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□ 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.
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.
1. Jarrell, Texas – May 27, 1997
□ 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.
□ 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.
3. Kemper County (Philadelphia), Mississippi – April 27, 2011
□ 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.
4. Bridge Creek, Oklahoma – May 3rd, 1999
□ 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 that 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.
5. Bakersfield Valley, Texas – June 1, 1990
□ 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 on 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.
□ 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.