|Formed||31 July 1987|
|Dissipated||31 July 1987|
|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 (14:55-22:00UTC)|
|Largest hail||Tennis ball and larger|
|Maximum rainfall||300 millimetres (12 in)|
($615 million in 2017 dollars)
|Areas affected||City of Edmonton, Edmonton Capital Region, Central Alberta|
1Most severe tornado damage; see Fujita scale 2Time from first tornado to last tornado
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 part 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.
The tornado remained on the ground for an hour, cutting a swath of destruction 30.8 kilometres (19.1 mi) long and up to a 1,300 metres (0.81 mi) wide in places, and peaking at F4 on the Fujita scale. The tornado killed 27 people, injured more than 300 people, destroyed more than 300 homes, and caused more than CAD332.27 million 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 one of the worst in Canada's history.
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.
In the week preceding July 31, a low pressure system sitting over southwestern British Columbia fed warm, humid air into central Alberta. Daytime heating along with near-record dewpoints over Alberta triggered a series of strong thunderstorms that persisted throughout the week. On July 31, a cold front developed over western Alberta, colliding with the warm moist air that persisted over the region. Forecasters recognized the elevated risk for severe weather early in the day. Weatheradio broadcasts and interviews with the media stressed "vicious thunderstorms" and "extremely strong and violent thunderstorms".
Severe thunderstorms developed rapidly over the foothills early in the day and quickly moved eastward. The first severe weather watches were issued over central Alberta late in the morning and continued early in the afternoon. At 1:40 PM, a severe weather watch was issued for the Edmonton area, including Leduc County, Parkland County, and Strathcona County. The watch was later upgraded to a warning at 2:45 PM as the line of storms approached the area. As the cluster of storms approached the Leduc area, a violent cell rapidly developed ahead of the main line of storms and sharply turned northward.
The storm passed east of Leduc, where the first tornado report made by a weather spotter at 2:59 PM. The tornado was on the ground briefly before dissipating. Shortly after 3 PM, the tornado again touched down in the Beaumont area, tossing granaries and farm equipment as it grew in size and strength.
At 3:04 PM, a tornado warning was issued for the city. The tornado moved into the southeast portion of the city as a multiple-vortex tornado, and tracked north along the eastern portions of Mill Woods, causing F2 to F3 damage. The tornado continued northward crossing the Sherwood Park Freeway and eventually hitting the Refinery Row area at F4 intensity. The tornado tossed several large oil tanks, leveled several industrial buildings, and several trailers were picked up and scattered at Laidlaw and Byers Transport. Grass scouring and windrowing of debris occurred, and damage in that area may have been borderline F5, but was never officially ranked as such.
The tornado weakened slightly as it passed over an open area between Baseline Road and the North Saskatchewan River. Still, it maintained F2 to F3 intensity as it tore through eastern parts of Clareview toward 4:00 PM, causing heavy damage to several homes in Kernohan, Bannerman and Fraser neighbourhoods. The tornado persisted as it headed northeast toward the Evergreen Mobile Home Park. There, the tornado completely destroyed nearly 200 mobile homes in the area, killed 15 people and injured numerous others.
Another F2 tornado touched down south of Edmonton, near Beaumont and moved east of the city through countryside and a F1 touched down in Southeast Edmonton in mostly farmland, twenty-two minutes after the first tornado touchdown. traveling 7.26 kilometres (4.51 mi)Four F0 tornadoes; north, northwest, and southwest, but were too far away to be seen from the city. In the Edmonton Area and Central Alberta, four F0 tornados, a F2 between Millet and Vegreville, lasting on the ground for 52 kilometres (32 mi), causing $40,000 in damages. Totaling in eight touchdowns on the 31st.
Chronology of events
The following is a chronology of events that occurred on July 31, 1987.
- 1:40 pm Severe weather watch issued for the City of Edmonton, Leduc County, Parkland County and Strathcona County
- 2:45 pm Severe weather warning issued for same area
- 2:52 pm Weatheradio Canada emergency tone activated for Edmonton transmitter
- 2:59 pm Tornado sighting reported to weather office by a citizen near Leduc, 33 km (21 mi) south of downtown Edmonton
- 3:04 pm Tornado warning issued over Weatheradio
- 3:25 pm Tornado causes F2 - F3 damage in the southeast Mill Woods, a suburban residential area
- 3:30 pm Peak intensity: F4 damage in Refinery Row, a heavy industrial area, killing 12 people and injuring numerous others
- 4:25 pm Tornado causes F2 - F3 damage in Evergreen, a manufactured home community, killing 15 people and injuring numerous others, and then dissipates
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While municipal emergency agencies, fire departments, ambulance and police were responding, Canada's Department of National Defence placed helicopters and ambulances on standby at Canadian Forces Base Edmonton, and provided reconnaissance flights for the City of Edmonton and the deputy prime minister.
