2011 El Reno–Piedmont tornado

2011 EF5 tornado in Oklahoma the 2011 EF5 tornado the record-breaking 2.6 mile wide 2013 EF3 tornado 2013 El Reno tornado the 2019 EF3 tornado Tornado outbreak of May 25–30, 2019#El Reno, Oklahoma March 2023 March 2023 infobox 1/2 300 2011 El Reno-Piedmont, Oklahoma EF5 tornado.png 2011 El Reno-Piedmont tornado radar.png 2011 El Reno–Piedmont tornado NWS map.jpg HWY 81 N of El Reno OK EF4 Farmhouse.jpg May_24_2011_El_Reno_tornado_track_satellite_image.png The tornado's swirling velocity and reflectivity signatures on radar. Counterclockwise from top: The EF5 tornado seen near peak intensity north of El Reno; track of the tornado’s path, marked as B2, with a satellite tornado marked as B3; MODIS satellite imagery on May 26 of a scar left behind by the tornado; EF4 damage to a farmhouse north of El Reno; NEXRAD doppler radar of the tornado, marked by a debris ball (white pixels), just west of Piedmont May 24, 2011, 3:51 p.m. CDT (UTC–05:00) May 24, 2011, 5:35 p.m. CDT (UTC–05:00) 1 hour, 44 minutes atl EF5 1760 yd mi km 2 63.1 mi km Official intensity: >210 mph km/h on Radar-estimated: 295 mph km/h on(Fourth-highest worldwide; as measured by RaXPol Doppler weather radar analysis)Lyza Anthony W. Flournoy Matthew D. Alford A. Addison Comparison of Tornado Damage Characteristics to Low-Altitude WSR-88D Radar Observations and Implications for Tornado Intensity Estimation Monthly Weather Review 19 March 2024 10.1175/MWR-D-23-0242.1 https://journals.ametsoc.org/view/journals/mwre/aop/MWR-D-23-0242.1/MWR-D-23-0242.1.xml 19 March 2024 National Oceanic and Atmospheric Administration and University of Oklahoma via the American Meteorological Society 9 181 Unknown 2011 Canadian, Kingfisher and Logan Counties; specifically near Calumet, El Reno, Piedmont and Guthrie, Oklahoma, United States tornado outbreak sequence of May 21–26, 2011 and tornadoes of 2011 During the late-afternoon hours of May 24, 2011, a large, long-tracked and exceptionally violent EF5 tornado, commonly known as the El Reno–Piedmont tornado, impacted areas near or within the communities of El Reno, Piedmont, and Guthrie, killing nine people and injuring 181 others. After producing incredible damage in several locations along a path of more than 60 mi km out, the tornado was given a rating of EF5 on the Enhanced Fujita scale, with peak wind speeds in excess of 210 mph km/h on, although a mobile Doppler radar found that the tornado possessed wind speeds of up to 295 mph km/h on. The tornado was the first F5/EF5 tornado to occur in Oklahoma since May 3, 1999, when an F5 tornado devastated areas in and around the Oklahoma City metropolitan area.National Weather Service Storm Events Database; Event Types: Tornado F5/EF5 only in Oklahoma; January 1, 1999 - December 31, 2026 https://www.ncei.noaa.gov/stormevents/listevents.jsp?eventType=%28C%29+Tornado&beginDate_mm=01&beginDate_dd=01&beginDate_yyyy=1999&endDate_mm=12&endDate_dd=31&endDate_yyyy=2026&county=ALL&hailfilter=0.00&tornfilter=5&windfilter=000&sort=DT&submitbutton=Search&statefips=40%2COKLAHOMA National Centers for Environmental Information May 9, 2026 The tornado touched down in southwestern Canadian County and quickly became violent, debarking numerous trees as it passed through areas several miles southwest of Calumet. As it approached and crossed I-40 west of El Reno, it reached its maximum intensity. A nearby 20,000 lb kg 2 on oil tanker truck that was parked at an oil production site near the interstate was thrown approximately in 1 mi km into a wooded gully.Gardner, Jim May 24, 2011 Tornado Hits Producing Location-Oklahoma motion picture https://www.youtube.com/watch?v=7dfzLj3u5n4&NR=1 January 20, 2014 KFOR Oklahoma A farmhouse was destroyed along I-40.https://ams.confex.com/ams/92Annual/webprogram/Paper201297.html Overview of the 24 May 2011 Tornado Outbreak Ortega Kiel January 25, 2012 ams.confex.com American Meteorological Society 31 August 2014 3 September 2014 https://web.archive.org/web/20140903065712/https://ams.confex.com/ams/92Annual/webprogram/Paper201297.html live At the nearby Cactus-117 oil rig site, a 1,900,000 lb kg 2 on oil derrick was blown over and rolled three times. The tornado remained very violent as it passed north of El Reno and continued northeast, producing EF3 to EF4 damage in rural areas. The tornado then re-intensified and passed northwest of Piedmont at high-end EF4 intensity, leveling multiple homes and causing additional fatalities. Moving into Kingfisher County and Logan County south of Cashion, the tornado fluctuated several times between EF2 and EF3 intensity, causing varying degrees of damage. Afterwards, the tornado then rapidly weakened, causing EF0 to EF1 damage along the north side of Guthrie before dissipating. 