Figure 1 depicts the surface observations at 7:00 am EST, which shows a low pressure across Montana with a stationary front across Southern Saskatchewan and Central Manitoba. The interaction between this front and the low pressure triggered thunderstorms near the SK/AB, which ultimately led to this tornado.

According to Environment and Climate Change Canada (2018), an F0 tornado touched down near Schuler, AB. The path, time and width of the tornado was not documented by ECCC. No property damage was documented for this tornado.
Sources
NOAA Central Library. (2019). U.S. Daily Weather Maps. Friday May 23, 1980 [PDF]. Retrieved from https://library.noaa.gov/Collections/Digital-Collections/US-Daily-Weather-Maps
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/