Woodstock, Ontario Tornado of August 1979
Encyclopedia
On the evening of August 7th, 1979 at least three tornadoes
Tornado
A tornado is a violent, dangerous, rotating column of air that is in contact with both the surface of the earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. They are often referred to as a twister or a cyclone, although the word cyclone is used in meteorology in a wider...

 touched down in southwestern Ontario, devastating scores of farms and homes in the Woodstock
Woodstock, Ontario
Woodstock is a city and the county seat of Oxford County in Southern Ontario, Canada. Woodstock is located 128 km southwest of Toronto, north of Highway 401 along the historic Thames River...

 area. The southern end of that city suffered some of the most intense destruction along with several other nearby towns in Oxford County
Oxford County, Ontario
Oxford County is a regional municipality and census division of the Canadian province of Ontario, located in the Southern portion of the province. The regional seat is in Woodstock...

, the result of an F4 tornado. Two people died, 142 were injured, and hundreds of homes suffered significant damage. Overall monetary losses totaled an approximate $100 million in 1979 Canadian dollars.

Meteorological synopsis

A relatively cool and dry airmass
Airmass
In astronomy, air mass is the optical path length through Earth’s atmosphere for light from a celestial source. As it passes through the atmosphere, light is attenuated by scattering and absorption; the more atmosphere through which it passes, the greater the attenuation. Consequently, celestial...

 was being pushed in from the north by means of a cold front
Surface weather analysis
Surface weather analysis is a special type of weather map that provides a view of weather elements over a geographical area at a specified time based on information from ground-based weather stations...

, into warm and unstable air from the southern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. Severe weather
Severe weather
Severe weather phenomena are weather conditions that are hazardous to human life and property.- Examples Include :Severe weather can occur under a variety of situations, but three characteristics are generally needed: a temperature or moisture boundary, moisture, and , instability in the...

 had already affected northeastern Ontario
Northeastern Ontario
Northeastern Ontario is the region within the Canadian province of Ontario which lies north and east of Lakes Superior and Huron.Northeastern Ontario consists of the districts of Algoma, Sudbury, Cochrane, Timiskaming, Nipissing and Manitoulin; and the single-tier municipality of Greater...

 the evening before with this same cold front. During the late morning of the 7th the front had stalled across the Bruce Peninsula
Bruce Peninsula
The Bruce Peninsula is a peninsula in Ontario, Canada that lies between Georgian Bay and the main basin of Lake Huron. The peninsula extends roughly northwestwards from the rest of Southern Ontario, pointing towards Manitoulin Island, with which it forms the widest strait joining Georgian Bay to...

, where newer convection
Atmospheric convection
Atmospheric convection is the result of a parcel-environment instability, or temperature difference, layer in the atmosphere. Different lapse rates within dry and moist air lead to instability. Mixing of air during the day which expands the height of the planetary boundary layer leads to...

 produced a couple of weak F1 tornadoes near the towns of Wiarton
Wiarton, Ontario
Wiarton is a community in Bruce County, Ontario, at the western end of Colpoys Bay, an inlet off Georgian Bay, on the Bruce Peninsula. The community is part of the town of South Bruce Peninsula, Ontario....

 and Tara
Tara, Ontario
Tara is an unincorporated community in southwestern Ontario, Canada. At the 2006 census, it had 989 residents and 435 dwellings. Within the municipality of Arran-Elderslie, it is a designated place located on the Sauble River, with an area of 2.39 km², and an urban area that covers...

. It has been speculated that a large outflow boundary
Outflow boundary
An outflow boundary, also known as a gust front, is a storm-scale or mesoscale boundary separating thunderstorm-cooled air from the surrounding air; similar in effect to a cold front, with passage marked by a wind shift and usually a drop in temperature and a related pressure jump...

 associated with these particular storms may have interacted with the lake breeze fronts, thus resulting in the Woodstock and Stratford tornadic supercell
Supercell
A supercell is a thunderstorm that is characterized by the presence of a mesocyclone: a deep, continuously-rotating updraft. For this reason, these storms are sometimes referred to as rotating thunderstorms...

s later that day.

The Ontario Storm Prediction Centre in Toronto issued a severe thunderstorm watch for southwestern Ontario at 3:40pm. The first thunderstorms of the afternoon began forming over Lake Huron before coming ashore in southern Bruce County (Toll, 1980). Storm motion was primarily to the southeast, and as these storms quickly began to intensify, reports of large hail began to pour in. A severe thunderstorm warning was issued at 6:15pm for Oxford, Perth County and Waterloo Region (Toll, 1980). A broken line of intense thunderstorms propagated toward Highway 401 with the two most intense storms located near Stratford and Embro. At this point, a tornado touchdown was mere minutes away as they began to morph into the powerful supercell variety, possibly a result of convergence along the Lake Erie and Lake Huron breeze fronts.