2011 was a prolific year for tornadoes and tornado-associated fatalities, with multiple destructive outbreaks. The El Reno–Piedmont tornado occurred during an outbreak across Oklahoma and the Great Plains that produced multiple strong to violent tornadoes near the Oklahoma City metropolitan area on May 24, and was itself part of a tornado outbreak sequence spanning from May 21–26. The Oklahoma storms came just two days after a devastating EF5 tornado struck Joplin, Missouri, which killed 158 people and became the costliest tornado in U.S. history. Additionally, the city of El Reno had and has infamously been the site of other intense tornadoes. On May 31, 2013, a tornado just south of the town became the largest ever recorded, with a width of 2.6 mi km and radar-indicated wind speeds in excess of 296 mph km/h on. The massive multiple-vortex tornado killed eight people, including three storm chasers, and received a damage rating of EF3. In the late evening hours of May 25, 2019, a brief low-end EF3 tornado that spawned from an intense squall line struck just southeast of El Reno, killing two people and injuring dozens of others.Fernandez Manny Fenwick Ben 2019-05-26 'There I Was, Flying Across the Room': Tornado Leaves an Oklahoma Town Shaken en-US The New York Times https://www.nytimes.com/2019/05/26/us/oklahoma-el-reno-tornado.html 2023-03-02 0362-4331 March 2, 2023 https://web.archive.org/web/20230302160728/https://www.nytimes.com/2019/05/26/us/oklahoma-el-reno-tornado.html live Meteorological synopsis Tornado outbreak sequence of May 21–26, 2011 Setup Early on May 24, a strong upper-level trough (an elongated region of low atmospheric pressure aloft) advanced towards the Great Plains out of the southwestern United States and took on a negative tilt, becoming oriented northwest to southeast.Tanamachi Robin L. Heinselman Pamela L. Wicker Louis J. 2015-06-01 Impacts of a Storm Merger on the 24 May 2011 El Reno, Oklahoma, Tornadic Supercell Weather and Forecasting EN 30 3 501–524 10.1175/WAF-D-14-00164.1 1520-0434 free 504 At the same time, southerly flow brought moisture north over Texas and the southern Great Plains, allowing dew points in Central Oklahoma to reach 18–21 C F on.504–505 This moisture, with temperatures in the mid 80 F C on range, allowed for ample convective available potential energy (or CAPE, a measure of atmospheric instability); values reached 2500–4000 J/kg. Mid-level lapse rates were nearly dry adiabatic.Ortega Kiel L. Bluestein Howard B. Burgess Donald W. Garfield Gabriel S. 3 January 25, 2012 Overview of the May 24 2011 Tornado Outbreak https://ams.confex.com/ams/92Annual/webprogram/Paper201297.html 92nd American Meteorological Society Annual Meeting, Special Symposium on the Tornado Disasters of 2011 https://web.archive.org/web/20230207012208/https://ams.confex.com/ams/92Annual/webprogram/Paper201297.html February 7, 2023 February 10, 2023 American Meteorological Society2504–505 In the late morning, a shortwave embedded within the main longwave trough advanced more rapidly, pushing the dryline into western Oklahoma, where it met the already-present moisture.504–505 The shortwave's advance also brought strong wind shear and "incredibly high" storm-relative helicity values of more than 500 m2s−2. The convergence of all these factors promised the development of intense convective thunderstorms.2 Forecast vertical NWS SPC May 24, 2011 1630Z UTC Day 1 Convective Outlook Categorical Graphic.png The National Weather Service Storm Prediction Center's Day 1 Convective Outlook for May 24, showing the Categorical Graphic NWS SPC May 24, 2011 1630Z UTC Day 1 Convective Outlook Probabilistic Tornado Graphic.png The probability of a tornado within 25 miles of a point (cross-hatched area: 10% or greater probability of EF2+ tornadoes) The National Weather Service Storm Prediction Center outlined a high-risk area for severe weather over central Oklahoma on this map. This version of the map shows a 45% probability of a tornado within 25 miles of a given point in the highest risk area, and a 10% chance of a significant tornado. This risk was anticipated by the National Weather Service's Storm Prediction Center (SPC), and its local forecast office in Norman, Oklahoma. The Storm Prediction Center's outlooks for severe weather culminated in a high risk area being delineated over the Great Plains for May 24. Issued at 11:25 a.m. CDT, the Storm Prediction Center's convective outlook for the day highlighted the tornado risk, which included central Oklahoma inside a large region