At the onset of the storm Emergency Preparedness Canada established contact with the Government of Alberta Emergency Response Centre. EPC established a liaison office at the response centre at approximately 1800 hours that same day.
As emergency personnel responded to the industrial area, potential threats from dangerous goods came to light. Alberta's Compliance Information Centre dispatched its dangerous goods inspectors and the provincial environmental response team to the area.
The emergent post-disaster response period lasted for approximately three weeks including immediate disaster assistance for victims. At the end of August 1987 details of the overall damage costs were gathered and the Government of Alberta announced an extensive disaster recovery program with the assistance of the Government of Canada.
The Emergency Public Warning System, later replaced by Alberta Emergency Alert, was developed as a result of the 1987 tornado disaster. The warning system breaks into private and public broadcasts on radio, television and cable systems. It alerts the public for all disaster hazards that threaten to strike with little or no warning. The warning system is also used for issuing Amber Alerts.
The tornado had also resulted in the first implementation of the Doppler weather radar concept in Canada in the early 1990s. Edmonton's Carvel radar was one of only three Dopplers to exist in Canada at the time. It later became part of the Canadian weather radar network, which was Dopplerized starting in 1998.
In popular culture
- List of tornadoes and tornado outbreaks
- Tornado myths
- Canadian inflation numbers based on Statistics Canada. "Consumer Price Index, historical summary". CANSIM, table (for fee) 326-0021 and Catalogue nos. 62-001-X, 62-010-X and 62-557-X. And Consumer Price Index, by province (monthly) (Canada) Last modified 2016-01-22. Retrieved March 2, 2016
- "Hourly Data Report for July 31, 1987 - Station pressure (kPa)". Environment Canada. Government of Canada. Retrieved 28 August 2016.
- ITV (Global News Edmonton) (1987). "Winds of Terror" (Video). Alberta Municipal Affairs. Edmonton: Government of Alberta. Retrieved 10 May 2016.
- "Reported Hail-Size Category". University of Alberta. University of Alberta. Retrieved 10 May 2016.
- "Canadian National Tornado Database: Verified Events (1980-2009) - Public". Open Canada. Environment Canada. Retrieved 21 August 2016.
- "Fact Sheet - Summer Severe Weather Warnings". Environment Canada. 2005-05-24. Archived from the original on 2009-02-28. Retrieved 2007-07-30.
- "Winds of Terror". Retrieved 16 May 2012.
- "The Edmonton Tornado - Environment Canada (archive.org)". Archived from the original on 2002-11-15.
- "The Edmonton Tornado". Retrieved 16 May 2012.
- "A Commemorative Reflection on the Edmonton Tornado and Hailstorm, 1987". Retrieved 16 May 2012.
- "Chapter 3 -J Other tornadoes in greater Edmonton". A Commemorative Reflection On The Edmonton Tornado And Hail. Retrieved 23 June 2016.
- "Program History". Alberta Emergency Alert. Government of Alberta. Retrieved November 11, 2012.
- "Alberta launches 'Amber Alert' kidnap system". Canadian Press. CTV.ca. December 2, 2002. Retrieved July 30, 2012.[dead link]
- Joe, Paul; Lapczak, Steve (2002). "Evolution of the Canadian Operational Radar Network" (PDF). Proceedings. 2nd European Conference on Radar in Meteorology and Hydrology. Delft, Netherlands. pp. 370–382. Retrieved 1 March 2016.
- "Exclusive premiere: The Rural Alberta Advantage "Tornado '87"". IFC. November 11, 2011.
- Univ of Alberta Library
- CBC Broadcast Archive
- Tornadoes in Canada, CBC.ca
- Photos of the Edmonton tornado
|10 deadliest Canadian tornadoes|
|1||Regina Cyclone||June 30, 1912||≥28|
|2||Edmonton tornado||July 31, 1987||27|
|3||Windsor–Tecumseh, Ontario tornado||June 17, 1946||17|
|4||Pine Lake, Alberta tornado||July 14, 2000||12|
Windsor, Ontario tornado
|August 16, 1888
April 3, 1974
|7||Barrie, Ontario tornado||May 31, 1985||8|
|=8||Sudbury, Ontario tornado
Sainte-Rose, Quebec tornado
|August 20, 1970
June 8, 1953
|=10||Bouctouche, New Brunswick tornado
Portage la Prairie, Manitoba tornado
|August 6, 1879
June 22, 1922
Sources: Environment Canada (PDF)