The Highest Winds Ever Measured by Mobile Doppler Radar in Five Violent Tornadoes

“In small, intense tornadoes, and especially in multiple vortices, radar observations of debris may be severely underestimating air motions.” – The Center for Severe Weather Research

Image of the violent Spencer, South Dakota, tornado of 1998. Winds over 260 mph were recorded as the tornado obliterated 100 homes and killed six people. (StormStock)

□ Mobile doppler radar remains the only quantitative and practical technology able to analyze tornadic winds. Direct observations in winds over 200mph are next to impossible, so doppler radar allows scientists the opportunity to – from a safe distance – see behind the curtain of dirt and debris. It is important to understand, however, that doppler devices do not actually “measure” anything. Instead, they analyze the motion of debris particles within tornadoes and provide a statistical range from which tornadic wind speeds can be estimated.

Despite over two decades of active use, only a handful of violent tornadoes have ever been documented at close range. Of the tornadoes that have been tracked, only a fraction of their total path lengths were thoroughly analyzed. So doppler velocities, while useful, are by no means an objective measurement that can be used to compare or categorize individual storms.

Image of the Bridge Creek tornado from the Doppler On Wheels (DOW) right as the record 300 mph+ velocity was recorded. The tornado was in the process of scouring grass and pavement from the ground in Grady County. Higher winds have undoubtedly occurred in other E/F5 tornadoes.

1. The highest reading ever recorded by mobile doppler radar was during the May 3rd, 1999, Great Plains tornado outbreak. The world-record velocity was taken just before 7pm as the F5 Bridge Creek tornado roared towards the Oklahoma City metro area. Originally calibrated at 318 mph, the reading was later reduced to 301 mph +/- 20 mph (135 +/- 10 m/s). A more accurate interpretation of the data is the statistical range the DOW estimated – 280 mph to 322 mph. At two standard deviations (2% likelihood) the measurement would be 369 mph, according to the DOW website. The reading was taken at a fairly low altitude (about 95 ft above the ground) but the surface level winds may have been slightly less – probably in the 260 to 290 mph range. At the same time, recent research in powerful hurricanes has shown that surface winds, which are generally estimated to be 10 to 15% lower than flight level winds, can actually be equal to or even exceed high altitude winds in exceptionally powerful, rapidly intensifying tropical cyclones (Uhlhorn, 2012). While these observations are specific to hurricanes, the same principle may apply to powerful tornadoes undergoing a period of rapid intensification.

The DOW does not directly measure winds but instead the movement of airborn particles. No attempt has ever been made to compare DOW observations with actual ground readings in violent tornadoes for obvious reasons. The DOW team admits that their technology likely fails to account for the many small-scale vortices that exist in strong tornadoes as well as the vertical component of tornadic winds.

The Bridge Creek tornado caused extreme ground scouring across the majority of its path. (Image by Bob Webster)

Image of the F5 tornado as analyzed by the DOW. Note the hurricane-like “eye” at center. Survivor testimony and scientific data indicates tornadoes, particularly large tornadoes, have calm centers with light winds.

2. Besides the Bridge Creek event, only one other E/F5 tornado has been analyzed by mobile doppler radar. The El Reno, Oklahoma, EF5 tornado formed on May 24th, 2011, during a large scale outbreak that also produced the deadly Joplin tornado two days earlier. The tornado killed nine people and left a streak of scoured earth as it thundered through rural areas west and north of Oklahoma City. Though still not officially made public, a rapid scanning mobile radar recorded a radial velocity of  280 mph (125 m/s) about 220 ft above ground level early in the tornado’s life. The tornado was given an EF5 rating based on the doppler measurement, and its intensity is currently quoted in NWS literature as having been “greater than 210mph” at ground level. The mobile radar team was only able to follow the tornado for part of its 65-mile long path, so it is very possible the tornado had higher winds in later stages of its life.

The El Reno tornado had a significantly longer path than the Bridge Creek tornado and may also have been more intense, though such comparison is purely speculation. The tornado became rain wrapped minutes after touching down and was obscured for much of its life. The fatality rate (the number of fatalities divided by the total number of people in the tornado’s path) in the El Reno/Piedmont tornado was significantly higher than the Bridge Creek tornado.