Stratford and Woodstock tornadoes

At 6:18pm, the supercell thunderstorm located near Stratford spawned a tornado a couple of kilometres south of that town. Moving to the southeast at approximately 60km/h, it quickly became stronger and as it passed north of Hickson some twenty minutes later, its path had widened to 1 kilometre as the tornado attained F4 intensity. Farm homes and outbuildings along the path were leveled by the tornado, although it didn’t pass over any towns directly. The path began to curve towards the east-northeast thereafter as the tornado began to weaken (Newark, 1979). It dissipated approximately four kilometres east of Bright at 6:56pm, after some 32 kilometres on the ground.

At around 6:52pm, a separate supercell thunderstorm northeast of Embro dropped a tornado near the village of Golspie
Zorra, Ontario
Zorra is a township in Oxford County, situated in south-western Ontario, Canada. A predominantly rural municipality, Zorra was formed in 1975 through the amalgamation of East Nissouri, West Zorra and North Oxford townships.-Government:...

. As it approached the city of Woodstock within the next ten minutes, the tornado quickly widened to over 1 kilometre and took on the appearance as a dark stovepipe or wedge tornado, not unlike those witnessed in the Midwestern United States
Midwestern United States
The Midwestern United States is one of the four U.S. geographic regions defined by the United States Census Bureau, providing an official definition of the American Midwest....

 (Grazulis, 1991). As many as 300 structures sustained damage in a four kilometre track from Ingersoll Road through Sixth Avenue to Parkinson Road and approaching Highway 401. A church and a school near the intersection of Highway 401 and Norwich Avenue were both destroyed (Toll, 1980). Trees that remained standing were partially debarked and, in a few instances, straw and other small objects were found embedded into the trunks. Among some of the other oddities were a pond in Southside Park that was reportedly sucked dry by the tornado, and a fourteen foot aluminum boat carried for almost a kilometre. Crossing Highway 401 it blew a tractor-trailer rig into the centre median, badly injuring the driver (Toll, 1980).

After the tornado left Woodstock, it is suspected that the tornado grew to its maximum size. As it passed over the town of Oxford Centre
Norwich, Ontario
The Township of Norwich is a municipality located in Oxford County in Southwestern Ontario, Canada. Preferred pronunciation of the town name is 'NOR-witch' , different from the city of Norwich, England, though its origin is more likely Norwich in Upper New York State, the area from which the...

 (a hamlet of 250 at the time) the damage path width had reached 2 kilometres. Within two minutes, thirty homes were destroyed, along with the local church and community centre in Oxford Centre (Toll, 1980). The towns of New Durham
Norwich, Ontario
The Township of Norwich is a municipality located in Oxford County in Southwestern Ontario, Canada. Preferred pronunciation of the town name is 'NOR-witch' , different from the city of Norwich, England, though its origin is more likely Norwich in Upper New York State, the area from which the...

 and Vanessa
Norfolk County, Ontario
Norfolk County is a rural city-status single-tier municipality on the north shore of Lake Erie in Southwestern Ontario, Canada. Bloomsburg is a small town located in Norfolk County and is the hometown of David Slater. The county seat and largest community is Simcoe...

 met a similar fate shortly thereafter, at 7:19 and 7:37pm respectively. A partially-filled, forty foot silo constructed of concrete six inches thick, toppled over on a farm somewhere between Oxford Centre and New Durham. The two deaths were in the New Durham area. A 51-year old man was killed instantly after being thrown some 200 feet from his two-ton vehicle, and a woman died after being hit with flying glass (Toll, 1980). At this point, the funnel had been on the ground for over twenty minutes and was easily over a mile wide. During this stretch of the tornado's path, two vehicles on two separate farms were tossed nearly a kilometre. In addition to the powerful tornado at hand, hail the size of tennis balls fell north of its track, destroying entire tobacco fields on dozens of farms (Newark, 1979). Eyewitnesses also reported that the tornado was preceded by intense and nearly constant lightning unlike any they had seen before (Toll, 1980).

Plowing southeastward, the tornado damaged several more homes in the north end of Waterford at 8:00pm before dissipating southeast of that town, after some 53 kilometres on the ground. Interestingly, as this tornado was at its maximum intensity somewhere between Oxford Centre and Vanessa, eyewitnesses reported seeing a satellite tornado, which accompanied the main circulation (Toll, 1980). On the ground for twenty kilometres, this satellite vortex was comparatively weaker (probably of F0 or F1 intensity) and paralleled the Woodstock tornado track as it moved southeast. All thunderstorm activity in southwestern Ontario ended by 9:30pm as the cold front moved south of Lake Erie.

