The F5s Project

An F5 tornado is a tornado with winds of 200 mph or greater. Tornadoes this powerful are extraordinarily rare. Out of the roughly 52,500 tornadoes that have touched down in the US since 1950, just 71 of them were F5s. That’s 0.13% of the total or about one in every 750 tornadoes. Including the three Canadian tornadoes, 118 are believed to have formed in the past 130 years. That makes for about one every 13-14 months statistically. However, the gaps between F5s have been as long as eight years and short as 20 minutes.

F5s have occurred in 21 states as well as two Canadian provinces. 17 states have had multiple F5s. Kansas leads the pack with an astonishing 15 F5s. They have occurred as far west as Lubbock, Texas (101.5˚W) and as far east as Worcester, Massachusetts (71˚W), as far north as Benson, Saskatchewan (49.45˚N) and as far south as Rocksprings, Texas (30˚N). There appears to be little rhyme or reason to the distribution. Wisconsin has had seven, Minnesota six but Georgia has had none, despite at least 30 F4s (neighboring Alabama has had eight). Pennsylvania and Massachusetts have each had one, but neither of the Carolinas have had any.

Time of year also doesn’t appear to be a factor. 10 out of the 12 months have seen an F5. Curiously, despite being known as the Second Tornado Season in which many devastating F4s have occurred, November has never seen an F5. The other month without an F5 is January (however, the Australian Bulahdelah tornado occurred on New Year’s Day, 1970). April has seen the most F5s with 40, followed closely by May with 39 and June with 25. Outside those three months, the numbers drop off considerably; to seven in March.

While location by itself may not be a factor, terrain is. The F5s, along with essentially all violent tornadoes, stop abruptly at the base of the Rockies. The Lubbock tornado, as mentioned above, is the westernmost F5 in the historical record, though an F5 that struck farmland near Oshkosh, Nebraska (102W) in 1938 may have been slightly farther west. The controversial Edmonton tornado in Alberta in 1987 was much further west (113.3˚W), however, Canada’s plains extend much farther west than their American counterpart. The furthest west an F4 has been reported was in the Teton National Forest of Wyoming south of Yellowstone National Park in 1987. Colorado has not recorded an F4 in 66 years and neither Montana nor New Mexico has ever had a violent tornado.

The Bulahdelah tornado in New South Wales, Australia is the only tornado outside the US and Canada included on this list based on specific damage reports I turned up in my research. Other possible international F5s include storms from France in 1967 and Russia in 1984. Other less convincing reports of F5 damage have come from Poland and the Netherlands.

The most that have ever formed in a single year are the unbelievable seven that formed in as many hours during the Super Outbreak of April 3, 1974. 1953 is a close second with six. Eight days have seen more than one F5, seven of them coming after 1950. Only with the Super Outbreak’s ridiculous seven F5s have there been more than four on a single day. April 27, 2011 was the only other time there’s been more than two. That’s just one of many statistics that show just how incredible the events of April 3, 1974 were.

No one town has ever been directly impacted by two officially rated F5s, however three towns have come very close. In 1977, an F5 tore through the Smithfield neighborhood of Birmingham, Alabama, killing 22. Then in 1998, another F5 obliterated the village of Oak Grove just ten miles to the west and continued into the southern portions of the city, killing 32 people.

On March 13, 1990, two F5’s formed from the same supercell in south-central Kansas. The first struck Hesston and lifted just west of Goessel. The second formed just south of Goessel and caused heavy damage in the town.

The infamous town of Murphysboro, Illinois is associated with two different F5s; the legendary “Tri-State Tornado” of March 18, 1925 and the tornado of December 18, 1957. However, the 1957 storm actually struck further north near the village of Sunfield. An F4 did in fact strike Murphysboro that day, possibly leading to confusion.

The town of Tanner in Limestone County, Alabama was obliterated by two powerful tornadoes during the Super Outbreak of April 3, 1974. The first was rated F5, but the second is officially a “high-end” F4. Some official sources list both tornadoes as F5s. The damage caused by the two tornadoes was difficult to distinguish. It is quite possible that this small town was struck by two F5s within 45 minutes of each other. Another example of how unprecedented the Super Outbreak truly was. In an eerie coincidence, 37 years later, the massive Hackleburg tornado produced near-EF5 damage in the Tanner area.

On May 20, 2013, Moore, Oklahoma became the first town to take a direct hit from two officially-rated F5/EF5 tornadoes. The first came on May 3, 1999 and is believed to be the strongest tornado ever reliably measured. The area around the nearby town of El Reno was hit by two EF5 tornadoes within the span of two years in 2011 and 2013, however El Reno itself wasn’t hit by either tornado, the first passing just to the north and the other passing to the south. The second tornado was the widest ever recorded, at 2.6 miles.

Only six times has an F5 struck the same state in consecutive years. Kansas has done it twice: 1895-1896 and 1990-1991. The other four are Iowa in 1894-1895, Wisconsin in 1898-1899, Texas in 1953-1954 and Nebraska in 1964-1965. Two of the three post-1950 instances were completed by tornadoes not officially classified as F5s at the time but are strongly suspected of having reached F5 intensity by experts and historians.

Mississippi has the unfortunate distinction of being the only state to have been struck by both an F5 tornado (six of them) and a Category 5 hurricane (Camille). The Inverness tornado of 1971 came just a year and a half after Camille. Hurricane Carla nearly did it to Texas in 1961, but weakened just before landfall. Beulah of 1967 was another near miss, striking northeast Mexico just 20 miles south of the Texas border. Texas has had 13 F5s in recorded history, the last striking Jarrell in 1997. Florida is the only other US state to have been struck by a Category 5 hurricane (two of them). The strongest tornado in Florida history was rated F4. Also, an F5 and an Atlantic Category 5 have formed in the same year just 15 times in at least the past 130 years, most recently in 2007.

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