Based on storm observations over the past century, many believe that Canada experiences the most tornadoes annually of any country excluding the United States. The belief has merit since Canada shares a long east–west border with the US and experiences many of the same conditions that form tornadoes as their neighbors to the south, particularly in the Great Lakes Basin. Unlike many of the countries in Asia and Europe, Canadians have long been aware of the threat of tornadoes during the spring and summer months when hot and humid air moving from the south can produce an explosive storm situation.
Canadian Tornado Climatology
The tornado statistics produced by Environment Canada tell us an average of 80 tornadoes strike the nation annually, and these tornadoes kill two and injure twenty each year with damages in the tens of millions of dollars. These numbers are based on reported storms verified as tornadoes by Environment Canada scientists and may be an under-reporting of the actual number of tornado touchdowns as Canada still has large tracts of land sparsely populated and unmonitored. In such regions, a tornado may strike and never be seen. But with increases in population, better observation techniques and increased awareness of severe weather including a bevy of storm chasers roaming the countryside it would not be surprising to see a marked increase in the number of reported tornadoes over the coming years. Based on events in more recent years, the average annual number may be closer to 100 tornadoes annually, and perhaps even higher.
Average Number of Tornadoes per Year in Across Canada Diagram courtesy Natural Resources Canada
The most likely months for tornadoes to strike in Canada are from May to September with the peak months being June and July. Most tornadoes form in the afternoon and early evening. Unlike the US, winter tornadoes in Canada are rare but they have occurred.
Average Percentage of Annual Tornadoes by Month Across Canada
Most tornadoes are reported in the central portions of the nation away from the coasts. Ontario experiences the most tornadoes annually, on average, about 32 percent of Canadian twisters. Alberta and Saskatchewan report about 22 to 23 percent of the tornadoes. Manitoba tallies about 13 percent and Quebec about 7 percent of the annual tornado count. British Columbia experiences 1.4 percent of the annual total. The Maritimes as a group (New Brunswick, Nova Scotia, Prince Edward Island) and Newfoundland and Labrador account for the remaining 1.5 percent of the total.
Average Percentage of Annual Tornadoes by Province Across Canada
Many of the tornadoes that strike southern Ontario and southwestern Quebec arise from organized convective storm systems that move into those provinces from Michigan, Ohio and New York. Recent studies from Project ELBOW suggest that some southwestern Ontario tornadoes form along the lake breeze fronts moving from the Great Lakes, particularly Lakes Huron and Erie. Such tornadoes are usually weak compared with the tornadoes arising from large convective complexes moving up from the US.
Canada, like the United States used the Fujita Scale (F-scale), and now apply the new enhanced Fujita scale (EF-scale) to assess tornado strength based on damage assessment. Unlike the US, violent tornadoes those with F4/F5 ratings are rare in Canada. Since regular assessments using the F-scale began in Canada, nine tornadoes have been rated F4 seven in Ontario and two in western Canada and only one has been designated as F5. In the US, about one percent of tornadoes are rated F4/F5.
Watches and Warnings
Like the United States, Environment Canada uses a two-phase warning system for such tornadic storms. A tornado watch is issued when "Conditions are favourable for the development of tornadoes within the areas and times specified in the watch." Residents are urged to "Be prepared to take shelter, preferably in the lower level of a sturdy building."
A tornado warning is issued when: "One or more tornadoes are occurring in the area specified." "The expected motion, development and duration will be given in the warning. If you are in the path of a tornado, take emergency precautions immediately. If you are near the area specified in the warning, be alert for the development of additional tornadoes or severe thunderstorms."
Individual Tornado Events and Oddities
The following summary highlights tornado events of historical importance or with a strange circumstance. It is not intended to be a complete record. Note that some tornadoes prior to the 1970s have been assigned an F-scale value based on contemporary records of damage.
The first recorded tornado on "Canadian" soil struck the Niagara Peninsula between the current communities of Fonthill and Port Robinson on 30 June 1792. "A violent hurricane passed over the southwestern portion of the township, levelling all the houses in its path, but at the same time uprooting the trees, thus effectually clearing the woods." (Jubilee History of Thorold, 1898) The path of destruction through the woods was turned into a roadway between the communities. Known as Hurricane Road the term tornado did not have its current meaning then it is still in use today.
The second recorded twister hit my former home of Guelph, Ontario on 2 June 1829. I have written a detailed account of that storm elsewhere on this site (click here).
The first recorded death from a tornado in Canada occurred in Galt (now part of Cambridge), Ontario on 7 August 1844.
