It was a day that came to be known as “Black Friday”. On July 31, 1987, one of the most powerful tornadoes in Canadian history struck Edmonton, Alberta and parts of Strathcona County. It is the deadliest known tornado for Alberta and the second-deadliest for the country. This significant tornado was given a rating of F4 with maximum winds estimated at 260 mph. This tragic event led to the development of Alberta’s Emergency Public Warning System (EPWS), which would be implemented in 1992. Read the full summary here!