Severe tree and vehicle damage from the EF5 El Reno tornado. During the May 2011 tornado outbreak in Oklahoma, there were several other tornadoes that likely reached EF5 intensity. The Chickasha tornado formed one hour after the El Reno tornado and was well-documented by storm chasers. It scoured grass and pavement from the ground and likely had winds well into the EF5 range. (Image by Jim LaDue)

Video still of the El Reno tornado. For much of its life the EF5 tornado was a mile wide and obscurred by precipitation. (Image by JeopardyTempest)

3. The Red Rock, Oklahoma tornado on April 26th, 1991 was part of a larger outbreak that also caused the infamous Andover, Kansas F5 tornado. Of all the violent tornadoes that day, the Red Rock tornado was likely the most intense. It had the most impressive radar presentation and the longest damage path. The tornado hit very little as it roared through sparsely populated countryside and was only given an F4 rating as a result. A team headed by Howard Bluestein recorded a velocity of 268 mph in the tornado’s mature stage. This was the highest reading ever recorded using mobile doppler technology up until the Bridge Creek tornado eight years later. The Red Rock measurement was taken about 550 ft above the ground. Like most of the tornadoes tracked by mobile doppler radar, only a part of its life cycle was analyzed, and higher winds may have occurred in other stages of its development.

The Red Rock tornado was exceedingly violent, and video from storm chasers show it had some of the most impressive tornadic motion ever recorded.

View of the Red Rock tornado close to the time the 268 mph velocity was recorded.

4. The Spencer, South Dakota F4 tornado was followed by the DOW as it travelled generally to the east-southeast on May 30, 1998. The DOW recorded ground relative wind-speeds as high as 264 mph (118 m/s) close to the time the tornado passed through the small town of Spencer (Wurman, 2005). The measurement was taken at a fairly low altitude – 160 ft – but still well above what the NWS constitues as “ground level.” Only a tiny section of the tornado’s path crossed over man-made structures, so the tornado’s true damage potential was likely not realized. It was given an F4 rating after a damage survey was conducted, but many researchers believe the tornado had F5 potential. Six fatalities occurred in Spencer, five of them in a two story apartment building that was obliterated.

An interesting feature of the Spencer tornado was revealed when the DOW measurements were compared with a ground damage survey. The tornado was shown to have a pronounced eye, and much like a hurricane, the winds on the right side of the tornado were significantly stronger than the winds on the left side due to the addition of the tornado’s forward momentum (Wurman, 2005). The high-end F4 damage was all south of the torndo’s center whereas areas north of the eye had lighter (F1 – F2) damage. According to the DOW analysis, the worst affected areas in Spencer experienced hurricane force winds for two minutes and violent (200mph+) winds for about 20 seconds. The tornado was often obscurred by dust, but video from storm chasers show that the storm had extremely rapid rotation.

Aerial view of F4 damage in Spencer. The large building at right is where five deaths occurred.

5. The Mulhall, Oklahoma tornado occurred on the same day as the Bridge Creek tornado on May 3rd, 1999. Several researchers believe this tornado was more violent than its infamous cousin, and the DOW measurements revealed the Mulhall tornado was significantly larger. The DOW estimated a velocity of 257 mph (115 m/s) and one CSWR article mention readings of 277 mph to 299 mph in regards to this tornado. The veracity and context of the higher readings is unknown (DOW Measurements of Extreme Winds…, 2003). The Mulhall tornado’s extreme winds formed a giant circle one mile across with a large, calm eye at center. The tornado had hurricane force winds extending over an area four miles across, making it the largest tornado ever analyzed by the DOW. The tornado only caused two fatalities as it swept through largely rural areas north of Oklahoma City, but the storm had the potential to produce a huge swath of E/F4 to E/F5 damage had it struck a heavily populated area.

Image of the Mulhall tornado taken from the DOW. The tornado was rated F4, but had it passed over more structures it likely would have received an F5 rating.

Equal area comparison between the Mulhall and Bridge Creek tornadoes from cswr.org. The Mulhall tornado had similar but slightly weaker winds at the time of analysis but the size of the tornado was remarkable. The tornado’s core missed the center of Mulhall by nearly a mile but the broad region of winds caused severe damage across the town.

Measurements from mobile doppler radars taken before 2007 were often in agreement with the now unused Fujita Scale. Even when the estimates are reduced by 10 to 15% to account for possible altitude effects, the velocities were in agreement with the Fujita Scale. The DOW often found winds higher than the tornado’s damage indicated. Popular opinion now emphasizes being as conservative as possible when estimating tornado windspeeds. The new “Enhanced Fujita Scale” is more specific in its description of tornado damage indicators, but the reduced windspeed ranges likely underestimate the surface winds in violent tornadoes.

