which ultimately led to three tornadoes on this day.
According to Environment and Climate Change Canada (2018), an F0 tornado touched down at 2:00 pm CDT near Oak Lake, 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 18Z Thu May 28 1987. 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/