of a 45% chance of a tornado touchdown within 25 mi km of any given point, and a 10% or greater chance of a significant (EF2+) tornado within that same 25 mi km on radius.http://www.spc.noaa.gov/products/outlook/archive/2011/day1otlk_20110524_1630.html Storm Prediction Center May 24, 2011 1630 UTC Day 1 Convective Outlook Hart John A. Grams Jeremy S. May 24, 2011 NOAA/NWS Storm Prediction Center (SPC) Norman, Oklahoma February 13, 2023 https://web.archive.org/web/20190110192038/https://www.spc.noaa.gov/products/outlook/archive/2011/day1otlk_20110524_1630.html January 10, 2019 live ...AN INTENSE OUTBREAK OF TORNADOES AND WIDESPREAD SEVERE THUNDERSTORMS IS EXPECTED LATER TODAY OVER PORTIONS OF KS/OK/TX... ...WITH ALL CONDITIONS FAVORING THE POTENTIAL FOR LONG-TRACKED STRONG/VIOLENT TORNADOES AND VERY LARGE HAIL OVER PORTIONS OF NORTH TX...CENTRAL OK...AND CENTRAL KS. NWS Storm Prediction Center (SPC) May 24, 2011 1630 UTC Day 1 Convective Outlook font-family:courier; true At 12:50 p.m., the Storm Prediction Center issued a particularly dangerous situation (PDS) tornado watch, to remain in effect until 10:00 p.m., for most of central Oklahoma extending from the state border with Kansas down through the Oklahoma City metropolitan area and into northern Texas. The text of the tornado watch again warned of the possible development of "destructive tornadoes... ...some of which could be long-tracked and strong to violent."http://www.spc.noaa.gov/products/watch/2011/ww0356.html Particularly Dangerous Situation (PDS) Tornado Watch 356 Mead Corey M. May 24, 2011 National Oceanic and Atmospheric Administration Norman, Oklahoma May 24, 2011 https://web.archive.org/web/20140903142931/http://www.spc.noaa.gov/products/watch/2011/ww0356.html September 3, 2014 live Storm Prediction Center Initiation Thunderstorms began to develop before 2:00 p.m. in a north–south oriented line just east of the dryline where the capping inversion was weakest,505 including near Altus and Lawton in southwest Oklahoma. The tightly spaced storm cells rapidly developed classic supercell characteristics as they moved northeast. The storm that produced the El Reno–Piedmont tornado formed approximately 150 km mi flip west-southwest of Oklahoma City.505 Tornado summary Background The supercell that eventually generated the El Reno–Piedmont tornado first produced a tornado in Caddo County, Oklahoma, which tracked from west of the town of Lookeba to just northeast of it. The Lookeba tornado developed at 3:31 p.m. and persisted for approximately 16 minutes, traveling 9 mi km in and destroying multiple structures. The 800 yd m mid -wide tornado earned a damage rating of EF3. As the Lookeba tornado moved northeast towards the Caddo/Canadian county border, between 3:40 and 3:42 p.m. the supercell's mesocyclone broadened and weakened slightly; this was followed by the development of a second mesocyclone from the original to the east-southeast between 3:42 and 3:44 p.m.2689 This marked the start of the decay of the Lookeba tornado, which fully dissipated by 3:47 p.m.2690 Over the next several minutes the original western mesocyclone dwindled as the newer mesocyclone coalesced, and the radar detection of a bounded weak echo region within the storm indicated that its updraft intensified during this period.2691–2692 Formation, peak intensity and Interstate 40 thumb|right|Track of the EF5 tornado throughout Canadian, Kingfisher and Logan Counties. Parameters #bee8ff Other (Miscellaneous) #00ffc5 EF0 / 65–85 mph #55ff00 EF1 / 86–110 mph #ffff00 EF2 / 111–135 mph #e69800 EF3 / 136–165 mph #e60000 EF4 / 166–200 mph #7f255d EF5 / 201+ mph (No damage points) end|alt=NOAA Damage Assessment Toolkit map and legend of the tornado track. The indicated triangle colors are corresponding to the appropriate issued damage the tornado produced The El Reno–Piedmont tornado formed in western Canadian County at 3:51 p.m., as determined by mobile radar data. Over the next four minutes, the tornado's condensation funnel extending from a low-hanging wall cloud broadened, causing the tornado to take on a large 'wedge' appearance.Houser Jana Lesak Bluestein Howard B. Snyder Jeffrey C. 2015-07-01 Rapid-Scan, Polarimetric, Doppler Radar Observations of Tornadogenesis and Tornado Dissipation in a Tornadic Supercell: The "El Reno, Oklahoma" Storm of 24 May 2011 Monthly Weather Review EN 143 7 2685–2710 10.1175/MWR-D-14-00253.1 1520-0493 free 2696 It intensified quickly as it moved northeast, debarking and destroying many trees at EF5 intensity.10 During this period, the storm 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 2 mi km in south of I-40, captured the "first polarimetric, rapid-scan, mobile Doppler weather radar dataset of an EF-5 tornado."3 Radar analysis Disagreements on the intensity of tornadoes left|thumb|The RaXPol mobile Doppler radar, shown here scanning a severe thunderstorm in Oklahoma in 2013|alt=A large radar dish mounted on a white pickup truck scans the dark, cloudy sky. As the tornado moved towards I-40 to the southeast of the RaXPol radar and was peaking in intensity, 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 mph on, measured 60-70 m ft flip above the ground at 4:00:26 p.m.;Houser Jana Lesak Bluestein Howard B. Snyder Jeffrey C. 2016-11-01 A Finescale Radar Examination of the Tornadic Debris Signature and Weak-Echo Reflectivity Band Associated with a Large, Violent Tornado Monthly Weather Review EN 144 11 4101–4130 10.1175/MWR-D-15-0408.1 1520-0493 free 410332 however, the maximum velocity was later reported as having been 132.1 m/s mph on measured ~22 m ft out flip "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.Snyder Jeffrey C. Bluestein Howard B. 2014-08-01 Some Considerations for the Use of High-Resolution Mobile Radar Data in Tornado Intensity Determination Weather and Forecasting EN 29 4 799–827 10.1175/WAF-D-14-00026.1 1520-0434 free 811 Maximum radial velocities were also reported to have remained "greater than 120.0 m/s mph on for several minutes."2 Additionally, multiple consecutive radar scans were averaged to yield an estimated 2-second average radial velocity of 118.4 m/s mph on and an estimated 4-second average velocity of 110.8 m/s mph on. This was reported as "likely to be an underestimate of the true 2- and 4-s average wind speeds."3b The instantaneous velocity readings taken are not directly equivalent to the three-second gust at 10 m ft flip 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 mph on were recorded in both the 1999 Bridge Creek–Moore tornadoBluestein Howard B. Snyder Jeffrey C. Houser Jana B. Pazmany Andrew L. June 28, 2012 Rapidscan, polarimetric, mobile Doppler radar observations at Xband of an EF5 tornado in Oklahoma on 24 May 2011 http://www.meteo.fr/cic/meetings/2012/ERAD/extended_abs/RCS_041_ext_abs.pdf The Seventh European Conference on Radar in Meteorology and Hydrology https://web.archive.org/web/20220301122259/http://www.meteo.fr/cic/meetings/2012/ERAD/extended_abs/RCS_041_ext_abs.pdf March 1, 2022 Météo France and a sub-vortex within the 2013 El Reno tornado.Bluestein Howard B. Thiem Kyle J. Snyder Jeffrey C. Houser Jana B. 2018-08-01 The Multiple-Vortex Structure of the El Reno, Oklahoma, Tornado on 31 May 2013 Monthly Weather Review EN 146 8 2483–2502 10.1175/MWR-D-18-0073.1 1520-0493 free 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.Kosiba Karen Wurman Joshua 2023-02-24 The strongest winds in tornadoes are very near the ground Communications Earth & Environment en 4 1 1–6 10.1038/s43247-023-00716-6 2662-4435 free 804 After the detection of the wind speeds, the quality of the data degraded until collection ceased altogether at 4:16 p.m., as the tornado turned to the east-northeast and towards I-40 where it would produce its most intense damage.4103 El Reno outskirts When the tornado crossed I-40, the RaXPol radar 10 km mi flip away was still recording maximum radial velocities over 100 m/s mph on, 170 m yd out flip above the ground.2 There, the tornado struck multiple people in their cars at EF3 strength.10 Three people—Terry Peoples, 50; Don Wesley Krug, 71; and Joan Krug, 67Ellis Randy May 29, 2011 Fulfilling deadly predictions 16A (archive), 17A The Oklahoman https://www.newspapers.com/clip/119348814/fulfilling-deadly-predictions-page-16a/ live February 20, 2023 https://web.archive.org/web/20230221035424/https://www.newspapers.com/clip/119352222/fulfilling-deadly-predictions-page-17a/ February 21, 2023 Newspapers.com—were killed in two separate full-size pickup trucks, which were hurled thousands of feet from the road. Their bodies were found more than 300 yd m north of the interstate, outside their vehicles, stripped of clothing, and rendered "unrecognizable", according to responding state troopers.May 25, 2011 Bodies found near I-40, bringing death toll to 9 Muskogee Phoenix Associated Press https://www.muskogeephoenix.com/archives/bodies-found-near-i-40-bringing-death-toll-to-9/article_71ac5f5d-2496-5744-9229-487d56606cf7.html live February 10, 2023 https://web.archive.org/web/20230209190726/https://www.muskogeephoenix.com/archives/bodies-found-near-i-40-bringing-death-toll-to-9/article_71ac5f5d-2496-5744-9229-487d56606cf7.html February 9, 2023 Several others were injured here as their vehicles were battered and overturned,O’Connor Anahad 