The List of the Strongest Tornadoes Ever Recorded: Part I

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View of the Rainsville, Alabama, tornado as it passes over Lingerfelt Road at maximum intensity. Homes in the area were swept completely away and pavement was scoured from driveways. An 800lb safe anchored to a foundation was thrown 200 yards. The steel door to the safe was ripped open and completely off. At the same residence, a large, concrete porch was shattered and blown away, and cement columns were ripped from the ground (NWS Survey, 2011). These are among the most impressive and powerful instances of tornado damage ever recorded. (Video by YORKBAMA)

□ Over a thousand google searches every month ask the question – “What was the strongest tornado ever recorded?” In all likelihood, a quarter of those searches came from me. Truthfully, there is no list that can honestly answer that question. Only a fraction of E/F5 damage paths are thoroughly surveyed, and only a fraction of all tornadoes capable of inflicting E/F5 damage are ever rated as such.

Three views of extreme tornado damage from the 2011 season (intensity increasing from left to right). At left, the Phil Campbell tornado left a streak of damaged grass and empty foundations near Cornelius Drive. At center, pronounced grass scouring following the El Reno tornado near Oklahoma City. At right, extreme vegetation scouring and home damage from the Smithville tornado. Had all three tornadoes caused comparable damage, the El Reno tornado would have been ranked the lowest due to its modest forward speed.

Three views of extreme tornado damage from the 2011 season (intensity increasing from left to right). At left, the Phil Campbell tornado left a streak of damaged grass and empty foundations near Cornelius Drive. At center, pronounced grass scouring following the El Reno tornado near Oklahoma City. At right, extreme vegetation scouring and home damage from the Smithville tornado. Had all three tornadoes caused comparable damage, the El Reno tornado would have been ranked the lowest due to its modest forward speed.

For the purposes of this list, damage severity is the primary categorization variable, along with some consideration for wind duration. Special emphasis will be placed on tornadoes powerful enough to scour vegetation and pavement from the ground. To eliminate the many tornadoes that never hit a man-made structure, only tornadoes that caused fatalities are examined. The list is skewed towards more recent events as there is far more information available today than there was twenty years ago. Tornadoes before 1970 are not considered.

The indefinitive list of the strongest tornadoes ever recorded:              

1. Jarrell, Texas – May 27, 1997

2. Smithville, Mississippi – April 27, 2011

3. Kemper County (Philadelphia), Mississippi – April 27, 2011 

4. Bridge Creek, Oklahoma – May 3, 1999    

5. Bakersfield Valley, Texas – June 1, 1990 

6. Phil Campbell, Alabama – April 27, 2011

7. El Reno, Oklahoma – May 24th, 2011

8. Smithfield, Alabama – April 4, 1977    

9. Brandenburg, Kentucky – April 3, 1974 

10. Andover, Kansas – April 26, 1991

11. New Hartford (Parkersburg), Iowa – May 25, 2008

12. Joplin, Missouri – May 22, 2011

13. Guin, Alabama – April 3, 1974 

14. Moore, Oklahoma – May 20, 2013

15. Mulhall, Oklahoma – May 3, 1999

16. Wheatland, Pennsylvania – May 31, 1985

17. Rainsville, Alabama – April 27, 2011

18. Barneveld, Wisconsin – June 8, 1984

19. Will County (Plainfield), Illinois – August 28, 1990

20. Xenia, Ohio – April 3, 1974

While far from definitive, this list is the result of literally hundreds of hours of research, e-mails across the country and conversations with other storm chasers. I believe it is as accurate a list as is available. It is flexible and always open to change.

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5. Bakersfield Valley, Texas – June 1, 1990

The Bakersfield Valley tornado of 1990 caused minimal damage and only two fatalities in largely unpopulated sections of Pecos County, Texas.

