Forty Years Since Black Friday: Looking Back at the Historic Tornado Outbreak and the Barrie F4 From May 31st 1985
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The damaged ‘welcome to Barrie’ sign following the f4 tornado that hit may 31st, 1985, courtesy of the Barrie Banner.
On this day in 1985, Southern Ontario experienced violent thunderstorms which produced an outbreak of 14 tornadoes, part of a larger outbreak of 44 tornadoes that also impacted Ohio, Pennsylvania, and New York. This stands as the third largest tornado outbreak in Canadian history and one of the tornadoes from that day was the 7th deadliest on record in Canada.
A total of 88 people lost their lives that day; 8 were in Barrie, two were in Grand Valley, two were in Tottenham, and the rest of the fatalities occurred in the US. Hundreds of people were left homeless across Southern Ontario and total damage from the 14 tornadoes is estimated at well over $100 million (in 1985 dollars).
It was all over in six hours and now, May 31st, 1985 is referred to as Black Friday.
The daily weather map from the morning of may 31st, 1985, Courtesy of the National Weather Service.
Meteorological Background
The day began with a low pressure system settled over Northern Minnesota and Wisconsin and an associated cold front stretching over Lake Superior and Michigan’s Upper Peninsula, then southward through Lake Michigan and into the Midwest. This system drew in warm, moist air from the Gulf and cool, dry air from the north. It was being driven by a strong upper-level jet stream so as the cold front rapidly swept eastward through the Gulf air mass, it triggered explosive development of severe thunderstorms.
The satellite loop below shows how the thunderstorms developed through the afternoon and evening across the region as the cold front swept through.
The Visible satellite loop from the afternoon of May 31st, 1985 showing the development of thunderstorms, courtesy of the National Weather Service.
Analysis of the upper air charts shows that winds at the 850mb level were 40 knots (74km/h) and at the 300mb level, they were 100 knots (185 km/h). The winds also changed direction with height which meant the atmosphere had plenty of both vertical speed shear and directional shear, which create rotation in thunderstorms and is a crucial ingredient in the formation of tornadoes.
Environment Canada saw this set up and they proactively issued a Severe Weather Watch at 7am, well ahead of the cold front. The storms started to develop over Lake Huron at 1:40pm and quickly intensified into a line of storms by 2:00pm. At 2:25pm, Environment Canada issued its first Severe Weather Warning of the day, which included the reminder that some severe thunderstorms produce tornadoes.
The line of storms continued to develop over the next couple of hours, travelling eastward at up to 70km/h, and the warnings were subsequently expanded. At 3:45pm, severe thunderstorm warnings extended into Simcoe County and then along the west end of Lake Ontario at 4:53pm as the southern end of the line of storms intensified.
The first tornado warning of the day was issued at 5pm, following confirmation of a touchdown near Shelburne, but it was far too late for the communities that were hit the hardest.
The timing of severe thunderstorm warnings, tornado warnings, and tornado touchdowns from May 31st, 1985, courtesy of Leduc, Jacobson, and Greer.
The tracks of thirteen tornadoes from the May 31st, 1985 outbreak with the Grippen Lake Tornado noticeably missing, courtesy of Leduc, Jacobson, and Greer.
Timeline of Tornado Development
The entire outbreak began in Southern Ontario, with a tornado touching down near Rush Cove in the Bruce Peninsula at approximately 3:00pm. It was rated an F2 and was on the ground for approximately 4km. This tornado is interesting because it was much earlier and well removed from the other tornadoes in this outbreak. The remaining 13 tornadoes can actually be grouped into separate families because there were spawned by the same parent supercells.
As the cold front continued to march eastward through Southern Ontario that afternoon, the thunderstorms and the formation of tornadoes travelled along with it. Following the Rush Cove tornado, there was a lull in tornadic activity until shortly after 4pm. Over the course of the following hour, 7 tornadoes spawned, ranging in intensity from an F1 to two F4 tornadoes.
At 4:10pm, an F2 dropped near Hopeville, northwest of Shelburne and it travelled 17km. Then, at 4:15pm, two separate tornadoes developed: an F3 in Alma, to the northwest Fergus, which was on the ground for 33km, and a devastating F4 which touched down near Arthur. This F4 was on the ground for a staggering 115km, setting the record for the longest tracking tornado ever in Canada, and produced estimated maximum wind gusts in excess of 400km/h. It brought significant damage to both Grand Valley and Tottenham, located 50km to the east. Sadly, two people lost their lives in each of these communities.
Damage in Grand Valley following the F4 tornado, courtesy of the Orangeville Banner.
Two minutes later, an F2 touched down near Corbetton, to the northwest of Melancthon. This tornado came from the same supercell thunderstorm as the Hopeville tornado, which had formed only seven minutes prior. This tornado was on the ground for 35km, more than double that of its predecessor.
A little over half an hour later, at 4:50pm, an F2 hit the community of Lisle, to the west of Base Borden, which was also spawned from the same supercell as the Hopeville tornado. It was on the ground for 18km and then seven minutes later, the same storm dropped another tornado just east, an F1 near Essa, which was on the ground for only half a kilometre. The final tornado that this storm produced was the most deadly and destructive of the day, the Barrie F4, which will be discussed in more detail below.
When the Grand Valley-Tottenham tornado finally lifted after being on the ground for well over an hour, its parent supercell went on to produce two more tornadoes: an F1 that touched down north of Uxbridge at 5:40pm and was on the ground for 5km, and another F1 that hit Reaboro, southeast of Lindsay, at 6:05pm and was on the ground for 8km.
