Published: 8:49 PM GMT on May 22, 2013
F-5/EF-5’s and The World’s Deadliest Tornadoes
The recent catastrophic EF-5 tornado in Oklahoma has prompted me to revisit a blog I posted in April 2011 (ironically that blog was posted just two weeks prior to the deadly tornado outbreak on April 27-28 of that year). This blog updates the lists of all known F-5 and EF-5 tornadoes and other statistics concerning the deadliest tornadoes on record in U.S. and world history.
The violent EF-5 tornado bearing down on Moore, Oklahoma on May 21st. This is the 2nd time the town has endured a devastating direct strike by an EF-5 tornado, the previous occurrence being on May 3, 1999. 11 people died in the town during that event. Clip from video shot by a helicopter working with KWTV Sky News channel 9 out of Oklahoma City.
The Moore storm has officially been rated as an EF-5 tornado, making it the first such since another Oklahoma tornado that struck on May 24, 2011. To view the May 20th Oklahoma tornado in an historical context so far storms in Moore and the state see this excellent ‘fact sheet’ put together by the NWS-Norman, Oklahoma office.
The United States and Canada are the only countries in the world to have verified reports of the most violent tornadoes: those with a classification of F-5 or EF-5 (wind speeds estimated to be in excess of 200mph/320kph and measured as high as 318mph/512kph on the new Fujita Scale). See for details about the Fujita and Enhanced Fujita Scales and the differences between the two.
Since 1900 there have only been a total of 91 such storms, all but one in the United States. In all but 10 cases these storms resulted in fatalities. Below is a list of all F-5/EF-5 known tornadoes, their locations, and fatalities associated with each case. All but 6 of these have occurred between March-June. The month of April has accounted for 31 of all known F-5/EF-5’s (the most for any single month) and May with 29. The only months to never have reported an F-5/EF-5 are January, September, and November.
List of all F-5 and EF-5 U.S. and Canada tornadoes since 1900
SOURCES of F-5 list: Thomas Grazulis through 1949 and NWS since 1950. There are five cases since 1950 that Grazulis rates as F-5 and the NWS rates as F-4. I have indicated those in dispute with Grazulis’s name next to the event. Also, there seems to be confusion over whether or not both of the two tornadoes that struck Tanner, Alabama on April 3, 1974 were F-5s. Some sources (including the NWS I believe) rate the second twister at just a F-4.
For a list of specific towns struck by F-5 and EF-5 tornadoes and other candidate tornadoes of this strength from the U.S and around the world (including pre-1900 events) see this Wikipedia site.
The reason the heart of the North American continent bears the brunt of these most powerful of twisters lies with its unique topography. Only in North America does a solid land mass stretch from the sub-tropics to the arctic with no mountain barriers to inhibit the mixture of air masses originating from these two regions.
The deadliest single tornadoes and tornado outbreaks in U.S. history
Most of you probably already know that the ‘single’ deadliest tornado in U.S. history was the famous ‘Tri-state’ twister of March 25, 1925 when 695 died in Missouri, Illinois, and Indiana when a F-5 mile-wide monster carved a course some 219 miles through the three states. However, modern research suggests that this may well have been a series (or at least two) tornadoes developing from a single super cell traversing the area. Eight other strong (F-2 or stronger) tornadoes killed an additional 52 people in Alabama, Tennessee, and Kentucky over the course of the day bringing the total killed to 747 and making this also the deadliest tornado outbreak in American history.
The recent Moore, Oklahoma tornado event was not the first time early reports of the number of fatalities proved inaccurate. Following the Tri-state tornado of March 25, 1925 the Chicago Herald-Examiner reported 1,000 deaths. In fact, the total was 695 including 234 in Murphysboro, Indiana alone which remains the 3rd greatest single-city death toll in U.S. history (Natchez, Mississippi is 1st and St. Louis 2nd). Front page from the Chicago Herald-Examiner Archives.