2011-05-25 At Least 14 People Are Killed in Storms in 3 States en-US The New York Times https://www.nytimes.com/2011/05/26/us/26storm.html 2023-02-09 0362-4331 February 9, 2023 https://web.archive.org/web/20230209190710/https://www.nytimes.com/2011/05/26/us/26storm.html live including a truck driver whose semi truck was flipped. The interstate was left littered with pieces of cars.Dean Bryan May 25, 2011 Twisters' deadly fury: At least 5 dead, dozens injured after tornadoes sweep across state 1A (archive), 4A The Oklahoman https://www.newspapers.com/clip/119108412/twisters-deadly-fury-at-least-5-dead/ live February 19, 2023 https://web.archive.org/web/20230219181729/https://www.newspapers.com/clip/119108683/twisters-deadly-fury-at-least-5-dead/ February 19, 2023 Newspapers.com Two more fatalities in cars occurred just northeast of the interstate.February 24, 2011 Violent Tornadoes (F4/F5/EF-4/EF-5) in Oklahoma (1950–Present) https://www.weather.gov/oun/tornadodata-ok-violent live https://web.archive.org/web/20200918090340/https://www.weather.gov/oun/tornadodata-ok-violent September 18, 2020 February 23, 2023 National Weather Service Norman, Oklahoma NOAA According to the National Weather Service, the tornado is believed to have caused its maximum amount of damage just after crossing I-40. thumb|Damage at the Cactus 117 oil drilling rig near El Reno, showing the mangled and overturned rig|alt=In the distance, a massive crumpled metal oil rig frame is surrounded by debris. Just after crossing US 270, the tornado struck a complex of buildings (including a scrap yard, auto repair shop, garage, and grain storage facility) at EF3 intensity.10 The repair shop, the garage, and a farmhouse were destroyed, and the grain facility was "damaged beyond repair".7 Flying debris from the salvage yard impacted a new natural gas processing plant operated by Devon Energy, but all employees present avoided injury by sheltering on-site in time.Marks Jay F. May 26, 2011 Oklahoma tornadoes: Devon Energy plant idled by damage The Oklahoman https://www.oklahoman.com/story/business/2011/05/26/oklahoma-tornadoes-devon-energy-plant-idled-by-damage/61161282007/ live February 14, 2023 https://web.archive.org/web/20220527075104/https://www.oklahoman.com/story/business/2011/05/26/oklahoma-tornadoes-devon-energy-plant-idled-by-damage/61161282007/ May 27, 2022 The damage caused a major gas leak at the plant, which was not secured until nightfall.May 25, 2011 El Reno Responds to Tornado Aftermath KWTV-DT https://www.news9.com/story/5e35b18b83eff40362becdb5/el-reno-responds-to-tornado-aftermath February 26, 2023 February 11, 2023 https://web.archive.org/web/20230211053156/https://www.news9.com/story/5e35b18b83eff40362becdb5/el-reno-responds-to-tornado-aftermath live The tornado then quickly reached EF5 intensity as it struck the Cactus 117 oil drilling rig site at the corner of the Old 66 and North Courtney Road intersection, completely destroying it.10 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 kg on of downforce.6 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.26 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 ft 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.Marshall Timothy P. (Haag Engineering Co.) Ladue James G. Ortega Kiel L. Stumpf Gregory J. (NOAA/NWS) November 7, 2012 Performance of residences and shelters in the Oklahoma tornadoes of 24 May 2011 https://ams.confex.com/ams/26SLS/webprogram/Paper211671.html 26th Conference on Severe Local Storms https://web.archive.org/web/20230210155727/https://ams.confex.com/ams/26SLS/webprogram/Paper211671.html February 10, 2023 February 10, 2023 American Meteorological Society26 The move to tie down change houses for tornado shelters at Cactus drilling rigs had come less than a year before the El Reno–Piedmont tornado, and following the storm Cactus moved to reinforce the change house roofs and position them where the rig would be less likely to topple on to them.Wilmoth Adam May 30, 2014 Reinforced shelters make oil patch safer in tornado season The Oklahoman https://www.oklahoman.com/story/business/energy-resource/2014/05/30/reinforced-shelters-make-oil-patch-safer-in-tornado-season/60822057007/ live February 10, 2023 https://web.archive.org/web/20230210165526/https://www.oklahoman.com/story/business/energy-resource/2014/05/30/reinforced-shelters-make-oil-patch-safer-in-tornado-season/60822057007/ February 10, 2023 Damage at the Cactus 117 rig amounted to $14 million.Scott Katherine February 14, 2012 12 lives saved in F5 tornado proves value of Cactus Drilling emergency plan https://drillingcontractor.org/12-lives-saved-in-f5-tornado-proves-value-of-cactus-drilling-emergency-plan-13665 live https://web.archive.org/web/20220808052525/https://drillingcontractor.org/12-lives-saved-in-f5-tornado-proves-value-of-cactus-drilling-emergency-plan-13665 August 8, 2022 February 10, 2023 Drilling Contractor ...