Disagreements on the intensity of tornadoes

Since the late 18th century, meteorologists and engineers have worked to assess the intensity of tornadoes, typically through the work of a tornado damage survey or a scientific case study. This work has led to the creation of the Fujita scale (F-scale) in 1971 and the TORRO scale in 1975. However, the original Fujita scale lacked the incorporation of diverse empirical damage to estimate wind speeds, such as construction quality; to address this, the Enhanced Fujita scale (EF-scale) was created in 2007, followed by the International Fujita scale (IF-scale) in 2023. Despite these efforts to help assess the strength of tornadoes, engineers, scientists and academics have disagreed with each other on how strong various tornadoes were. This is a list of notable disagreements on the intensity of a particular tornado.
The Fujita scale was the first method to systematically rate tornadoes based on damage assessment. It linked damage descriptions—like felled trees or destroyed houses—to a bracket of wind speeds that would have been necessary to cause the damage, assigning each a rating from F0 to F5. This approach to rating tornadoes and concluding their probable wind speeds was revolutionary and was replicated and adapted into the various scales used today. These evaluations are significantly affected by the subjectivity of individual survey teams, however; slight differences in interpretation can lead to markedly different ratings even for the same event. Furthermore, separate damage scales used in different countries have a bias towards certain construction types. The Enhanced Fujita scale, for instance, was constructed based on the United States' construction standards, whereas the TORRO scale implicitly reflects British construction standards and ultimately ties back to the Beaufort scale.
It is often difficult to distinguish tornadoes in the upper echelons of the Fujita scale as minute details must be analyzed in order to provide an accurate rating. Conversely, tornadoes which leave behind little to no damage can not be accurately represented using damage assessment methods. Tornadoes that happened farther in the past or in regions outside of more tornado-prepared areas will have similar difficulty in receiving an accurate rating due to a dearth of information. The situation is further muddled by the fact that these scales incorporate different types of data, leading to differing ratings based on which scale is used. For example, the International Fujita scale uniquely uses measured wind speeds via Doppler weather radar alongside damage assessment techniques. This variation in the interpretation of damage and in the methodology by which to categorize it often causes engineers and scientists alike to disagree on the strength of tornadoes.
On July 20, 1931, a violent tornado struck the city of Lublin in Poland. The damage from the tornado was rated F4 on the Fujita scale by the European Severe Storms Laboratory. The Polish Weather Service estimated that the tornado had winds between 246 to 324 mph (396 to 521 km/h). This mean it was potentially at F5 intensity, as F5 tornadoes begin with winds at 261 mph (420 km/h). Staff of the University of Warsaw and Adam Mickiewicz University in Poland as well as the National Oceanic and Atmospheric Administration in the United States also believe the tornado may have been F5 intensity.
On April 2, 1957, an intense tornado struck the city of Dallas in Texas. In 1958, E. Segner, with the American Meteorological Society and American Society of Civil Engineers, conducted a case study on the tornado, where it was estimated the tornado had winds of at least 302 mph (486 km/h), based on the obliteration of a large billboard. Following the creation of the Fujita scale in 1971, the National Weather Service office in Fort Worth, Texas, rated the worst of the damage F3, with winds of 158–206 miles per hour (254–332 km/h).
On April 11, 1965, a tornado outbreak struck much of the Ohio Valley. Multiple tornadoes during the outbreak would have disputed ratings.
An F4 tornado struck the cities of Elkhart and Goshen, as well as the community of Dunlap in Indiana. The tornado completely destroyed the Sunnyside subdivision and the Kingston Heights subdivision in Dunlap. Following the creation of the Fujita scale in 1971, the National Weather Service office in Northern Indiana rated the worst of the damage F5. However, after further analysis, this rating was officially downgraded to F4. Tornado expert Thomas P. Grazulis rated the tornado F5 in 1993. In 2000, the National Oceanic and Atmospheric Administration along with the Nuclear Regulatory Commission rated the tornado F5.
Another F4 tornado struck the towns of Lebanon and Sheridan in Indiana. Following the creation of the Fujita scale in 1971, the National Weather Service office in Northern Indiana rated the worst of the damage near Lebanon and Sheridan F4, stating the tornado "may have been an F5". In 2000, the National Oceanic and Atmospheric Administration along with the Nuclear Regulatory Commission rated the tornado F5.
Yet another violent tornado struck the towns of Pittsfield, Grafton, LaGrange, and Strongsville in Ohio. Homes were cleanly swept away in Strongsville and Pittsfield, and Pittsfield was completely destroyed. Only a concrete war monument remained standing in Pittsfield, where homes "vanished." Following the creation of the Fujita scale in 1971, the National Weather Service office in Northern Indiana rated the worst of the damage F4. Tornado expert Thomas P. Grazulis rated the tornado F5 in 1993. In 2000, the National Oceanic and Atmospheric Administration along with the Nuclear Regulatory Commission rated the tornado F5.
On May 11, 1970, a powerful multi-vortex tornado struck the city of Lubbock, Texas. The tornado, in its time the costliest tornado in U.S. history, causing an estimated $250 million in damage (equivalent to $2.02 billion in 2024), damaging nearly 9,000 homes and inflicting widespread damage to businesses, high-rise buildings, and public infrastructure. The tornado's damage was surveyed by meteorologist Ted Fujita in what researcher Thomas P. Grazulis described as "the most detailed mapping ever done, up to that time, of the path of a single tornado." Originally, the most severe damage was assigned a preliminary F6 rating on the Fujita scale, making it one of only two tornadoes to receive the rating, alongside the 1974 Xenia tornado. Later, it was downgraded to an F5 rating. The extremity of the damage and the force required to displace heavy objects as much as was observed indicated that winds produced by vortices within the tornado may have exceeded 290 mph (470 km/h).
On April 27, 1971, a violent tornado struck parts of Russell and Pulaski County, Kentucky, in particular, the community of Gosser Ridge. In Gosser Ridge, the tornado destroyed a farmhouse, killing two people and destroying nearly every building. Several other homes were destroyed and multiple injuries occurred in Gosser Ridge. In Gosser Ridge, "questionable F5" damage occurred, which led the National Oceanic and Atmospheric Administration and the Nuclear Regulatory Commission to rate the tornado F5 on the Fujita scale. In August 2000, the tornado was still rated F5; however, it was later downgraded to F4.
On April 3, 1974, one of the most destructive tornado outbreaks on record would affect much of the United States. This included a violent tornado struck the towns of Xenia and Wilberforce in Ohio. Immediately following the tornado, Dr. Ted Fujita and a team of colleagues from the University of Chicago, University of Oklahoma, and National Severe Storms Laboratory, undertook a 10-month study of the 1974 Super Outbreak. Along with discovering new knowledge about tornadoes, such as downbursts and microbursts, and assessing damage to surrounding structures, the Xenia tornado was determined to be the worst out of 148 storms. Fujita initially assigned a preliminary rating of F6 intensity ± 1 scale. This rating was later officially downgraded by the National Weather Service office in Cincinnati, Ohio (now located in Wilmington, Ohio), which rated the worst of the damage in Xenia F5.
Another violent tornado struck several towns in Lincoln County, Franklin County, and Coffee County in Tennessee. The worst of the damage in Franklin County was rated F5 by the National Weather Service, however, in March 2012, the National Weather Service stated they could not confirm if the United States Weather Bureau ever conducted a damage survey after the tornado. Professor Ted Fujita and several of his graduate students did conduct a damage survey, where they "were unable to locate the reference to 'incredible damage' that results from an F5" rating. After their survey and analysis, Fujita and his students sent a letter to the Storm Prediction Center, recommending the tornado be downgraded to an F4 rating. Following this letter, the National Weather Service downgraded the tornado to an F4 rating.
On July 16, 1979, an intense tornado struck Cheyenne, Wyoming. The worst of damage was rated F3 by the National Weather Service office in Cheyenne. However, in May 1980, William T. Parker and Richard D. Hickey, meteorologists at the National Weather Service office in Cheyenne published a case study on the tornado. In the study, they stated "F4 damage was found in a portion of the Buffalo Ridge housing area where large two-story, single family houses were reduced to foundations surrounded and covered by debris." The researchers also stated the path width of the F4 damage area was 220 metres (240 yd).
On June 9, 1984, an unusually significant tornado outbreak took place that saw a violent tornado strike the cities of Ivanovo and Lunyovo in the eastern Soviet Union (now Russia). One particularly devastating multiple vortex tornado touched down south of Ivanovo, travelling north-northeast as it snapped swaths of birch, spruce, and pine trees. The tornado tossed aside a large crane which weighed 320,000 kilograms (710,000 pounds) and lofted an elevated water tank that weighed 50,000 kilograms (110,000 pounds) a distance of over 200 metres (0.12 mi). The northern suburbs of Ivanovo, consisting of many wooden summer homes, were flattened, with other structures being completely obliterated or swept away to their foundations. Numerous trees were denuded, debarked, or uprooted. Cars at this location were rendered unrecognizable. Researchers disagree on the intensity of the tornado, with some estimating it had an F4 rating and others believing it deserved an F5 rating. In fact, the Ivanovo tornado was originally classified as an F5 before the ESSL recategorized it as an F4 in 2018.
On June 1, 1990, a large, violent, multi-vortex tornado struck rural parts of Pecos County, Texas, including the ranching community of Bakersfield Valley. A well-engineered adobe brick home was destroyed by the tornado at F4 intensity. A 300-foot section of asphalt was scoured from a road, as well as nearby suction marks and an 8 mile long by half mile wide swath of scoured vegetation were noted by the surveyors. This damage was also rated as F4. After decreasing in intensity slightly and causing two fatalities in pickup trucks, the tornado restrengthened and struck the Yates Oil Field, where 57 oil pumps and other equipment were damaged or destroyed. Most notably at this location, three full 500-barrel oil tanks, weighing approximately 70 tons each, were broken free from a tank battery and rolled for more than 3 miles across a field and pushed up a hill. Damage at the oil field earned an F4 rating. Surveyors noted that the tornado produced damage not seen in the Saragosa tornado three years prior, such as the asphalt scouring and the extensive vegetation scouring. They also suspected that the Bakersfield Valley tornado was stronger than the Saragosa tornado at times, but the evidence was insufficiently conclusive to warrant an F5 rating.
On June 8, 1995, an extremely severe and localized outbreak of tornadoes occurred in the Texas Panhandle. Four of these tornadoes' ratings would be called in to question—three were officially rated F4 and one was rated F2—with many believing that the event was significantly underrated. A violent stovepipe tornado struck the city of Pampa, Texas after touching down to its southwest. Its short path length and lack of damage to structures limited its rating. Per Thomas P. Grazulis, the F4 rating it was given was based on the movement of industrial equipment, as the tornado had weakened significantly by the time it entered more populated areas. Grazulis used photogrammetry to conclude that at about 100 feet above ground level, the tornado had wind speeds in the 200–250 miles per hour, not counting a powerful vertical wind component. Grazulis later discussed the Pampa event in F5-F6 Tornadoes and declared "In my opinion, if there ever was an F6 tornado caught on video, it was the Pampa, Texas tornado of 1995". The same supercell responsible for the Pampa tornado cycled and produced another significant tornado near Hoover, Texas, which was officially rated F2. Narrowly missing the Rufe Jordan Unit prison, this tornado displayed significant strength by stripping asphalt from the local highways. Storm chasers who saw the event concur that this tornado is underrated, with Martin Lisius rating it as an F5 tornado.
An hour after the Hoover tornado lifted, a second significant supercell formed near Clarendon, Texas. After producing three F2 tornadoes, the storm cycled and produced a violent tornado near the community of Kellerville, tracking northeast. Significant ground scouring was documented along its unusually sinusoidal damage track, and winds exceeding 110 m/s (246 mph, 396 km/h) were recorded by Doppler radar. Asphalt was stripped from roads and several structures were destroyed, including some swept away from their foundations. The extraordinary damage and high recorded wind speeds leads researchers and storm chasers alike to attest that the Kellerville tornado had attained F5 strength. The same supercell responsible for the Kellerville tornado cycled and formed a violent tornado to the west of Allison, Texas. The tornado initially moved to the northeast at around 60 miles per hour with a maximum width of 1.25 miles before slowing significantly, turning to the west, and occluding similar to the tornado before it. The tornado avoided the town but killed hundreds of livestock in Wheeler County. Despite every spotter report listing the tornado as an F5, the National Weather Service rated it an F4 due to a lack of structural interactions.
On April 28, 2002, a violent and fast-moving tornado struck the town of La Plata, Maryland. The tornado was initially rated F5 by the National Weather Service office in Baltimore/Washington, but it was downgraded in a secondary damage survey. For a small period of time, this made it the easternmost F5 tornado in the United States. This preliminary F5 rating, partly due to damage to a brick building in downtown La Plata, was lowered to F4 after the damage assessment team determined that some of the damage was due to flying debris from a lumber company nearby. Damage to houses initially rated F5 were lowered when engineer Timothy Marshall surveyed and determined these homes were not properly anchored, causing them to be swept off their foundations by lesser winds. While impressive, team members agreed that the tornado damage was not as intense as other F5 rated tornadoes such as the ones that struck Plainfield, Jarrell, Bridge Creek-Moore, or Andover. Many of the destroyed buildings or "slider homes" were only rated F1 to F3, with surveyors having to depend some ratings solely on the severity of the surrounding damage. This includes the toppled steel water tower in La Plata, which "was impressive but occurred in an area of F1 damage". This event showcased some of the prime issues with using the Fujita scale and is largely responsible for the how tornadoes are surveyed today.
On June 22, 2007, a small but powerful tornado struck the southwestern part of Elie, Manitoba. The next day, a preliminary damage assessment by Environment Canada concluded that out of the four houses destroyed by the tornado, the most damaged house received an F4 rating. While they did initially consider rating the tornado as an F5, the lack of any previous F5-rated tornadoes in Canada resulted in the lower rating. Additionally, the investigators were concerned about the scrutiny they would receive from the media and meteorological community if they rated the tornado an F5, and how they could not confirm whether the extreme damage was a result of the tornado's slow motion. In September 2007, Environment Canada officially upgraded the tornado's rating from F4 to F5 based on video evidence and a second damage survey. The videos showed that not only did the tornado remain over each house for no longer than 30 seconds, but also that it showed how exactly the well-built homes were torn their foundations.
In 2008 at the American Meteorological Society's 24th Conference on Severe Local Storms, Patrick J. McCarthy, along with D. Carlsen and J. Slipec, submitted a paper for and hosted a presentation on the Elie tornado. At the conference, it was presented that some of the damage did point to an F5 rating, however, the survey team was concerned the tornado was weaker than F5 strength, and only caused the extreme damage due to moving slowly, where it could have "relentlessly pounded the houses into a higher level of destruction". After further investigation using video evidence captured by people watching the tornado, the surveyors determined that "the structural failures were quick. The structural assessments indicated that the homes were well-built and generally well-secured. In particular, one of the destroyed homes met all of the requirements for the highest damage rating." The team also noted that the damage would have qualified for an EF5 rating on the Enhanced Fujita scale, which was in use in the United States at the time.
On April 27, 2011, the most large-scale tornado outbreak would devastate much of the southern United States, with 5 tornadoes having a disputed rating.
A fast-moving and multi-vortex tornado struck parts of Chickasaw and Monroe counties in Mississippi. The predecessor to the devastating Smithville tornado, it mostly traveled over rural land and hit relatively few structures. However, numerous trees were debarked and denuded and the homes it encountered were significantly damaged or swept from their foundations. Grass scouring was consistently recorded with several inches of topsoil scoured away on occasion. A man and his truck driving on Highway 45 were picked up by the tornado, tumbling through the air for around 90 seconds before impacting the ground 1.7 miles (2.7 km) away on Chapel Grove Road, unfortunately killing him. Around this time, a well-built and well-anchored brick home was disintegrated by the tornado, sweeping its foundation clean and spraying its debris to the northeast, indicative that this tornado was very violent before sharply weakening and lifting near northern Amory, Mississippi. Due to a lack of manpower in more rural regions after the outbreak, survey teams were unable to reach the damage in the community of Chapel Grove, and only an EF3 rating could be given. Many experts agree that the incredible damage recorded near the community would have warranted at least an EF4, if not an EF5 rating, if the survey teams could have assessed the damage in time.
Another violent and fast-moving tornado struck several towns in eastern Mississippi, including the town of Philadelphia, Mississippi. The National Weather Service office in Jackson, Mississippi, rated the worst of the damage EF5 with winds of at least 205 miles per hour (330 km/h). In July 2014, sixteen researchers from the National Weather Service, the University of Alabama in Huntsville, the Universities Space Research Association, and the University of Oklahoma, published a case study on the 2011 Super Outbreak. In the study, the authors say the EF5 rating came from "stripped clumps of grass out by the roots, up to depths of 0.5 metres (0.55 yd), in addition to large sections of pavement stripped away from a roadway". This were noted to be "extreme damage" caused by tornado which was a non-standard damage indicator on the Enhanced Fujita scale.
In October 2024, mechanical engineer Ethan Moriarty analyzed the tornado's damage in comparison to non-EF5 tornadoes. Moriarty noted that based on justifications from various National Weather Service offices on other tornadoes, the EF5 rating for the tornado could be "nullified". On January 23, 2025, Anthony W. Lyza with the National Severe Storms Laboratory along with Harold E. Brooks and Makenzie J. Kroca with the University of Oklahoma’s School of Meteorology published a paper to the American Meteorological Society regarding the EF5 drought. In the paper, the researchers stated the justification for the EF5 rating was a single frame home that was swept away, "within the context of extreme ground scouring (2 feet (0.61 m)-deep trench) and a mobile home tossed about 300 yards (270 m)." The researchers stated this reasoning was directly given to them by the National Weather Service Jackson, Mississippi office and from Alan Gerard with the National Severe Storms Laboratory, through personal communication in 2024.
Another large and long-lived tornado struck several towns in rural northern Alabama before tearing through the northern suburbs of Huntsville; in particular the towns of Hackleburg, Phil Campbell, and Tanner in Alabama. The National Weather Service offices in Birmingham and Huntsville, Alabama, rated the worst of the damage caused by the tornado EF5 with winds estimated to be at least 210 miles per hour (340 km/h). Nearly two-dozen locations along the tornado's track were rated EF5.
In October 2024, mechanical engineer Ethan Moriarty analyzed the tornado's damage in comparison to non-EF5 tornadoes. Moriarty noted that based on justifications from various National Weather Service offices on other tornadoes, the EF5 rating for the Hackleburg–Phil Campbell tornado could be "nullified". On January 23, 2025, Anthony W. Lyza with the National Severe Storms Laboratory along with Harold E. Brooks and Makenzie J. Kroca with the University of Oklahoma’s School of Meteorology published a paper to the American Meteorological Society regarding the EF5 drought. In the paper, the researchers stated the justification for the EF5 rating was numerous homes that were swept away, however, only a single home was "bolted to its foundation". The researchers also noted that in Hackleburg, the National Weather Service office in Birmingham, Alabama, used "the tossing of vehicles 150–200 yards (140–180 m) and the wind rowing of debris" as contextual reasons to apply the EF5 rating. The researchers went on to state how "only one home was explicitly noted to have actually been anchored to its foundation", and the only location to warrant an EF5 rating.
Another violent multi-vortex tornado destroyed portions of Tuscaloosa and Birmingham, Alabama, as well as smaller communities and rural areas between the two cities. The National Weather Service office in Birmingham, Alabama rated the worst of the damage caused by the tornado EF4 with winds of at least 190 miles per hour (310 km/h).
The Chastain Manor Apartments, which were nailed, rather than bolted to their foundations, were completely destroyed and partially swept away by the tornado in the outskirts of Tuscaloosa. A well-anchored clubhouse on the property was mostly swept away and its remains were scattered into a pond, even though the structure had lacked interior walls. A nearby manhole cover was removed from its drain and thrown into a ravine. The suburbs of Concord, Pleasant Grove, and McDonald Chapel, along with residential areas in northern Birmingham itself, were also devastated by the tornado. Extensive wind-rowing of debris was noted in Concord and Pleasant Grove, numerous trees were debarked, and some homes were swept away, although much of the debris remained next to the foundations and was not scattered, and most vehicles were not moved more than 15 yards (14 m). As the tornado moved across a coal yard in this area, a 35.8-tonne (78,925 lb) coal car was thrown 391 ft (119 m) through the air.
The final rating of this tornado was a source of controversy, as some survey teams concluded EF5 damage, while others did not. The structures that were swept away by this tornado were either improperly anchored, lacked interior walls, or were surrounded by contextual damage not consistent with winds exceeding 200 mph (320 km/h), and as a result an EF5 rating could not be applied. Therefore, it was given a final rating of high-end EF4, with winds estimated at 190 mph (310 km/h). President Barack and First Lady Michelle Obama visited Tuscaloosa on April 29, taking a ground tour of some of the affected areas. Obama was quoted as saying that he had "never seen devastation like this."
In October 2024, mechanical engineer Ethan Moriarty analyzed the tornado's damage in comparison to non-EF5 tornadoes. Moriarty noted that based on justifications from various National Weather Service offices on other tornadoes, the EF5 rating for the Rainsville tornado could be "nullified". On January 23, 2025, Anthony W. Lyza with the National Severe Storms Laboratory along with Harold E. Brooks and Makenzie J. Kroca with the University of Oklahoma’s School of Meteorology published a paper to the American Meteorological Society, where they stated the tornado in Tuscaloosa was an "EF5 candidate". It was also explained that the EF5 starting wind speed should be 190 miles per hour (310 km/h) instead of 201 miles per hour (323 km/h).
Another large and violent tornado struck areas of DeKalb County, Alabama and Dade County, Georgia, particularly around the communities of Shiloh, Rainsville, and Henagar. The National Weather Service office in Huntsville, Alabama, rated the worst of the damage EF5 with winds of at least >200 miles per hour (320 km/h), with numerous locations being rated EF5. The National Weather Service rated a "corridor from CR 515 through a neighborhood along County Road 441" as "near EF-5". In that area, numerous one- and two-story homes were leveled to their foundation with debris scattered, cars were thrown large distances, and some sidewalk pavement was pulled up out of the ground by the tornado. "However, some of the homes in this area appeared to be pushed off their foundation initially with limited anchorage. Thus, the damage was deemed high end EF-4 in this area."
On January 23, 2025, Anthony W. Lyza with the National Severe Storms Laboratory along with Harold E. Brooks and Makenzie J. Kroca with the University of Oklahoma’s School of Meteorology published a paper to the American Meteorological Society regarding the EF5 drought. In the paper, the researchers stated the justification for the EF5 rating was a single location where a large, two-story brick home that was "blown off of its foundation, with several anchors pulled out of the ground and a 800 pounds (360 kg), anchored safe found 600 feet (180 m) away with its door ripped off."
On May 22, 2011, a large and devastating tornado struck the city of Joplin, Missouri. The worst of the damage caused by the tornado was rated EF5 by the National Weather Service Springfield, Missouri (NWS Springfield), four days after the tornado on May 26. According to the National Weather Service:
In 2013, the American Society of Civil Engineers published a study disputing the tornado's initial EF5 rating, based on surveying damage on over 150 structures within a six-mile segment of the storm's path. According to the report, over 83% of the damage was caused by wind speeds of 135 mph (217 km/h) or less, the maximum wind speed of an EF2 tornado. An additional 13% was caused by EF3 wind speeds, and 3% was consistent with EF4 winds. The study found no damage consistent with wind speeds over 200 mph (320 km/h), the minimum threshold of an EF5 tornado. Researchers concluded that the inability to find EF5 damage was due to the absence of construction standards that were able to determine the necessary wind speeds. Bill Colbourne, a member of the engineering team that surveyed the damage, declared that "a relatively large number of buildings could have survived in Joplin if they had been built to sustain hurricane winds."
However, the EF5 rating stood. The NWS office in Springfield stated that their survey teams found only a small area of EF5 structural damage, and that it could have easily been missed in the survey (at and around St. John's Medical Center). Bill Davis, head of Springfield's NWS office, said that the results of the study "do not surprise me at all," adding that "there was only a very small area of EF5 damage in Joplin...we knew right off the bat there was EF4 damage. It took us longer to identify the EF5 damage and that it would take winds of over 200 mph (320 km/h) to do that damage." Additionally, the basis for the EF5 rating in Joplin was mainly contextual rather than structural, with non-conventional damage indicators such as the removal of concrete parking stops, manhole covers, reinforced concrete porches, driveways, and asphalt used to arrive at a final rating. The presence of wind rowed structural debris, instances of very large vehicles such as buses, vans, and semi-trucks being thrown hundreds of yards to several blocks from their points of origin, the fact that some homeowners never located their vehicles, and the overwhelming extent and totality of the destruction in Joplin were also taken into consideration.
According to a detailed damage survey by Timothy P. Marshall, a majority of houses were destroyed at winds of EF2-3 strength. However he identified 22 well anchored houses which were assigned EF5 ratings.
On January 23, 2025, Anthony W. Lyza with the National Severe Storms Laboratory along with Harold E. Brooks and Makenzie J. Kroca with the University of Oklahoma’s School of Meteorology published a paper to the American Meteorological Society regarding the EF5 drought. In the paper, the researchers stated the justification for the tornado's EF5 rating was initially 22 homes that were completely swept away, with only the concrete slab remaining. The paper then stated the aforementioned study by the ASCE which "found none of these to actually be EF5". It is then noted a 2012 study published by Christopher D. Karstens, Timothy P. Marshall, and two others which stated, "that the movement of parking stops likely justifies keeping the rating."
On May 24, 2011, a long-track and extremely powerful tornado struck the areas near or within the communities of El Reno, Piedmont, and Guthrie. Not long after touching down, the tornado struck the Cactus 117 oil drilling rig site, completely destroying it. When it hit, the rig's pipes and drill head were inserted deep in the well's borehole, which provided the drilling pipe with 200,000 lb (91,000 kg) of downforce. Despite this, and despite the fact that the drilling rig weighed 862 metric tons—or almost two million pounds—the rig was toppled onto its side and rolled several times. The well's blowout preventer was left bent at a 30-degree angle to the north. Elsewhere on the site, vehicles and cargo containers were lofted into the air and tossed. Twelve workers were on the site when the tornado struck, and took shelter in the site's change house (a steel container serving as a locker room). Tied down by four steel cables anchored 5.5 feet (1.7 m) deep in the ground, the container was pummeled with debris. One cable broke and the container was dented, but all twelve workers survived without serious injury.
Despite not being an official damage indicator on the Enhanced Fujita scale, the National Weather Service Norman, Oklahoma rated the damage to the Cactus 117 oil drilling rig EF5 with winds of at least 210 miles per hour (340 km/h); the only damage caused by the tornado to receive an EF5 rating. Mechanical engineer Ethan Moriarty noted in 2023 that changes in procedures with how the EF-scale is applied in the 2020s, a single damage indicator would not be enough to rate the tornado as a whole EF5.
Prior to striking the oil drilling rig, the tornado was being monitored by a truck-mounted Rapid-Scan X-band Polarimetric (RaXPol) mobile Doppler weather radar, operated by the University of Oklahoma's Advanced Radar Research Center (ARRC) led by Howard Bluestein. That radar, stationed near the intersection of Smith Road and Walbaum Road less than two miles (3.2 km) south of I-40, captured the "first polarimetric, rapid-scan, mobile Doppler weather radar dataset of an EF-5 tornado." As the tornado moved towards I-40 to the southeast of the RaXPol radar, it detected some of the fastest wind speeds ever measured on the planet. Interpretations slightly differ: the maximum instantaneous radial velocity sampled by the radar was originally reported as having been 124.8 m/s (279 mph), measured 200–230 feet (60–70 m) above the ground at 4:00:26 p.m.; however, the maximum velocity was later reported as having been 132.1 m/s (295 mph) measured ~72 feet (22 m) "above radar level" at 4:00:39 p.m. in a 2014 paper by Bluestein et al. on the use of radar data for tornado ratings. Maximum radial velocities were also reported to have remained "greater than 120.0 m/s (268 mph) for several minutes." Additionally, multiple consecutive radar scans were averaged to yield an estimated 2-second average radial velocity of 118.4 m/s (265 mph) and an estimated 4-second average velocity of 110.8 m/s (248 mph). This was reported as "likely to be an underestimate of the true 2- and 4-s average wind speeds."
The instantaneous velocity readings taken are not directly equivalent to the three-second gust at 33 feet (10 m) that the Enhanced Fujita scale attempts to estimate, but they mark the second-highest wind speed ever recorded in a tornado, after wind speeds of approximately 135 m/s (300 mph) were recorded in both the 1999 Bridge Creek–Moore tornado and a sub-vortex within the 2013 El Reno tornado. Where the most intense winds are generally present in a tornado is an unresolved question, but the limited existing research suggests that wind speeds are likely to be highest closer to the ground.
On March 2, 2012, a large, long-tracked tornado struck the communities of New Pekin, Henryville, Marysville and Chelsea, Indiana. On March 6, the National Weather Service Louisville, Kentucky rated the worst of the damage EF4 with winds of 175 miles per hour (282 km/h). A decade later in 2022, the National Weather Service office in Louisville referred to a possible EF5 damage location at a demolished house, where a pickup truck was blown away and never found and a backhoe was deposited into the basement of the house.
On May 20, 2013, a large and violent tornado struck Moore, Oklahoma and surrounding areas. Less than 24 hours after the tornado, on May 21 at 1:10 PM CDT, the National Weather Service Norman, Oklahoma (NWS Norman), rated the tornado EF4 with winds of at least 190 miles per hour (310 km/h). At 2:50 PM CDT, less than 24 hours since the tornado had touched down, the NWS Norman upgraded the tornado's rating to EF5 with winds of 200–210 miles per hour (320–340 km/h). Shortly after the tornado, the Associated Press stated that the power of the Moore tornado "dwarfs" the atomic bombing of Hiroshima by "8 times to more than 600 times". The tornado's rating was officially finalized as EF5 with winds of 210 miles per hour (340 km/h).
Prior to hitting Moore, the tornado struck the Orr Family Farm and the Celestial Acres horse training area. Every building at Celestial Acres was either leveled or swept away at EF4 intensity, the ground on the property was scoured to bare soil, debris from structures was granulated, and vehicles were thrown and stripped down to their frames. Surveyors noted that based on the contextual damage, the tornado was likely at EF5 intensity in this area, though the construction quality of the affected buildings only permitted an EF4 rating.
The tornado then heavily scouring an open grassy field before impacting Briarwood Elementary School, which was completely destroyed. The NWS Norman originally rated this damage EF5, but further evaluation and a 2014 study published by the American Meteorological Society revealed evidence of poor construction at the school, and the rating was downgraded to EF4. Two 12,000-gallon water tanks that were also swept off of the Orr Family Farm grounds were thrown into this area; the roof of Briarwood Elementary was struck by one of them − potentially aiding in compromising the building's structural integrity as it bent the steel girders that held up the roof − shortly before the main vortex struck the building, while the other fell onto and destroyed a home a few blocks east of the school.
As the tornado entered western Moore, an anchor-bolted home that was reduced to a bare slab in this area was initially rated EF5 by the NWS Norman, but was later downgraded to EF4 as closer inspection of the foundation revealed that the anchor bolts were missing their nuts and washers. The tornado then destroyed Plaza Towers Elementary School at EF4 intensity, where seven children were killed when a cinder block wall collapsed on top of them. More than a dozen homes in a subdivision just to the south of Plaza Towers Elementary were swept cleanly away, though they were revealed to have been nailed rather than bolted to their foundations, and damage to this subdivision was subsequently rated EF4, though the tornado was likely violent as lawns in this area were completely scoured down to bare soil.
A preliminary study of Briarwood Elementary School conducted in September 2013 by a group of structural engineers found some structural deficiencies that led to its collapse during the tornado. Chris Ramseyer, a structural engineer and an associate professor at the University of Oklahoma determined that the building's walls that were not reinforced with concrete, there had been a lack of connection between the masonry walls and support beams in several portions of the building, and anchor bolts were pulled from the ground by the tornado. Another engineer that was involved in the study stated that the deficiencies that Ramseyer pointed out were not uncommon building practices at the time, and that current building code standards would not ensure that Briarwood would have withstood winds in excess of 200 miles per hour (320 km/h).
On May 20, 2023, mechanical engineer Ethan Moriarty analyzed the tornado's damage; specifically, the steel propane tank thrown from the Orr Family Farm that flew over the Briarwood Elementary School, landing on a nearby house. In his analysis, Moriarty determined winds of approximately 209 miles per hour (336 km/h) were needed to throw the propane tank. In October 2024, Moriarty analyzed the tornado's damage in comparison to non-EF5 tornadoes. Moriarty noted how telephone poles were barely leaning only 80 yards (73 m) away from one of the locations which received an EF5 rating, which was similar to why the 2014 Mayflower–Vilonia tornado was only rated EF4 and not EF5 due to nearby small trees that were still standing near the worst of the damage.
On May 31, 2013, an extremely large, powerful, and erratic tornado struck around El Reno, Oklahoma. The tornado grew to an unprecedented width of 2.6 miles (4.2 km), becoming the officially widest-known tornado ever recorded in history. The intensity of the tornado has been a subject of internal debate within the National Oceanic and Atmospheric Administration. The agency uses the Enhanced Fujita Scale to rate and assess tornado intensity based on the damage left behind. This excludes the use of supplementary measurements, such as those from mobile radar, in concluding a tornado's intensity. Initially receiving an official EF3 rating based on damage, the El Reno tornado was subsequently upgraded to a radar-estimated EF5 rating, the highest on the scale, based on data from a mobile radar. The University of Oklahoma's RaXPol mobile Doppler weather radar, positioned at a nearby overpass, measured winds preliminarily analyzed as in excess of 296 mph (476 km/h). These winds are considered the second-highest ever measured worldwide, just shy of the 321 mph (517 km/h) recorded during the 1999 Bridge Creek–Moore tornado.
Revised RaXPol analysis found winds of 302 ± 34 mph (486 ± 55 km/h) well above ground level and ≥291 mph (468 km/h) below 10 m (33 ft), with some subvortices moving at 175 mph (282 km/h). The strongest winds occurred in small subvortices along the south side of the main vortex. The two most intense vortices occurred north and east of the intersection of 10th Street and Radio Road, about 3 miles (4.8 km) southeast of El Reno. The main funnel is believed to have had radar-estimated EF4 winds, with wind speeds around 185 mph (298 km/h). Radar-estimated EF5 winds were only found aloft and in the smaller vortices that revolved around this funnel at 110 mph (180 km/h). A revised analysis in 2015 revealed a peak wind of 313 mph (504 km/h). In March 2024, NOAA and OU published a new analysis, which estimated that winds may have reached up to anywhere between 115–150 m/s (257–336 mph; 414–540 km/h).
Rick Smith, the warning coordination meteorologist at the National Weather Service Weather Forecast Office in Norman, stated that this tornado was among a "super-rare" category within the EF5 rating. Smith also stated that it was fortunate the tornado did not track into more densely populated areas, particularly those within the Oklahoma City metropolitan area, "this would have been … I don't even want to imagine what it would have been." William Hooke, a senior policy fellow at the American Meteorological Society stated that, "[Oklahoma City] dodged a bullet...You lay that path over Oklahoma City, and you have devastation of biblical proportions."
On August 30, the National Weather Service office in Norman once again revised the intensity of the El Reno tornado. Keli Pirtle, a Public Affairs worker at the National Oceanic and Atmospheric Administration, stated that, "despite the radar-measured wind speeds, the survey team did not find damage that would support a rating higher than EF3. While the wind measurements from the mobile radars are considered reliable, NWS policy for determining EF-ratings is based on surveys of ground damage." The lack of EF5 damage was likely a result of the rural nature of the area, as the sub-vortices that contained the EF5 wind speeds did not impact any structures.
On April 27, 2014, a large and destructive tornado struck towns of Paron, Mayflower, Lake Conway, Vilonia and El Paso in Arkansas. The National Weather Service rated the worst of the damage caused by the tornado EF4 with winds of at least 190 miles per hour (310 km/h). The final rating of the tornado was a source of controversy, and the National Weather Service office in Little Rock, Arkansas, noted that if this tornado occurred prior to the change to the Enhanced Fujita Scale in 2007, it likely would have been rated as an F5 due to numerous homes being swept clean from their foundations. However, it was revealed that almost every home in Vilonia lacked anchor bolts and were anchored with cut nails instead. The new scale accounts for homes that use cut nails instead of anchor bolts, which do not effectively provide resistance against violent tornadoes.
The final decision on an EF4 rating was based on this as well. However, meteorologist, structural and forensic engineer Timothy P. Marshall noted in his survey of the damage that the rating assigned was "lower bound", and despite the presence of construction flaws, this doesn't rule out "the possibility that EF5 winds could have occurred." Further inspection from surveyors revealed that one home that was swept away along E Wicker St. was indeed properly bolted to its foundation. However, an inspection of the context surrounding the house revealed that small trees in a ditch near the home were still standing, and that the residence had possibly been pummeled by heavy debris from downtown Vilonia, exacerbating the level of destruction.
On January 23, 2025, Anthony W. Lyza with the National Severe Storms Laboratory along with Harold E. Brooks and Makenzie J. Kroca with the University of Oklahoma’s School of Meteorology published a paper to the American Meteorological Society, where they stated the tornado in Vilonia was an "EF5 candidate". It was also explained that the EF5 starting wind speed should be 190 miles per hour (310 km/h) instead of 201 miles per hour (323 km/h).
On June 16, 2014, a powerful cyclic supercell struck northeast Nebraska, producing six tornadoes, including four violent tornadoes. One of the violent tornadoes, often referred to as the main Pilger twin tornado, destroyed a well-built farmhouse. The National Weather Service office of Omaha/Valley, Nebraska, rated the damage to the farmhouse EF4 with winds of 191 miles per hour (307 km/h). On January 23, 2025, Anthony W. Lyza with the National Severe Storms Laboratory along with Harold E. Brooks and Makenzie J. Kroca with the University of Oklahoma’s School of Meteorology published a paper to the American Meteorological Society, where they stated the main Pilger twin tornado was an "EF5 candidate", specifically at the aforementioned farmhouse. It was also explained that the EF5 starting wind speed should be 190 miles per hour (310 km/h) instead of 201 miles per hour (323 km/h).
On April 9, 2015, a violent and long-lived tornado struck the communities near Rochelle and in Fairdale, Illinois. The National Weather Service office in Chicago, Illinois, rated the tornado EF4 with winds of at least 200 miles per hour (320 km/h), a single mile per hour shy of an EF5 rating. This rating was based on the several structures and an entire farmstead that were completely leveled. Near one of these leveled homes, the tornado moved part of a concrete walkway through the ground. In 2022, Walker Ashley, a PhD meteorology professor at the Northern Illinois University, stated, "there's still some debate, even to this day [between meteorologists] as to whether it should have been categorized as an EF5". On January 23, 2025, Anthony W. Lyza with the National Severe Storms Laboratory along with Harold E. Brooks and Makenzie J. Kroca with the University of Oklahoma’s School of Meteorology published a paper to the American Meteorological Society, where they stated the tornado in Rochelle was an "EF5 candidate". It was also explained that the EF5 starting wind speed should be 190 miles per hour (310 km/h) instead of 201 miles per hour (323 km/h).
On April 13, 2019, a strong tornado struck near the towns of Greenwood Springs and Smithville in Mississippi. The National Weather Service office in Memphis, Tennessee rated the EF2. In July 2022, researchers with the University of Oklahoma, the National Severe Storms Laboratory, and the University of Alabama in Huntsville, published a paper with the American Meteorological Society, where they noted "this tornado produced forest devastation and electrical infrastructure damage up to at least EF4 intensity". Near the end of the report, it was stated that this was "a violent tornado, potentially even EF5 intensity." The paper was also placed into the National Oceanic and Atmospheric Administration's Library.
On April 12, 2020, an enormous and deadly tornado struck the southeastern parts of Bassfield and directly struck the communities of Soso, Moss, and Pachuta, Mississippi, as well as rural areas near Seminary and Heidelberg, Mississippi. The National Weather Service office in Jackson, Mississippi rated the tornado EF4 with winds of at least 190 miles per hour (310 km/h), based on a well-anchored wooden cabin that was obliterated and swept clean, with the metal roof being completely stripped away. Despite how well-built the home was, high-end EF4 rating was kept due to minor structural issues along with the suspicion a truck slammed into the home, compromising the structure.
On January 23, 2025, Anthony W. Lyza with the National Severe Storms Laboratory along with Harold E. Brooks and Makenzie J. Kroca with the University of Oklahoma’s School of Meteorology published a paper to the American Meteorological Society, where they stated the tornado in Bassfield was an "EF5 candidate". It was also explained that the EF5 starting wind speed should be 190 miles per hour (310 km/h) instead of 201 miles per hour (323 km/h).
On August 7, 2020, a photogenic tornado struck in southern Manitoba, passing near the towns of Virden and Scarth. Damage by the tornado was rated (C)EF3 by the Northern Tornadoes Project on August 8.
On August 1, 2024, four professors at the University of Western Ontario and employees of the Northern Tornadoes Project, published a paper through the American Meteorological Society where they analyzed two vehicles thrown by the tornado. The researchers determined that the vehicles have to have been picked up at least 1 metre (1.1 yd) vertically in the air and they were thrown 30 to 100 metres (33 to 109 yd) horizontally once picked up. This would have required the tornado to have had winds of at least 110 m/s (250 mph), which the researchers noted was well above the criteria for an EF5 tornado. At the end of the analysis, the researchers stated, "the lofting wind speeds given by this model are much higher than the rating based on the ground survey EF-scale assessment. This may be due to the current tendency to bias strong EF5 tornadoes lower than reality, or limitations in conventional EF-scale assessments".
On June 24, 2021, a rare, violent, and deadly long-tracked tornado struck several villages in the Hodonín and Břeclav districts of the South Moravian Region of the Czech Republic. The European Severe Storms Laboratory, along with the Czech Hydrometeorological Institute (CHMI), Slovak Hydrometeorological Institute (SHMÚ), and Charles University, rated the worst of the damage IF4 on the new International Fujita scale. In Moravská Nová Ves and Mikulčice, hundreds of buildings were severely damaged or destroyed, including a few well-built brick and masonry homes that were completely leveled. The concrete exterior walls of structures that remained standing were scarred and impaled by flying projectiles. A few trees were completely stripped clean of all bark. In the towns, three locations sustained IF4 damage. The first location was a row of newly built homes. "Here, an IF4 rating was assigned to the damage of three well-built brick structures. One of the brick structures was completely destroyed, which would warrant an IF5 rating. However, a rather weak connection between the roof and the walls was found, which prevented the damage from being assigned an IF5 rating. Another structure that was completely destroyed was still under construction. Debris from the houses were carried over the following field along considerable distances." In all, a total of 1,200 buildings were damaged or destroyed by the IF4 tornado, which had an estimated peak windspeed of 380 km/h (236.1 mph) and 14 different locations sustained IF4 level damage.
On December 10, 2021, a deadly and violent tornado struck Western Kentucky, particularly the towns of Mayfield, Princeton, Dawson Springs, and Bremen. On December 16, the National Weather Service (NWS) office in Paducah, Kentucky rated the tornado EF4 with winds of 188 miles per hour (303 km/h) in the city of Mayfield, Kentucky and 190 miles per hour (310 km/h) in the town of Bremen, Kentucky. Following the rating being released, Gregory Meffert, the lead forecaster at the NWS Paducah stated, "it is not out of the question that at some point in time in the future that this could be upgraded to a five".
In 2022, Timothy Marshall, a meteorologist, structural and forensic engineer; Zachary B. Wienhoff, with Haag Engineering Company; Christine L. Wielgos, a meteorologist at the National Weather Service of Paducah; and Brian E. Smith, a meteorologist at the National Weather Service of Omaha, published a damage survey of portions of the tornado's track, particularly through Mayfield and Dawson Springs. The report notes: "the tornado damage rating might have been higher had more wind resistant structures been encountered. Also, the fast forward speed of the tornado had little 'dwell' time of strong winds over a building and thus, the damage likely would have been more severe if the tornado were slower." Marshall later stated in 2023 that the Western Kentucky tornado was "the closest to EF5 that I can remember" since the Moore EF5 of 2013. Marshall also stated some of the buildings struck by the strongest winds "were horribly constructed and could not resist 100 or even 150 mph wind let alone 200 mph", meaning it was "impossible to know if EF5 winds affected them".
On January 23, 2025, Anthony W. Lyza with the National Severe Storms Laboratory along with Harold E. Brooks and Makenzie J. Kroca with the University of Oklahoma’s School of Meteorology published a paper to the American Meteorological Society, where they stated the tornado's damage inside Mayfield was an "EF5 candidate".
On April 29, 2022, a well documented tornado struck the city of Andover, Kansas. On May 2, the National Weather Service office in Wichita, Kansas rated the tornado EF3 with winds of at least 165 miles per hour (266 km/h). However, this was later decreased to 155 miles per hour (249 km/h). On October 26, 2022, at the American Meteorological Society's 30th Conference on Severe Local Storms, the European Severe Storms Laboratory (ESSL) presented evidence through photogrammetry using a drone video taken by Reed Timmer. In the presentation, ESSL showed that the tornado had winds of at least 118.0 metres per second (264 mph) and a graphic showing the tornado was approximately IF4 to IF5 intensity on the International Fujita scale.
On March 24, 2023, a large and multi-vortex wedge tornado struck the city of Rolling Fork and the town of Silver City, Mississippi. On March 27, the National Weather Service (NWS) office in Jackson, Mississippi, along with the help of the National Severe Storms Laboratory (NSSL) and the PERiLS Project, rated the tornado EF4 with winds of 170 miles per hour (270 km/h). On June 6, the National Weather Service upgraded the tornado to EF4 with winds of 195 miles per hour (314 km/h), following "consultation from tornado damage and structural engineering experts" and additional surveys conducted by the NSSL, University of Oklahoma, the NIST, and Haag Engineering.
In March 2024, Logan Poole, a meteorologist and damage surveyor with the National Weather Service in Jackson, Mississippi gave an interview regarding the tornado and why it was rated EF4 rather than EF5. In the interview, Poole stated:
On January 23, 2025, Anthony W. Lyza with the National Severe Storms Laboratory along with Harold E. Brooks and Makenzie J. Kroca with the University of Oklahoma’s School of Meteorology published a paper to the American Meteorological Society, where they stated the Rolling Fork tornado was an "EF5 candidate" at the floral shop. It was also explained that the EF5 starting wind speed should be 190 miles per hour (310 km/h) instead of 201 miles per hour (323 km/h).
On June 21, 2023, an intense tornado touched down north of the town of Matador, Texas, travelling south. The tornado, initially wedge shape, began to shrink and intensify, leading to extraordinarily intense vegetation damage. On the outskirts of town, a barn and home were destroyed and swept clean with the concrete foundation cracked and shifted. Another home was also destroyed, with a truck parked there found half a mile away, mangled and entirely unrecognizable. The engine of the truck was thrown on the opposite side of the highway into a lake. Destroying more homes and continuing past the highway intersection, the tornado gutted and flattened a new Dollar General, snapping multiple ballards and pulling out support beams that were anchored into the concrete foundation and twisting them. Three days later, the National Weather Service office in Lubbock, Texas, with "consultation with engineers from the Texas Tech University National Wind Institute", rated the tornado EF3 with winds of at least 165 miles per hour (266 km/h).
Following the tornado, several meteorologists and storm chasers questioned the tornado's EF3 rating saying it was "a gross underestimate of such a violent tornado", as it completely leveled and swept away multiple structures and produced extreme contextual damage to vehicles and vegetation. In addition, the tornado was slow moving, which may have exacerbated the severity of the damage. Chief meteorologist for KWTV-DT David Payne stated the damage in Matador, "looks like EF4 damage to me".
On July 1, 2023, a violent (C)EF4 tornado, struck the rural Mountain View County in Alberta, Canada, causing damage particularly between the towns of Didsbury and Carstairs. On July 4, the Environment and Climate Change Canada (ECCC), the Prairie and Arctic Storm Prediction Centre (PASPC), and the Northern Tornadoes Project (NTP) published a joint-damage survey, rating the tornado low-end EF4 with winds of 275 kilometres per hour (171 mph). This rating was based on major damage at a farmstead, where a well-built house was completely leveled with debris scattered across nearby fields. A large 22,000-pound (10,000 kg) combine near this home was thrown 50 m (160 ft) before being rolled a further 50 to 100 m (160 to 330 ft), however, the combine was unable to be used in the rating of the tornado.
On August 1, 2024, four professors at the University of Western Ontario and employees of the Northern Tornadoes Project, published a paper through the American Meteorological Society where they determined the combine harvester was likely lofted roughly 1.26 m (1.38 yd) into the air, with median estimated winds of 118 m/s (260 mph) being needed to lift and thrown the combine. At the end of the analysis, the researchers stated, "the lofting wind speeds given by this model are much higher than the rating based on the ground survey EF-scale assessment. This may be due to the current tendency to bias strong EF5 tornadoes lower than reality, or limitations in conventional EF-scale assessments".
On May 21, 2024, a violent and destructive tornado struck the communities of Villisca, Nodaway, Brooks, Corning, and Greenfield in southwestern Iowa. On May 23, the National Weather Service office in Des Moines, Iowa, rated the tornado EF4 with estimated winds between 175–185 miles per hour (282–298 km/h). This was later revised up to 185 miles per hour (298 km/h).
On the day of the tornado, the Doppler on Wheels (DOW) team made a very preliminary analysis, suggesting a Doppler on Wheels measured winds of at least 90 m/s (200 mph). The next day, a further preliminary analysis by the DOW team determined that a Doppler on Wheels measured winds of at least >250 mph (400 km/h), "possibly as high as 290 mph (470 km/h)" at 48 yards (44 m) above the surface, as the tornado moved through the town. Pieter Groenemeijer, the director of the European Severe Storms Laboratory noted that "on the IF-scale, 250 mph measured below 60 m above ground level is IF4 on the IF-scale, 290 mph is IF5."
On June 24, after further analysis, the report was revised to winds of 308–319 mph (496–513 km/h) in a brief 1 second gust, based on the measurement of 263–271 mph (423–436 km/h) at 36–38 yards (33–35 m) above the surface. This preliminary data suggests that the Greenfield, Iowa EF4 tornado had the third highest measured wind speeds recorded in a tornado and was the third tornado to ever been recorded to be over 300 mph.
Across the street from the Adair County Memorial Hospital, the tornado ripped new concrete parking lot stop blocks from the ground, which were installed sometime after August 2023. Mechanical engineer Ethan Moriarty calculated that winds of at least 247 miles per hour (398 km/h) was needed to rip the concrete stop blocks out of the ground if they were cracked prior to being pulled up, or 283 miles per hour (455 km/h) if they were uncracked prior to being ripped out of the ground. The tornado, once nearly a mile wide at one point, had reduced in size significantly before impacting Greenfield, with the conservation of angular momentum potentially being responsible for the tornado's intensity near the end of its life. In the conclusion of his analysis, Moriarty stated that he believed the tornado was "without question a tornado capable of EF5 damage", while stating that, had the tornado been rated on a scale other than the Enhanced Fujita scale, it may have received a higher rating.