The Bakersfield Valley tornado of 1990 caused minimal damage and only two fatalities in largely unpopulated sections of Pecos County, Texas. Survey reports indicated, however, that the tornado was among the most intense ever documented. At left, one of several oil tanks weighing 180,000lbs that was moved three miles by the storm. Severe ground scouring is visible in the foreground. At right, a road scoured of pavement. (Images by Wayne Greene)

□ On June 1, 1990, one of the most violent tornadoes ever surveyed touched down far south of Tornado Alley in the deserts of southwest Texas. No photographs exist of the early evening storm, but witnesses described the tornado as a “low, turbulent, debris-filled cylinder extending to the cloud base” (Storm Data, June 1990). The tornado quickly widened as it travelled to the east-southeast, eventually reaching a peak width of 1.3 miles. Due to the area’s sparsely populated nature, few buildings were struck in the tornado’s early stages.

The tornado narrowed slightly to approximately 0.7 miles in width as it approached several rural residences. One large, newly-built two-story home of excellent construction was completely obliterated, leading surveyors to award the damage an F4 rating (Woodall and Matthews, 1993). As the tornado continued eastward, it intensified further and left a pronounced streak of severe ground scouring. According to a survey report, the storm left “only a few rocks and an occasional greasewood or mesquite stump” (Storm Data, June 1990). Several roads were stripped of asphalt, including one that was left with a 300ft segment scoured down to the subgrade. Spiral marks indicative of suction vortices were also documented by surveyors (Woodall and Matthews, 1993).

Mid-way through its lifecycle, the storm became rain-wrapped and weakened slightly. Two fatalities occurred in vehicles near Farm to Market Road 305. One man was killed in a car thrown 165 yards, and another man was found dead in a truck recovered 50 yards from an adjacent road (Woodall and Matthews, 1993). After causing the fatalities, the tornado re-strengthened and may have reached an intensity maxima. The storm then entered an oilfield and unanchored three 500-barrell oil tanks, each weighing approximately 180,000lbs, and tossed and rolled them three miles to the east. Two of the oil tanks were tossed 600ft up the side of a hill with a steep incline (Storm Data, June 1990). Nearby, a drainage culvert was scoured of concrete and large oil pumps were damaged or destroyed (Storm Data, June 1990). After this point, the tornado struck no substantial structures and dissipated just after nightfall.

A stringent damage survey gave the tornado an F4 rating due to the residential damage. The severity of the ground scouring and tree damage, however, was among the most intense ever photographed. Additionally, the long-distance movement of massive oil tanks is perhaps the most impressive instance of tornado damage ever recorded.

The Bakersfield Valley event occurred in an area unaccustomed to violent tornadoes. At left, aerial view of the streak of severe ground scouring. At right, ground view of the disturbed earth vacant of all vegetation. (Image from Storm Data, June 1990).

The Bakersfield Valley event occurred in an area unaccustomed to violent tornadoes. At left, aerial view of the streak of severe ground scouring. At right, ground view of the disturbed earth vacant of vegetation and large rocks. (Images by Wayne Greene)

At left, image of a drainage culvert that was scoured of concrete. At right, one of the vehicles in which a fatality occurred.

At left, image of a drainage culvert that was scoured of cement (Image by Wayne Greene). At right, the remains of a vehicle in which a fatality occurred. In the worst affected areas, dense balls of wire and debris several feet in diameter were recovered, a highly unusual damage feature.

4. Bridge Creek, Oklahoma – May 3rd, 1999

Image of the Bridge Creek tornado around the time the world record velocity was recorded. The Doppler On Wheels can be seen at left.

□ Doppler radar observation of the Bridge Creek tornado has frequently led to it being cited as “the most powerful tornado ever recorded.” The DOW, headed by Josh Wurman, recorded the record velocity as the tornado tore through rural Grady County at maximum intensity. The reading, once quoted as 318mph (but later adjusted to 301mph +-20mph), remains the highest on record. It is important to note, however, that less than half of  1% of all violent tornadoes have been tracked by mobile doppler radar, so the few readings available are by no means a method of comparison to other E/F5 tornadoes. Additionally, doppler velocities are never analyzed at ground level, and do not constitute true “measurements.”

There is no doubt, however, that the Bridge Creek tornado was exceptionally violent. While deemed a “minimal F5” by one piece of NWS literature, the tornado caused some of the most impressive vegetation scouring ever surveyed. Media focused primarily on the tremendous damage in the Oklahoma City metro area, but the most intense damage occurred many miles southwest of the city in rural Grady County. Well-anchored homes were swept cleanly away, pavement was stripped from roads, trees were fully debarked and vehicles were thrown up to a mile, including one that was shredded and wrapped around a utility pole. A dozen fatalities occurred in a sparsely populated area near the Norman Spur of the H. E. Bailey Turnpike, a significant fatality rate considering the wide visibility of the storm. A further 24 deaths occurred after the tornado weakened slightly and ripped through Moore and housing developments near Tinker Air Force Base.

