|Edmonton tornado of 1987|
|Date:||July 31, 1987|
|Time:||3:25 p.m. MDT (2125 UTC)|
($581 million in 2013 dollars)
|Area affected:||Edmonton, Strathcona County, Sherwood Park|
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.
The tornado remained on the ground for an hour, cutting a swath of destruction 40 kilometres (25 mi) long and up to a kilometre (0.6 miles, or 3000 feet) 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 $332.27 million CAD ($581 million in 2013 dollars) 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. At least four other tornadoes were reported that day in central Alberta between Millet and Vegreville.
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, as well as for Leduc, Parkland, and Strathcona Counties. 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. At one point the tornado came close to the building that housed the Alberta weather office, where several employees were forced to take cover.
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 and killed 12 people and injuring numerous others. The tornado dissipated shortly after.
The following is a chronology of events that occurred on July 31, 1987.
||This section needs additional citations for verification. (July 2012)|
While municipal emergency agencies, fire departments, ambulance and police were responding, Canada's Department of National Defence placed helicopters and ambulances on standby at the 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.
This tornado has been under scrutiny by Environment Canada in recent years, as to whether or not it could be considered for an F5 rating. If done this would make it the earliest such tornado since records have been kept, next to the Elie, Manitoba tornado. The tornado's maximum recorded wind speed was 416 km/h (258 mph). The wind speed for an F5 tornado is 419 km/h (260 mph).
|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 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)
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