The 2nd deadliest single tornado was that which struck Natchez, Mississippi on May 7, 1840 killing 317, many of the fatalities being along the town’s waterfront when the twister traversed the Mississippi River. This remains the deadliest single-city tornado in U.S. history. The 2nd deadliest tornado outbreak (as opposed to single tornado) was that of April 5-6, 1936 when 454 were killed across the Southeast from Arkansas to South Carolina. Tupelo, Mississippi was the worst affected where 216 were killed by a single tornado (a young Elvis Presley lived there at the time).
Below are tables listing the 15 deadliest U.S. tornado outbreaks and 15 deadliest single tornadoes in U.S. history. Some of these figures are, to some degree, disputable and simply represent the best available information to date:
* There were 348 storm-related fatalities during this event (not 342 as indicated on the chart) but only 324 of these were directly tornado-related. However, it is likely that some of the fatalities in the other tornadoes listed were also not directly tornado related.
These are the only known tornadoes to have killed 100 people or more in the U.S. P.S. The last site on the table above should read 'Shinnston, WW'. Source: Storm Prediction Center.
A F-5 tornado completely swept away the town of Glazier, Texas on April 9, 1947. The same tornado killed 181 in Woodward, Oklahoma (see table above) and so ranks as the 6th deadliest tornado in U.S. history. Like the Tri-state tornado, there is suspicion that this event may actually have been composed of a family of tornadoes that developed within a single super cell. Photo courtesy of the ‘Amarillo Globe-News’.
Deadliest tornadoes in Canada
Map of the areas in Canada where tornadoes are most likely to occur.
Environment Canada has concluded that the tornado that formed near Elie, Manitoba on June 22, 2007 was of EF-5 strength making it the only such storm of this violent nature verified to have occurred outside of the United States. Canada’s deadliest tornado event was that of June 30, 1912 when 28 were killed in the city of Regina, Saskatchewan. More recently, 27 died in and around Edmonton, Alberta on July 31, 1987 when a F-4 slammed the city.
The second deadliest tornado in Canadian history bears down on Edmonton, Alberta on July 31, 1987. Twenty-seven lives were lost. Photo by Robert Carlton, University of Alberta.
Deadliest Tornadoes from around the world
This map illustrates regions of the world that experience tornado development. Map from ‘Extreme Weather: A Guide and Record Book’.
Below is a summary of other countries aside from the U.S. and Canada that have also experienced strong and deadly tornadoes (EF2-4 strength but, to date, no EF-5s):
Bangladesh has suffered the deadliest tornadoes on record and several of these have been estimated to be in the F-4 category of strength. The reason Bangladesh receives violent tornadoes is because during the beginning of the wet monsoon season (usually April and May) cold dry air spilling south over the Himalayan massif encounters deep tropical moisture streaming north from the Bay of Bengal. The ensuing violent thunderstorms produce not only tornadoes but also some of the largest hail ever observed (the heaviest single hailstone ever measured on earth weighed in at 2.25 pounds on April 14, 1986 during a storm in the Gopalanj District—unfortunately, the diameter of the stone was not noted).
A synoptic map illustrates the location of a tornado that occurred in Bangladesh on May 4, 2003 (where the red ‘T’ is on the map). The twister formed along a trough boundary between a moist SW monsoon flow from the Bay of Bengal and cooler dry air spilling southward from the Tibetan Plateau while a dry line moved in from the west. These are the same weather elements that often contribute to the formation of violent tornadoes in the U.S..
The deadliest tornado in Bangladesh, and thus world, history (at least in modern records) was that which occurred on April 26, 1989. At least 1,300 deaths were reported from flattened villages in a region just north of the city of Dacca. On May 13, 1995 another 700 lives were lost in the city of Tangail as the result of a violent tornado. Four other tornado events have killed 500 or more people in Bangladesh since 1964 (on April 11, 1964, April 14, 1969, April 17, 1973, and April 1, 1977). This list provides more details about these events.
