| F4 tornado | |
|---|---|
 Photograph by Steve Simon | |
| Formed | July 31, 1987 |
| Duration | 2:55 p.m. to 8:00 p.m. MDT (20:55-02:00UTC) |
| Highest winds |
|
| Lowest pressure | 919.3 mb (27.15 inHg) |
| Max. rating1 | F4 tornado |
| Duration of tornado outbreak2 | 2:55 p.m. to 8:00 p.m. MDT (20:55-02:00UTC) |
| Largest hail | Tennis ball and larger |
| Maximum rainfall | 300 millimetres (12 in) |
| Fatalities | 27 fatalities ~300 injured |
| Damage | $332.27 million ($762 million in 2023 dollars[1]) |
| Areas affected | City of Edmonton, Strathcona County, Central Alberta |
| 1Most severe tornado damage; see Fujita scale 2Time from first tornado to last tornado [2][3][4][5] | |
The Edmonton tornado of 1987, an event also known as Black Friday to Edmontonians, was a powerful and devastating tornado that ripped through the eastern parts of Edmonton, Alberta, Canada and parts of neighbouring Strathcona County on the afternoon of Friday, July 31, 1987. It was one of seven other tornadoes in central Alberta the same day.[5]
The tornado peaked at F4 on the Fujita scale and remained on the ground for an hour, cutting a swath of destruction 30.8 km (19.1 mi) in length and up to 1.3 km (0.81 mi) wide in some places.[5][6] It killed 27 people, and injured more than 300, destroyed more than 300 homes, and caused more than C$332.27 million (equivalent to $762 million in 2023) in property damage at four major disaster sites. The loss of life, injuries and destruction of property made it the worst natural disaster in Alberta's recent history and the second deadliest in Canada's history, after the Regina Cyclone.
Weather forecasts issued during the morning and early afternoon of July 31, 1987, for Edmonton revealed a recognition by Environment Canada of a high potential for unusually severe thunderstorms that afternoon. Environment Canada responded swiftly upon receipt of the first report of a tornado touchdown from a resident of Leduc County which is immediately adjacent to Edmonton's southern boundary.
- ^ 1688 to 1923: Geloso, Vincent, A Price Index for Canada, 1688 to 1850 (December 6, 2016). Afterwards, Canadian inflation numbers based on Statistics Canada tables 18-10-0005-01 (formerly CANSIM 326-0021) "Consumer Price Index, annual average, not seasonally adjusted". Statistics Canada. Retrieved April 17, 2021. and table 18-10-0004-13 "Consumer Price Index by product group, monthly, percentage change, not seasonally adjusted, Canada, provinces, Whitehorse, Yellowknife and Iqaluit". Statistics Canada. Retrieved May 8, 2024.
- ^ "Hourly Data Report for July 31, 1987 - Station pressure (kPa)". Environment Canada. Government of Canada. Archived from the original on December 14, 2018. Retrieved August 28, 2016.
- ^ ITV (Global News Edmonton) (1987). "Winds of Terror". Alberta Municipal Affairs. Edmonton: Government of Alberta. Archived from the original (Video) on January 15, 2013. Retrieved May 10, 2016.
- ^ "Reported Hail-Size Category". University of Alberta. Retrieved May 10, 2016.
- ^ a b c "Canadian National Tornado Database: Verified Events (1980-2009) - Public". Open Canada. Environment Canada. Archived from the original on July 4, 2016. Retrieved August 21, 2016.
- ^ "Fact Sheet – Summer Severe Weather Warnings". Environment Canada. May 24, 2005. Archived from the original on February 28, 2009. Retrieved July 30, 2007.