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 PM CDT FOR NORTHEASTERN CANADIAN COUNTY... AT 431 PM CDT...A LARGE...VIOLENT TORNADO WAS LOCATED IN THE NORTHERN PARTS OF EL RENO...MOVING EAST-NORTHEAST AT 30 MPH. PERSONS IN EL RENO...PIEDMONT...AND NORTHERN YUKON NEED TO BE TAKING SHELTER! THIS IS A VERY DANGEROUS SITUATION! LOCATIONS IN THE WARNING INCLUDE CONCHO...EL RENO...NORTHWESTERN OKLAHOMA CITY...OKARCHE...PIEDMONT AND RICHLAND. $$ National Weather Service Norman, Oklahoma Severe Weather Statement, 4:32 p.m. CDT, May 24, 2011 left 30% thumbnail|A debarked tree just north El Reno with various debris piled at its base and severe ground scouring in the foreground. The vehicle in background is speared to another tree. After destroying the Cactus rig, the tornado continued moving east-northeast. The tornado then passed between Fort Reno and an Oklahoma Mesonet site, which recorded a sharp drop in atmospheric pressure, as well as a one-minute average wind speed of 115 mph km/h on and a maximum wind gust of 151 mph km/h on at 4:21 p.m. The gust was the highest wind speed ever recorded by the Oklahoma Mesonet.McManus Gary Oklahoma Mesonet Site Records Tornadic Winds https://www.mesonet.org/index.php/news/article/oklahoma_mesonet_site_records_tornadic_winds dead https://web.archive.org/web/20230209190723/https://www.mesonet.org/index.php/news/article/oklahoma_mesonet_site_records_tornadic_winds February 9, 2023 February 9, 2023 Mesonet.org The site sustained only minor damage, the tornado likely having passed several hundred yards from it.Fiebrich Chris May 28, 2011 Oklahoma Mesonet Station Stands Tall in EF-4 Tornado https://blog.ametsoc.org/2011/05/28/oklahoma-mesonet-station-stands-tall-in-ef-4-tornado/ live https://web.archive.org/web/20230213185917/https://blog.ametsoc.org/2011/05/28/oklahoma-mesonet-station-stands-tall-in-ef-4-tornado/ February 13, 2023 February 13, 2023 The Front Page American Meteorological Society Fort Reno sustained some structural damage. North of El Reno along US 81, two homes were struck: the first one was leveled at EF4 intensity and another one was swept completely away with debris being absent.ArcGIS Web Application https://apps.dat.noaa.gov/StormDamage/DamageViewer/ apps.dat.noaa.gov 8 October 2025Unknown May 24, 2011 El Reno Tornado Raw Rescue Video motion picture https://www.youtube.com/watch?v=fK7_mnc4gAQ January 20, 2014 SurvuM Oklahoma Satellite tornado observations Leaving the environs of El Reno, the tornado then tracked through miles of mainly agricultural land. Widespread EF3 damage, pockmarked with areas of EF4 damage, was found between the towns of El Reno and Piedmont. During the tornado's journey between El Reno and Piedmont, at least two satellite tornadoes were present at different times. The first was only recognized after the fact using radar data. That data shows the El Reno–Piedmont tornado and a separate cyclonic tornado, originating from the same mesocyclone, rotating in a counterclockwise fashion about a single common center (in a demonstration of the Fujiwhara effect) for several minutes, before merging at approximately 4:35 p.m.French Michael M. Skinner Patrick S. Wicker Louis J. Bluestein Howard B. 2015-08-01 Documenting a Rare Tornado Merger Observed in the 24 May 2011 El Reno–Piedmont, Oklahoma, Supercell Monthly Weather Review EN 143 8 3025–3043 10.1175/MWR-D-14-00349.1 1520-0493 free 3033 The second satellite came just minutes later. At 4:37 p.m., a Storm Prediction Center employee observed this separate vortex several miles northwest of Richland as it rotated around the main tornado for two minutes—only 50 yd m wide or so, it produced no damage that could be distinguished from that of the larger tornado, and was thus assigned a damage rating of EF0. Piedmont to Guthrie regions thumb|Debris from a house northeast of Piedmont struck by the tornado—this damage was given an EF4 rating|alt=Concrete slab foundations of homes are covered in shredded debris, with a dark and cloudy sky behind them. As the tornado neared Piedmont, it produced widespread EF4 damage north and west of the town. About 5 km mi in flip north of Piedmont, the tornado leveled ten homes on Northridge Lane and rolled or lofted vehicles into nearby fields. However, surveys found that nails had been used to help fasten the walls to their concrete slab foundations, which failed and left broken portions