While the two main supercells to the north continued to produce multiple tornadoes between 4:00pm and 6:00pm, the thunderstorm behind the Alma tornado didn’t produce another until two hours later, when an F2 touched down east of Highway 35 at 6:15pm, which later tore through Ida along its 9km track. Five minutes later, this storm produced an F3 that travelled 14km along the north shore of Rice Lake and then 15 minutes after that, a final F1 touched down that was on the ground for only 1km near Minto, to the north of Trenton.
This marks 13 total tornadoes from this outbreak and this is what the tally stood at for many years. It wasn’t until around 2010, two and a half decades later, when scientists at Environment Canada were compiling a tornado database, that a missing report from the defunct Kingston Weather Office was found. It detailed damage caused by an F1 tornado which touched down around 8:10pm near Grippen Lake, to the northeast of Kingston. It remains unclear as to why this report was never submitted, but the inclusion of this tornado brings the final number of tornadoes in Southern Ontario on Black Friday to fourteen.
One of the few photos known to exist of the rain-wrapped Barrie Tornado, taken by Gary Crawford from HIghway 11 beside the Drive-In Theatre in Guthrie (edge of Oro). Donated to Instant Weather by Mr. Crawford.
The Barrie F4 Tornado
The Barrie tornado was the strongest of the 14 that touched down on Black Friday, with winds estimated at over 400km/h, making it the second F4 tornado of the day.
The tornado was rain-wrapped as it touched down just outside of the city in a reforestation area, where it snapped many trees and permanently bent even more. It was initially 600m wide, carving a significant path as it approached the edge of Barrie.
As it moved northeastward into the city, the tornado levelled an entire block of homes in the Crawford Street and Patterson Road area, then hit an industrial area known as Molson Park. From there, the tornado turned to travel eastward and crossed Highway 400, terrifying many commuters as their vehicles were pelted by intense winds and debris.
After crossing the Highway, the tornado narrowed to roughly 300m wide and it began devastating the Allendale neighbourhood in the south end of Barrie, destroying homes and uprooting mature trees. Once it ploughed through this built up area, the tornado once again began travelling northeastward. It lastly hit a marina on Kempenfelt Bay before moving out over the water, where it finally dissipated. Given that the end of the tornado’s path of destruction concluded over water, the exact length of its track can not be concretely known, but it is estimated that it was on the ground for approximately 15km.
It was all over in a matter of minutes, but the tornado left scars that would take years to heal.
The initial Draft of the Official survey of the Barrie F4 tornado done by Scott Somerville at Environment Canada, Courtesy of Michael Newark Tornado Digitized Archive by the Northern Tornadoes Project.
Damage & Aftermath
The destruction brought to Barrie was staggering. In a matter of minutes, 155 people were injured, approximately 800 were left homeless, and damage was initially estimated at over $115 million. Sadly, eight residents lost their lives, including four children.
A total of 605 homes were severely damaged and of those, 265 were deemed uninhabitable. In one case, a townhouse complex just east of Highway 400 had its top storey removed and even sections of the main level. Meanwhile, fifteen industrial buildings west of the highway were completely destroyed and many more sustained significant damage. Vehicles were thrown hundreds of metres and 35 sailboats in Kempenfelt Bay completely disappeared.
Damage in Barrie following the F4 tornado, Courtesy of CTV News.
It took well over a year for the residents of Barrie to rebuild following the F4 tornado and this tornado alone ended up causing $130 million ($334 million in 2025 dollars) in damage. This does not even cover the physical and mental damage experienced by the residents, some of which can never be repaired.
The City of Barrie chose to commemorate this tragic event with two plaques: one for those who lost their lives and one for those who helped the community rebuild.
Damage in Barrie following the F4 tornado, Courtesy of CTV News.
Sources:
Harries, K. (Ed.). (1985). Ontario tornado: May 31, 1985. C.F. Boone.
Leduc, M., Jacobson, O., and Greer, B. (1986). The “Black Friday” tornado outbreak in Ontario: A forecaster’s view of the events of May 31, 1985. Chinook, 8(1), 13-18.
Witten, D. E. (1985). May 31, 1985: A deadly tornado outbreak. Weatherwise 38(4), 193-198. https://doi.org/10.1080/00431672.1985.9933314
https://www.cbc.ca/archives/the-tornadoes-that-tore-a-deadly-path-of-destruction-in-ontario-in-1985-1.5575434
https://www.ctvnews.ca/barrie/article/marking-37-years-since-devastating-ontario-tornadoes/
https://www.ctvnews.ca/barrie/article/may-31-1985-the-day-the-sky-unleashed-fury-on-central-ontario/
https://www.theweathernetwork.com/en/news/weather/severe/may-31-1985-outbreak-how-a-lost-14th-tornado-was-found
https://www.theweathernetwork.com/en/news/weather/severe/this-day-in-weather-history-may-31-1985-the-barrie-grandvalley-tottenham-tornadoes
https://www.uwo.ca/ntp/faqs/what_are_canadas_worst_tornadoes.html
https://www.weather.gov/cle/event_19850531_85outbreak
https://www.weather.gov/ctp/TornadoOutbreak_May311985
Special thanks to Dr. David Sills at the Northern Tornadoes Project for his help in answering some inquiries when writing this article.