Tornado approaching Vulcan, Alberta, 8 July 1927 Photo courtesy NOAA Historical Photo Collection, US Department of Commerce
A 200-m (219 yards) wide tornado striking near Listowel, Ontario on 10 June 1880, lofted a man into the air. He saved himself by grabbing onto a bridge.
A tornado, or family of tornadoes, rampaged from Cornwall, Ontario to Montreal, Quebec on 6 June 1888 destroying 500 farmsteads, barns and outbuildings. Three died.
The Regina (Saskatchewan) Cyclone of 30 June 1912 was the first major tornado reported west of Ontario. The F4 tornado was Canada's most deadly to date and remains so in 2008.
Destruction resulting from tornado striking Regina SK on 30 June 1912. Photo courtesy Library and Archives Canada
Based on damage reports, meteorologists have assigned a strong F4, possibly a weak F5, rating to the tornado that struck Benson, Saskatchewan on 1 July 1935.
The latest tornado on the calendar in Canadian annuals hit the Ontario community of Exeter on 12 December 1946.
An unusual (for Canada) winter tornado hit White Point Beach, near Liverpool, Nova Scotia on 30 January 1954. It is also the earliest calendar tornado on record.
On 7 March 1966, a tornado hit the Pacific coastal town of Ucluelet, British Columbia causing significant damage.
A funnel cloud appeared over Upper Garry Lake, Northwest Territories (now Nunavut) on 10 August 1973. It is the most northerly observation of a funnel cloud in Canadian records.
A tornado toppled a tower near the community of Yellowknife, Northwest Territories on 30 July 1978. Skipping across the countryside, it then ripped up a transmission tower at Rae-Edzo five kilometres distant. It wass the third tornado reported here since 1960.
A major tornado outbreak struck southwestern Ontario in the vicinity of Woodstock on 7 August 1979. The outbreak included two nearly simultaneous F4 storms that raged through Woodstock and one F3 storm in nearby Stratford. The 1-km wide tornado that struck the west side of town heavily damaged the Dominion Food Store and Dickson's Florist. The second F4 rampaged across the south side of town destroying the Maranatha Christian Reformed Church and the John Knox Christian School. The twisters levelled many homes leaving only foundations and rubble and tossed cars around like toys. After the tornadoes left Woodstock, in the 2 minutes it took to pass over, one nearly wiped the town of Oxford Centre, a small community of 250, off the map. A similar fate fell on the towns of New Durham and Vanessa. In total, over a thousand people were left homeless after the tornadoes rendered 350 homes uninhabitable. Miraculously, only two people died one when his truck was blown off the highway; another hit by flying debris and 142 were injured.
The deadly tornado that struck Barrie, Ontario on 31 May 1985 passed just south of the Barrie Racetrack where it heavily damaged the grandstand and destroyed several barns. Eye witnesses claim they saw one horse lifted off the ground and gently placed down some distance away. The horse was subsequently nicknamed "Twister Resistor."
A family of eight tornadoes touched down in central Saskatchewan on 19 June 1989. Winds and hail shredded crops at Blaine Lake, Saskatchewan.
Later that summer, 14 August 1989, three tornadoes touched down in New Brunswick. One uprooted trees and demolished a barn near Carlisle, but amazingly all but two of 24 glass storm windows stored inside were undamaged.
Winds associated with a strong thunderstorm with unsubstantiated reports of a funnel cloud struck Thorold, Ontario on the afternoon of 20 May 1996, damaging one of the four screens of a drive-in theatre. Ironically the movie to be shown that night was Twister. Some media reports claimed that a weak tornado struck the drive-in during the showing of the movie, but the storm actually hit well before dark. There was perhaps confusion as a small tornado did touch down in the nearby town of Stoney Creek that evening.
As people were gathering on 6 August 2000 in Pine Lake, Alberta for a memorial service for those killed in the Pine Lake tornado a few weeks earlier, a weak tornado formed nearby.
Many waterspouts are tornadoes that form or move over bodies of water. Over a period of about a week (late September to early October) in 2003, the Great Lakes basin was the scene of an unprecedented outbreak of waterspouts. Environment Canada meteorologist Wade Szilagyi estimated over 66 waterspouts danced over the unseasonably warm lake waters overlain by a cold air mass and strong upper level trough. It was the largest outbreak of waterspouts ever observed.
On 19 May 2004, two significant tornadoes formed over southwestern Ontario within minutes of each other and separated by only a few kilometres. The first struck at Gads Hill, near Stratford. It was believed to have been the strongest tornado to hit Ontario in eight years. This strong F3 tornado tore the roof off a farm house and most of its second floor, damaged the silo and demolished a barn. Several injured cattle had to be destroyed. The second, an F2 storm, touched down in the southern sections of Mitchell, tearing off roofs, damaging homes and flipping a pickup truck.
An outbreak of tornadoes struck southern Ontario on 19 August 2005 causing damage along a path from Stratford to Oshawa, and extending north to Georgian Bay near Collingwood. Three confirmed tornadoes skipped across the region. The storm cell moving just north of Fergus spawned two F2 tornadoes causing extensive damage. These twisters damaged houses in Kitchener, Guelph and near Fergus. The first of the F2 tornadoes trekked from Milverton to Conestogo Lake (west of Elmira). The second tracked from Salem to Lake Bellwood (north of Guelph). These two twisters uprooted hundreds of trees, downed power lines, tossed cars and trucks like toys, and ripped apart several homes, cottages and barns. The storm left a damage trail that the Insurance Bureau of Canada reported was the highest insured loss in the province's history, exceeding $500 million, more than two and a half times Ontario's losses during the infamous ice storm of 1998.
On a weird weather day in Southern Ontario (9 November 2005), a line of storms dumped every kind of weather on the region from Windsor to Ottawa. Ottawa reported freezing rain, Barrie had snow, and Hamilton experienced a rare November tornado. The F1 twister struck about 4 pm and lasted but ten minutes, slicing a narrow 7-km path through the city. It caused extensive damage to some homes and other buildings and lifted a school gym's roof off its foundation, but miraculously only two children suffered minor injuries.
An F1 tornado struck the Mitchell, Ontario area on May 15, 2007, causing minor damage. It was the third tornado to hit the Mitchell area in a three-year span.
An F5 tornado seen from the Southeast as it approaches Elie, MB on June 22, 2007. Photo credit: Justin Hobson
Canada's first documented F5 tornado hit Elie, Manitoba on 22 June 2007. Video of the storm indicated it threw an almost intact house several hundred metres before the structure disintegrated and fell to earth. Moments later, the twister hurled a heavy van through the air and deposited it in an open field. This tornado roared across the Manitoba countryside for about 35 minutes, travelling a distance of about 5.5 km. The storm path was approximately 300 metres wide. At its most intense, the Elie tornado's winds were likely in the 417 to 509 km/h (261-318 mph) range. Fortunately, there were no fatalities nor serious injuries from this storm.
On 29 July2007, a weak F0 tornado touched down at Gander Bay, Newfoundland and Labrador. It moved from Wing's Point, to Main Point, flipping a few skidoo trailers.
Canada's Worst Tornadoes
Canada's ten deadliest individual tornadoes (to 2008) have been:
Regina, Saskatchewan, June 30, 1912: 28 dead, hundreds injured
Edmonton, Alberta, July 31, 1987: 27 dead, 300 injured. Damage of $300 million.
Windsor, Ontario, June 17, 1946: 17 dead, hundreds injured
Pine Lake, Alberta, July 14, 2000: 12 dead, 140 injured
Valleyfield, Quebec, August 16, 1888: 9 dead, 14 injured
Windsor, Ontario, April 3, 1974: 9 dead, 30 injured
Barrie, Ontario, May 31, 1985: 8 dead, 155 injured
Sudbury, Ontario, August 20, 1970: 6 dead, 200 injured
St-Rose, Quebec, June 14, 1892: 6 dead, 26 injured
Buctouche, New Brunswick, August 6, 1879: 5 dead, 10 injured
The final observation on Canadian tornadoes, I will leave to the famed Canadian artist Tom Thomson. Thomson was a friend and colleague of a group of Canadian painters who redefined the painting landscape (pun intended) of Canada in the early days of the Twentieth Century. The groups would become The Group of Seven in the years following Thomson's death. Many of their early works were painted outdoors (plein air) in the regions north of Toronto, Ontario.
Thunderhead by Tom Thomson
Thomson would often paint sketches of the wilderness landscapes from his canoe on pine boards. Thomson was an astute and accurate observer of his surroundings, and that included the prevailing weather. Phil Chadwick, a Canadian meteorologist and accomplished plein air painter himself, has looked closely at Thomson's work in what he calls CSI creative scene investigation.
Among Thomson's many sky scenes is one entitled (by others after his death) Thunderhead painted in Algonquin Park during the summer of 1912 or 1913. But on closer inspection, Chadwick feels that this is not just a mere thunderhead or cumulonimbus cloud but a supercell producing a tornado. Chadwick points out that the details Thomson painted in his cloud very closely match those in a tornado-producing supercell. Thomson may not have known what he was painting, but he was an astute observer of the scene before him, and Chadwick's argument, supported by photographs of similar clouds, is persuasive. Unfortunately we have no supporting records to confirm or refute this claim. But as an unabashed fan of Tom Thomson, I am glad to include him as a chronicler of Canadian tornadoes.
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