of the slabs where they had been driven in. The tornado destroyed two more houses on Axeman Street, 6.5 km mi flip 1 in northeast of Piedmont. A Chevrolet Avalanche parked in the garage of one of the residences was hurled 710 yd m to the northeast and into a thicket of trees in a ravine, which were debarked and relieved of their branches. The Chevrolet's engine block and axles were found nearby, ripped from the car. The damage here was assigned an EF4 rating.2–3 In the subdivision of Falcon Lake, 8 km mi 0 out flip on northeast of Piedmont and on the border of Canadian and Kingfisher Counties, multiple homes again had the walls removed from their concrete slab foundations. Vehicles were tossed into an adjacent lake. Two children (aged one and three years old) were killed in their home, which lacked a storm shelter.4 All told, the tornado destroyed 88 homes in the Piedmont area.Medley Robert May 19, 2021 A day of horror from the sky Piedmont-Surrey Gazette https://piedmontnewsonline.com/index.php/2021/05/19/a-day-of-horror-from-the-sky/ live February 14, 2023 https://web.archive.org/web/20210520034241/https://piedmontnewsonline.com/index.php/2021/05/19/a-day-of-horror-from-the-sky/ May 20, 2021 Weakening and dissipation The tornado's intensity diminished somewhat as the tornado crossed into Kingfisher and Logan Counties,5 having already traveled just shy of 40 mi km on its track through Canadian County. EF2 and EF3 damage still occurred as the tornado damaged houses, destroyed multiple mobile homes,5 and collapsed high-voltage transmission towers, while continuing to debark trees to the point where only stumps remained.Storm Events Database: Segment #3 of the Calumet-El Reno-Piedmont-Guthrie tornado https://www.ncei.noaa.gov/access/storm-events-database/event-details/315848 live https://web.archive.org/web/20230129044446/https://www.ncei.noaa.gov/access/storm-events-database/event-details/315848 January 29, 2023 March 1, 2023 National Centers for Environmental Information NOAA The tornado killed two more people—caught outside without shelter—near the community of Cashion.5 Along SH-74, the tornado destroyed three homes and an airplane hangar. The tornado approached Guthrie, but moved northwest of the town, which avoided a direct hit. The tornado finally dissipated northeast of Guthrie, producing only minor tree damage there. The tornado's parent supercell went on to produce another tornado south of the community of Stillwater, which earned a damage rating of EF2. Analysis The tornado reached a maximum width of 1760 yd m, or over a mile wide at its peak. Its damage path was 63 mi km long. The tornado traversed this distance over the course of about one hour and 44 minutes, implying an average forward speed of approximately 36 mph km/h out.The May 24, 2011 Tornado Outbreak in Oklahoma https://www.weather.gov/oun/events-20110524 live https://web.archive.org/web/20221211150924/https://www.weather.gov/oun/events-20110524 December 11, 2022 February 9, 2022 National Weather Service NOAA On June 1, 2011, National Weather Service officials upgraded the tornado's preliminary EF4 rating to EF5 based on a combination of the damage to the Cactus 117 drilling rig site, the complete destruction of other buildings in the rig's vicinity, tossed vehicles, and the mobile Doppler radar data.7 In the end, 22 tornadoes occurred in central Oklahoma during the El Reno–Piedmont tornado's parent outbreak. In the Oklahoma City area, five main supercells produced 12 tornadoes,1 three of them violent (EF4+). The El Reno–Piedmont tornado was the strongest of them all.1 The El Reno–Piedmont tornado became one of only 59 tornadoes ever rated F5 or EF5 to date, and one of only ten tornadoes to receive an EF5 rating since the advent of the Enhanced Fujita scale in 2007. It was the first tornado in Oklahoma to receive an EF5 rating, and the only one until the 2013 Moore tornado. Impacts Following the tornado, first responders in Canadian County scoured the 10-20 sqmi km2 out on debris path in the corridor west of El Reno near the interstate. Three emergency operations centers were established in Canadian County near Piedmont, El Reno, and I-40. Casualties The El Reno–Piedmont tornado killed nine people and injured 181, making it responsible for the majority of the casualties caused by the entire outbreak (in which 11 died and 293 were injured).2 Of that total, seven deaths and 112 injuries occurred in Canadian County, 46 injuries occurred in Kingfisher County,Storm Events Database: Segment #2 of Calumet-El Reno-Piedmont-Guthrie tornado https://www.ncei.noaa.gov/access/storm-events-database/event-details/315839 live