Although tornadoes are relatively rare in South America, Paraguay, Brazil, and Argentina have recorded some violent twisters that may have reached the F3-4 level of intensity as was the case on January 10, 1973 when 50-70 people were killed in the town of San Justo, Santa Fe State northwest of Buenos Aires, Argentina. South America's deadliest tornado event was that of September 20, 1926 when a violent twister struck Encarnacion, Paraguay killing "over 300" according to press reports at the time. This may rank as one of the world's deadliest tornado events depending on just how many actually died as a result of the storm.
Tornado expert Thomas Grazulis has speculated that Russia might receive the largest absolute number of tornadoes each year, following the United States, due to its vast size and “potential for small tornadoes”. Violent tornadoes, however, have been known to occur as was the case on June 9, 1984 when as many as 400 people were reported killed during an outbreak in a region 150-200 miles north of Moscow.
Violent tornadoes are extremely rare anywhere in Western Europe although many weak ones occur every year. The deadliest tornado in Western Europe’s history struck three textile and paper mills near Monville, France on August 19, 1845 killing at least 70 people. Sketchy reports of waterspouts coming ashore in the Mediterranean claim fatalities of 500 in Sicily in December 1851 and 600 killed in the Grand Harbour at Valetta, Malta on September 2, 1551. There seems to be few details concerning these events and uncertainty as to the actual dates of occurrence.
The only country in Africa to occasionally report a violent tornado is South Africa where powerful thunderstorms often erupt during the summer months of November through February. The deadliest tornado outbreak in the nation’s history was that of November 30-December 2, 1952 when 31 people were killed in the towns of Albertynesville and Paynesville near Johannesburg.
In Japan about 20 tornadoes, or tatsumaki (dragon whirls), are reported annually. These are most often associated with super cell thunderstorms that develop along the Pacific Coastline during the summer months. Weaker winter tornadoes (similar to those that affect the U.S. West Coast during winter storms) are also known to form. However, the strongest tornado in Japanese history was one of these winter ones which hit the coastal city of Mobara (20 miles southeast of Tokyo) on December 1, 1990. It was rated as a F-4 and destroyed over 1000 buildings and injured 100 people. There were no fatalities. The deadliest tornado in modern Japanese records killed 16 at an elementary school in Miyazaki city on September 26, 1881.
AUSTRALIA and NEW ZEALAND
Australia reports about 20-25 tornadoes a year, the same number as New Zealand, and in both cases they are usually relatively weak. Occasionally they become strong enough to warrant an EF-3 rating. New Zealand has had two tornado events resulting in the deaths of 3 people. The first event was that of August 25, 1948 which struck the towns of Frankton and Hamilton. It was rated as a F-2 in intensity. The second and more recent event was that of December 6, 2012 that swept through the Auckland suburbs of Hobsonville and Whenuapai. It was also rated as an EF-2.
Australia’s deadliest twister was that of August 14, 1971 when 3 were killed at Kin Kin (a small community between Gympie and Noosa) in southern Queensland.
The Bucca, Queensland tornado of November 29, 1992 was the strongest tornado (F-4) ever reported in Australia. There were no fatalities. Photo courtesy of Emergency Management Australia.
The Top Ten Deadliest Tornado Outbreaks in the World Since 1900
The great U.S. tornado outbreak of April 27-28, 2011 would tie for 11th place on this list with its 324 tornado-related fatalities but be in 10th place if the 348 death toll figure is used. See table and discussion earlier in blog on deadliest U.S. tornadoes.
BEST REFERERNCE: The single best reference work about tornadoes and tornado history is Thomas P. Grazulis’s masterpiece Significant Tornadoes: 1680-1991. A supplement to this was published bringing the data up to 1995. Unfortunately, no further editions have been published to cover the past 17 years although his web site has done so.
Christopher C. Burt