Edmonton tornado

The Edmonton tornado of 1987
F4 tornado
Formed July 31, 1987 (1987-07-31)
Dissipated July 31, 1987 (1987-07-31)
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)
Highest winds
Largest hail Tennis ball and larger
Maximum rainfall 300 millimetres (12 in)
Damage $332.27 million
($633 million in 2017 dollars[1] )
Power outages Yes
Total fatalities 27 fatalities
~300 injured
Areas affected City of Edmonton, Edmonton Capital Region, 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 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.[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 kilometres (19.1 mi) in length and up to 1.3 kilometres (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 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.

Summary

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.[7] Weatheradio broadcasts and interviews with the media stressed "vicious thunderstorms" and "extremely strong and violent thunderstorms".[8] 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 3:00 pm, the tornado again touched down in the Beaumont area, tossing granaries and farm equipment as it grew in size and strength.[9]

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.[10] Grass scouring and windrowing of debris occurred, and damage in that area may have been borderline F5, but was never officially ranked as such.[11]

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.[10] 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.

Other area tornadoes

Not including the F4 tornado seven other tornadoes were reported. An F2 tornado touched down near Beaumont, south of Edmonton. It travelled through countryside east of Edmonton. Twenty-two minutes after the first tornado touchdown an F1 tornado touched down in Southeast Edmonton in an area that was mostly farmland. It travelled 7.26 kilometres (4.51 mi). There were also four F0 tornadoes In the Edmonton Area (to the north, northwest, and southwest) but too far away to be seen from the city. [5][12]

Farther from the Edmonton area an F2 tornado between Millet and Vegreville and remained on the ground for 52 kilometres (32 mi), causing $40,000 in damages.[13][5]

July 31, 1987 confirmed tornadoes[5]
F0F1F2F3F4F5
412010

Chronology of events

Path of the tornado

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[6] 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

Post-disaster response

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.[14] 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.[15]

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.[16]

The song "Tornado '87" by The Rural Alberta Advantage, on their 2011 album Departing, was inspired by singer Nils Edenloff's experience as a child surviving the tornado.[17]

See also

References

  1. ↑ Canadian inflation numbers based on Statistics Canada. "Consumer Price Index, historical summary". Statistics Canada. Retrieved April 26, 2018. 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)". Statistics Canada. Retrieved April 26, 2018.
  2. ↑ "Hourly Data Report for July 31, 1987 - Station pressure (kPa)". Environment Canada. Government of Canada. Retrieved August 28, 2016.
  3. ↑ ITV (Global News Edmonton) (1987). "Winds of Terror" (Video). Alberta Municipal Affairs. Edmonton: Government of Alberta. Retrieved May 10, 2016.
  4. ↑ "Reported Hail-Size Category". University of Alberta. University of Alberta. Retrieved May 10, 2016.
  5. 1 2 3 4 5 6 "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.
  6. 1 2 "Fact Sheet - Summer Severe Weather Warnings". Environment Canada. May 24, 2005. Archived from the original on February 28, 2009. Retrieved July 30, 2007.
  7. ↑ "Winds of Terror". Retrieved May 16, 2012.
  8. ↑ "The Edmonton Tornado - Environment Canada (archive.org)". Archived from the original on November 15, 2002.
  9. ↑ "The Edmonton Tornado". Retrieved May 16, 2012.
  10. 1 2 "A Commemorative Reflection on the Edmonton Tornado and Hailstorm, 1987". Archived from the original on December 5, 1998. Retrieved May 16, 2012.
  11. ↑ by Max (2012-07-16). "Powerful Tornadoes Outside the United States – Violent Tornadoes in France, Russia, South Africa, Poland, Canada and Japan |". Extremeplanet.me. Retrieved 2017-07-31.
  12. ↑ "Chapter 3 -J Other tornadoes in greater Edmonton". A Commemorative Reflection On The Edmonton Tornado And Hail. Retrieved June 23, 2016.
  13. ↑ "The Edmonton Tornado - Environment Canada (archive.org)". Archived from the original on 2002-11-15.
  14. ↑ "Program History". Alberta Emergency Alert. Government of Alberta. Retrieved November 11, 2012.
  15. ↑ "Alberta launches 'Amber Alert' kidnap system". Canadian Press. CTV.ca. December 2, 2002. Archived from the original on May 24, 2003. Retrieved July 30, 2012.
  16. ↑ 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 March 1, 2016.
  17. ↑ "Exclusive premiere: The Rural Alberta Advantage "Tornado '87"". IFC. November 11, 2011.
  • "University of Alberta Libraries". Archived from the original on January 1, 2013.
  • CBC Broadcast Archive
  • Tornadoes in Canada, CBC.ca
  • Photos of the Edmonton tornado
  • CTV News' YouTube video of Edmonton Tornado

Coordinates: 53°34′N 113°22′W / 53.56°N 113.36°W / 53.56; -113.36

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