The tornado was extremely well-covered by local news stations, so nearly everyone in the tornado’s path had plenty of time to seek appropriate shelter. The death toll of 36 people made the Bridge Creek tornado the deadliest of the 90’s, yet still remarkably low considering the breadth of the destruction. A detailed morbidity report revealed that more than a third of the tornado’s victims were in a “recommended place”, meaning in an interior room in a frame home with no exterior walls, often with a mattress or other large object for protection (Sheryll Brown, 2001).

Looking at all seven “extreme” damage indicators (discussed at the end of post II), the damage path through Grady County is one of the most impressive in recent history. The tornado’s modest forward speed and large size, however, suggest that the duration of peak winds was significantly longer than some other E/F5 tornadoes.

Aerial view of F5 damage to a home in Grady County (a secondary source says this image depicts a home in Cleveland County). Extreme winds scoured vegetation from the ground, leaving behind a muddy aftermath unique to the most intense E/F5 tornadoes.

Remains of a well-constructed home. The large swath of grass scouring is clearly visible. Equally impressive is the damage to the remaining trees and shrubs, all of which have been completely debarked and bent to the northeast. Although tree bark is often partially removed in F3+ tornadoes, the complete stripping of low lying foliage is rare. (Image by Jim LaDue)

Iconic image of a mangled truck wrapped around a utility pole in Grady County. Vegetation scouring near Bridge Creek was some of the most intense ever documented.

At left, F5 damage to a row of houses in Eastlake Estates, a subdivision in Moore. At right, completely debarked trees in a field to the west of Eastlake Estates. (NWS, 1999)

3. Kemper County (Philadelphia),  Mississippi – April 27, 2011

Image from the only available footage of the Neshoba County tornado around the time it caused the extreme ground scouring that made it so notable. Taken near the town of Preston, MS. (lilbeejay1 – video link)

□ During the 2011 Super Outbreak, an exceptionally violent tornado touched down in rural Mississippi. A group of storm chasers captured the rapidly rotating tornado as it ripped apart trees and sped to the northeast at 60mph. Only a few buildings were struck by the tornado, so its true damage potential will never be known. Three woman were killed in Kemper County when a mobile home was lifted into the air and thrown more than 300 yards. An NWS survey team found no evidence that the mobile home had made contact with the ground, so it likely remained airborne the entire distance before disintegrating on impact (NWS, 2011). Nearby, a “well-built” home was swept away, and several vehicles were thrown long distances and wrapped around trees.

Footage of the tornado suggests that it remained fairly narrow as it approached the Neshoba County border. The storm further intensified and left deep scouring marks over a one mile area along Stokes Road. Surveyors noted that the narrow trenches, which were over 2ft deep in places, were approximately 10 to 20 yards wide and 50 to 100 yards long. Considering the forward speed of the tornado, it is likely the ditches were dug in less than two seconds by extremely powerful suction vortices imbedded within the main funnel. Massive trees weighing well over five tons were ripped out of the ground and lofted over a quarter mile from the edge of a wooded area, and several roads were stripped of pavement.

Violent tornadoes have been known to scour up to a foot of top soil from the surface, but the deep, penetrating ditches in Neshoba County appear to be unique. If there was ever evidence of winds over 300mph making direct contact with the ground, this is as good an example as there is. The lack of other damage indicators, however, leave open the unlikely possibility that the soil in the area was particularly vulnerable to the effects of violent tornadic winds.

Extreme ground scouring in Neshoba County, Mississippi. Most intense tornadoes scour the ground through the removal of topsoil, but the Neshoba County tornado penetrated the ground like a drill and tore out large clumps of dirt and rock. The soils in eastern Mississippi are primarily alluvial deposits with a high clay content, much like the soils found in the Great Plains.

Additional video frames of the severe ground scouring. Footage of the tornado around the time the damage occurred shows impressive, but not unprecedented rotational velocity. The vortex/vortices responsible for the trenches were likely hidden within the larger funnel.

Additional video frames of severe ground scouring. Footage of the tornado around the time the damage occurred shows impressive, but not unprecedented rotational velocity. The vortex/vortices responsible for the trenches were likely hidden within the larger funnel.