Aftermath

Following the two violent tornadoes which hit Oxford County and surrounding area, over a thousand people were left homeless, 350 homes were rendered uninhabitable, and two people were dead in addition to 142 injuries. Farmsteads over a century old were completely wiped off the map in some instances. Given the immense amount of damage at hand, the number of people affected, and the relative lack of effective weather warnings, it is remarkable that so few were killed. In yet another remarkable twist, all manner of debris carried by the Woodstock tornado began appearing near the shores of Lake Erie (Toll, 1980). Canceled cheques, dollar bills, photographs, pieces of insulation, and even plywood were among some of the items discovered.

The city of Woodstock was enduring a recession
Recession
In economics, a recession is a business cycle contraction, a general slowdown in economic activity. During recessions, many macroeconomic indicators vary in a similar way...

 during the late 1970s and this tornado strained the already reduced municipal budget. Assistance manifested itself in a variety of ways during the following weeks and months. People made homeless found short-term residence with neighbours whose homes were less damaged. Ambulance
Ambulance
An ambulance is a vehicle for transportation of sick or injured people to, from or between places of treatment for an illness or injury, and in some instances will also provide out of hospital medical care to the patient...

s from all over the region (Kitchener
Kitchener, Ontario
The City of Kitchener is a city in Southern Ontario, Canada. It was the Town of Berlin from 1854 until 1912 and the City of Berlin from 1912 until 1916. The city had a population of 204,668 in the Canada 2006 Census...

, Tillsonburg, London
London, Ontario
London is a city in Southwestern Ontario, Canada, situated along the Quebec City – Windsor Corridor. The city has a population of 352,395, and the metropolitan area has a population of 457,720, according to the 2006 Canadian census; the metro population in 2009 was estimated at 489,274. The city...

, St. Thomas
St. Thomas, Ontario
St. Thomas is a city in southern , Ontario, Canada. It is the seat for Elgin County and gained its city charter on March 4, 1881.-History:...

, and Simcoe
Simcoe, Ontario
Simcoe is an unincorporated community and former town in Southwestern Ontario, Canada located near Lake Erie. It is the county seat and largest community of Norfolk County....

) converged on the towns and farms hit hardest by the tornadoes. Local Mennonite
Mennonite
The Mennonites are a group of Christian Anabaptist denominations named after the Frisian Menno Simons , who, through his writings, articulated and thereby formalized the teachings of earlier Swiss founders...

s also played a significant role in the rebuilding process, with hundreds working tirelessly each day to repair the farming communities of Oxford Centre, New Durham, and Vanessa.

The local government and those of surrounding counties sent thousands of dollars in relief. The city of Toronto donated $50,000 with Brant County sending $25,000 and the town of Stratford giving $10,000 (Toll, 1980). Businesses also set up food and clothing drives for those who lost their homes. Local radio stations set up a 10-hour radio segment called Operation Rebuild which raised almost half a million dollars, a relatively large amount of money for the time. The London Free Press distributed a booklet immortalizing the disaster, aptly titled Tornado. Over 50,000 copies were sold for $2.00 each. The Government of Ontario also granted $9 million in relief funds by the end of the year (Toll, 1980).

Comparison to other Ontario tornadoes

The Stratford and Woodstock tornadoes were both rated on the Fujita scale
Fujita scale
The Fujita scale , or Fujita-Pearson scale, is a scale for rating tornado intensity, based primarily on the damage tornadoes inflict on human-built structures and vegetation...

 as F4 tornadoes, the second-highest rating. Up until that time, an F4 tornado had not been recorded in southern Ontario since the May 1953 Sarnia Tornado. Following these 1979 tornadoes, there was another violent tornado outbreak in Barrie and Grand Valley six years later. As of 2011 there hasn’t been an F4 or higher storm that has struck southern Ontario. Comparing the 1953, 1979, and 1985 tornadoes, the Woodstock event was at least as damaging as the Sarnia one. In both instances, photographs display typical F4 damage to frame homes and farm outbuildings, where only piles of rubble remained.

While it is unlikely that the 1979 storm was as powerful as the 1946 Windsor-Tecumseh, Ontario tornado (where it has been speculated that F5 damage took place), the most glaring difference was that of path width. Whereas the damage paths of the 1946, 1953, and 1985 tornadoes remained under one kilometre, the Woodstock one was more massive in size. In some cases its width approached one mile, likely making it one of the largest tornadoes documented in Canada alongside the July 1987 Edmonton Tornado
Edmonton Tornado
The Edmonton Tornado, 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...

. Environment Canada
Environment Canada
Environment Canada , legally incorporated as the Department of the Environment under the Department of the Environment Act Environment Canada (EC) (French: Environnement Canada), legally incorporated as the Department of the Environment under the Department of the Environment Act Environment...

places the 1979 Woodstock tornado as the eleventh worst in the country's history.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK