I was recently looking through this sub and was blown away by the high-fidelity plots of various tornados. What made these plots so interesting to me is that they tell a much more complete story than just a single number rating on the EF scale. Also, the plots can potentially be used to answer a question I’ve always had; Which tornado is the strongest tornado in history? For the past month u/joshoctober16 and I have been collaborating to answer that question, starting with the four most infamous tornados to hit the Oklahoma City and surrounding area – the 1999 Moore F5+, 2011 El Reno EF5, 2013 Moore EF5, and 2013 El Reno EF3+.
Once the damage plots were made, the next step was summing the areas of each respective EF rated windspeed. Click Here for Areas
This data was then used to calculate the total tornadic damage produced by each tornado, or the tornado damage rating. The tornado damage rating was found by summing the product of the area by the square of the velocity of the wind speed for each respective EF rated area. The unit was adjusted so that a value of 1 is equal to 1 acre of land experiencing 100 mph winds. It is important that the damage rating is correlated to the square of velocity since the force of wind can be simplified as KV2, where K is a constant. See here how the force of wind is correlated to the square of velocity. This chart shows how much force an object would experience at each EF rating’s windspeed. See here
The plots were also analyzed to find each tornado’s rate of damage, average windspeed, EF5 Area, total area, measured width, length, average speed, ∆ area/min, the average width, equations used. Other metrics used for the comparison include official max width, duration, max measured gust windspeed, cost, and Josh’s 0-10 star rating of the most catastrophic damage created by each tornado. The following table shows the final values of the above metrics for each tornado. Table of Results
1999 Moore F5+ Highest average windspeed, largest EF5 damage area, highest windspeed measured
2011 El Reno EF5 Most total damage at the ground, largest total area, longest path, fastest forward speed, longest duration, and the most catastrophic damage
2013 Moore EF5 Highest cost
2013 El Reno Highest rate of damage, highest max official and measured widths, fastest windspeed measured, highest area change rate, highest average width
Final Strength Rankings
2011 El Reno EF5
1999 Moore F5+
2013 El Reno EF3+
2013 Moore EF5
The 2011 El Reno tornado was determined to be the strongest tornado to hit the Oklahoma City area. The primary reason was that it covered the largest area at over 26,800 acres, was the longest track at 63.8 miles, moved the fastest at an average speed of 36.5 mph, and at point created the most catastrophic damage of the four tornados. May 3rd 1999 Moore was ranked as the second strongest tornado, covering 37.8 miles at a speed of 26.7 mph, while having the highest concentration of EF5 Damage and the highest average windspeeds of the four tornados. Next is the 2013 El Reno, which covered 18,700 acres, and traveled 18.6 miles. The 2013 El Reno tornado did have the highest rate of damage due to the extreme width of the surveyed tornado damage, officially 2.6 miles. Despite being the only tornado in this comparison that isn’t rated EF5, the 2013 El Reno would have most likely produced EF5 damage had it been centered on a city like Moore. 2013 Moore, although devastating, is smaller than the other three tornados analyzed, so it ranked 4th. 2013 El Reno and May 3rd Moore tornado may have had the highest measured windspeeds, however these measurements have a degree of uncertainty, and the 2011 El Reno tornado measured winds within the margin of measurement error, so it is impossible to definitively say which of these three tornados produced the fastest winds.
Also please note there were a few points of uncertainty for each of the tornados plotted- May 3 1999 has a few blind spots in the area before it hit bridge creek. El Reno 2011 didn’t have as many aerial photos, and there is a strong possibility there was a merger of two cyclonic tornadoes, so you may consider 2011 to not be a single tornado, bumping it down on the list. The 2013 Moore path used in this analysis has the start of the tornado further southwest than the official start location since it was producing damage at the ground before the condensation funnel had fully touched down. And for El Reno 2013, there is uncertainty due to the strongest points of intensity happening over open fields.
Do you agree with our rankings?
For more information on these tornados visit u/joshoctober16’s EF5 tornado catalog- https://joshnaturaldisasterinfo.home.blog/main-page-index/
Below is a link to download the .kmz files used in this analysis. You can import the plots into google earth, they’re really cool and give a good perspective on each event. Link to .kmz files – https://github.com/tornadoguy1234/okahoma_tornados
TLDR; The 2011 El Reno Tornado was the strongest tornado to hit the Oklahoma City area.