At left is severe damage to a car and a “well-built home” that was swept away. The building and vehicle damage occurred well before the tornado reached peak intensity. At top right, one of several roads that was stripped of pavement. At bottom right, one of the many large trees that originated from an unknown location.

2. Smithville, Mississippi – April 27, 2011

The Monroe County tornado directly over Smithville at maximum intensity. (Video by Surveyormike1)

□ During the 2011 Super Outbreak, one of the most violent tornadoes ever surveyed cut a path of devastation through rural Mississippi. The fast moving tornado touched down three miles southwest of the tiny town of Smithville and rapidly sped to the northeast at 70mph. Within seconds of touchdown, the storm was powerful enough to debark large pine trees. An extremely violent sub-vortex less than 50 yards wide developed at the edge of a wooded area two miles from the center of town. The inner core of the storm scoured a long trench through a field as it travelled parallel to Highway 25 towards Smithville. Seven deaths occurred in rapid succession as large homes on the north side of the highway were swept completely away while homes on the other side of the street suffered only moderate damage.

Less than three minutes after first reaching the ground, the massive, gray funnel enveloped more than half of Smithville, leading to another nine deaths east of Court Street. Large, well-constructed brick homes were swept cleanly from their foundations as the storm ripped through town in less than 20 seconds.  The EF5 damage and all the fatalities were focused within a narrow streak of incredibly intense damage that sliced through the northern side of town like a razor. Surveyors documented extensive vegetation scouring, completely debarked trees and vehicles that were lofted more than 3/4 of a mile. Some cars were pulverized into indiscernible pieces, and one truck remained missing at the time of the damage survey (NWS, 2011).

Approximately 50 frame homes and two dozen businesses were completely obliterated in the town of Smithville, and 16 people were killed. The death toll would likely have been much higher had the tornado not struck during work hours when many people were away from their homes. The tornado weakened not long after tearing through town but continued for an additional 34 miles. In total, 24 people lost their lives (the official NWS report lists 23 deaths).

The Smithville tornado was one of the most powerful tornadic events ever recorded and probably brought some of the strongest ground level winds of any tornado in recent history. A post detailing the tornado’s damage more thoroughly can be found here.

The Smithville tornado left a narrow streak of extreme damage as it sliced through town at 70mph. Grass was scoured from the ground and large, two story brick homes of excellent construction were swept cleanly away. The EF5 damage was clearly defined within a narrow corridor, but moderate to light damage occurred across most of the town.

The Smithville tornado left a narrow streak of extreme damage as it sliced through town at 70mph. Grass was scoured from the ground and large, two story brick homes of excellent construction were swept cleanly away. The EF5 damage was clearly defined within a narrow corridor, but moderate to light damage occurred across most of the town. Ground scouring and tree damage were noticeably more pronounced in Smithville than in Hackleburg, Phil Campbell, Oak Grove and Rainsville, three other communities impacted by EF5 tornadoes on April 27th, 2011. (Left image by JJ Jasper)

At left, a narrow strip of deep ground scouring west of Smithville, where the tornado entered a period of explosive intensification (Image by Mel Webster). At right, the tornado left some of the most extreme tree damage ever photographed.

At left, a narrow strip of deep ground scouring west of Smithville, where the tornado entered a period of explosive intensification (Image by Mel Webster). At right, the tornado left some of the most extreme tree damage ever photographed.

Two views of EF5 home damage and grass scouring. At left, two well-constructed homes were swept completely away on Monroe Street, leading to three fatalities. At right, the remains of a brick home west of town. (Images by Thomas Wells)

Aerial views of three well-constructed homes where fatalities occurred. Pronounced vegetation scouring is visible around the empty foundations. (Images by Thomas Wells)

At right, the remains of a well-constructed brick home that was swept away along Highway 237. Plumbing fixtures were ripped from the concrete foundation, and adjacent vegetation was stripped bare and nearly ripped from the ground. At right, large trees were stripped of all bark and branches as the tornado entered a forested area near Cemetery Drive.

At left, the remains of a well-constructed brick home that was swept away along Highway 237. Plumbing fixtures were ripped from the concrete foundation and adjacent vegetation was stripped bare and nearly pulled from the ground. At right, large trees were completely debarked as the tornado entered a forested area near Cemetery Drive. (Image by Christi Welch)

At left, mangled vehicles and debris from destroyed homes was left strewn among debarked trees at the edge of town. At right, grass scouring and high velocity impact marks, both indications of extreme intensity. (Images by Christi Welch)

At left, mangled vehicles and debris from destroyed homes was left strewn among debarked trees at the edge of town. At right, grass scouring and high velocity impact marks, both indications of extreme intensity. (Images by Christi Welch)

1. Jarrell, Texas – May 27, 1997

View of the Jarrell tornado as it obliterates homes on Double Creek Drive. The slow moving storm caused the most intense wind damage ever documented.

□ On May 27, 1997, a tornado of unparalleled violence touched down in the hills of Central Texas. The storm was spawned from a rapidly developing supercell that drifted slowly to the southwest, the opposite direction of most severe thunderstorms. Initially, the thread-like funnel caused little damage as it followed the I-35 towards the small town of Jarrell.

Unexpectedly, the tornado entered a period of explosive intensification several miles north of Jarrell. In less than two minutes, the narrow funnel expanded into a massive, violently rotating wedge tornado. Large sections of pavement were torn from county roads as the storm made a shift to the west-southwest, sparing the center of Jarrell. Homes that lined County Road 305 and Double Creek Drive, however, lay directly in the storm’s path. Good visibility and excellent warning meant that all the area’s residents were well aware of the tornado, but interior rooms in well-constructed homes provided no protection. Every home in the tornado’s path was swept cleanly away, killing entire families. In the homes where the fatalities occurred, there were only three survivors – all on the far northern edge of the tornado’s damage path. The 0% survival rate for those above ground in the core of worst damage is unique to the Jarrell event.

The damage in the Double Creek area was the most intense ever surveyed. The thick pasture grass that once covered the area was ripped completely from the ground, along with more than one foot of soil. The sheds, fences and trees that populated the neighborhood were also removed, leaving nothing but fields of empty mud. All of the pavement in the worst affected areas was scoured, and every telephone pole in the core damage path was sheared inches above ground level. Surveyors also documented perhaps the most extreme instance of debris granulation ever recorded. All of the destroyed structures, trees and utility poles were pulverized into tiny pieces, quite literally leaving nothing left for emergency crews to sift through. The bodies of the victims were thrown long distances, many more than a quarter mile, and were nearly impossible to identify. Additionally, more than a dozen vehicles known to have been in the Double Creek area were removed without a trace (Grazulis, 2003).

Debate exists over the nature of the Jarrell damage. Post-storm surveys were challenging due to the complete lack of debris, but some of the homes were determined to have been well-constructed (NOAA, 2003). Additionally, one of the destroyed homes where three fatalities occurred had thick stone walls 24-inches thick (NBC, 1997). Even so, many believe that the slow movement of the Jarrell tornado, which averaged 8mph, was primarily responsible for the severity of the damage. While the tornado’s slow pace surely contributed to its astounding violence, the nature of the damage was highly indicative of F5 winds.

Whether it had the highest winds or not, the damage from the Jarrell tornado was unparalleled and worthy of the #1 spot on any list of tornado damage severity. A more thorough examination of the Jarrell tornado, along with damage pictures, can be found here.

Catastrophic damage to frame homes following the Jarrell tornado. Thick pasture grass, trees, property fences, pavement and backyard gardens once covered the muddy landscape. Most of the debris, including more than a dozen vehicles, was splintered into indiscernibly small pieces and never recovered.

Three views of damage in the vicinity of Double Creek Drive. The image at left was taken on the fringe of the damage swath and serves as a control shot for the original appearance of the area. The image at center shows severe grass scouring at the edge of the main damage path, and the image at right shows the complete removal of all vegetation in the worst affected area. (J u n g a / flickr.com)

Extreme damage to properties on County Road 305. A woman and her teenage son were killed in a large home that once rested on the bare foundation at right.

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□ Potential top tornadoes not on the list include:
Chandler, MN – June 16, 1992 – Caused extreme vegetation damage, but only one death.
Hesston, KS – March 13, 1990 – Scoured vegetation and swept homes completely away.
Goessel, KS – March 13, 1990 – Media reports say Fujita estimated 300mph+ winds.
Girard, Kansas – May 4, 2003 – Severe ground scouring, chasers believed it was an F5.
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Click to see:
Part II
Part III
Part IV
The Strongest Tornadoes Pre-1970