https://web.archive.org/web/20230129044444/https://www.ncei.noaa.gov/access/storm-events-database/event-details/315839 January 29, 2023 March 1, 2023 National Centers for Environmental Information NOAA and two deaths and 23 injuries occurred in Logan County. Three children with critical injuries in Piedmont numbered among the casualties in Canadian County. In an overview of the outbreak in a paper presented at the annual American Meteorological Society conference, National Weather Service authors speculated that the relatively low number of fatalities during the outbreak (which involved three violent tornadoes near a major metropolitan area) was due in part due to "the incredible reaction of the community to not only watches and warnings, but also to the forecast of severe weather" on May 24.2 Damage The Devon Energy natural gas plant near El Reno was forced offline for several weeks as the company assessed and repaired the $140 million facility. Though the amount of $14 million was given as the cost of damage to the Cactus 117 drilling rig site in news reports, a detailed monetary damage estimate by NWS/NOAA for the El Reno–Piedmont tornado was not made available. The only government assessment of damages appears in the tornado's entry in NOAA's NCEI Storm Events Database, which predicted that the total was "probably going to be well in the tens of millions".Storm Events Database: Segment #1 of the Calumet-El Reno-Piedmont-Guthrie tornado https://www.ncei.noaa.gov/access/storm-events-database/event-details/315837 live https://web.archive.org/web/20230129044442/https://www.ncei.noaa.gov/access/storm-events-database/event-details/315837 January 29, 2023 March 1, 2023 National Centers for Environmental Information NOAA Meanwhile, insurance officials reported an estimated $200–300 million in total private property insured losses from the Oklahoma portion of the tornado outbreak.Goodwin Brandon Kelley Ann June 8, 2011 Oklahoma tornado damage slamming cities' budgets The Oklahoman https://www.oklahoman.com/story/weather/2011/06/08/oklahoma-tornado-damage-slamming-cities-budgets/61158232007/ live February 14, 2023 https://web.archive.org/web/20230214143843/https://www.oklahoman.com/story/weather/2011/06/08/oklahoma-tornado-damage-slamming-cities-budgets/61158232007/ February 14, 2023 The city of Piedmont paid $230,380 for debris removal, 75% of which was reimbursed by FEMA.Felder Ben January 19, 2012 FEMA reimbursement on its way, more recovery money headed to Oklahoma Piedmont Today Piedmont-Surrey Gazette http://www.piedmonttoday.com/city/fema-reimbursement-on-its-way-more-recovery-money-headed-to-oklahoma/ dead March 7, 2023 https://web.archive.org/web/20120121053436/http://www.piedmonttoday.com:80/city/fema-reimbursement-on-its-way-more-recovery-money-headed-to-oklahoma/ January 21, 2012 Political response Governor of Oklahoma Mary Fallin declared a state of emergency in 68 counties on May 24, including Canadian, Kingfisher, and Logan Counties, before taking to the air to survey damage in several areas, which included Piedmont and Guthrie.May 24, 2011 Governor Mary Fallin to tour Oklahoma tornado damage News On 6 https://www.newson6.com/story/5e34fabfe0c96e774b367485/governor-mary-fallin-to-tour-oklahoma-tornado-damage live February 13, 2023 https://web.archive.org/web/20230213205356/https://www.newson6.com/story/5e34fabfe0c96e774b367485/governor-mary-fallin-to-tour-oklahoma-tornado-damage February 13, 2023 On May 29, Governor Fallin requested that the White House issue a federal major disaster declaration for seven Oklahoma counties, again including Canadian, Kingfisher, and Logan Counties.May 29, 2011 Governor Fallin Requests Federal Disaster Assistance for Individuals, Businesses in 7 Counties https://www.ok.gov/triton/modules/newsroom/newsroom_article.php?id=223&article_id=2641 https://web.archive.org/web/20230213170054/https://www.ok.gov/triton/modules/newsroom/newsroom_article.php?id=223&article_id=2641 February 13, 2023 February 14, 2023 OK.gov On June 6, President Obama approved Governor Fallin's request for federal disaster relief.June 6, 2011 White House approves Governor Fallin's request for tornado assistance https://www.ok.gov/triton/modules/newsroom/newsroom_article.php?id=223&article_id=2721 live https://web.archive.org/web/20230213170054/https://www.ok.gov/triton/modules/newsroom/newsroom_article.php?id=223&article_id=2721 February 13, 2023 February 14, 2023 OK.gov In September 2011, Governor Fallin and state emergency management officials announced the SoonerSafe-Safe Room Rebate Program, using $1 million in FEMA funds, which distributed cash rebates via a statewide drawing to reimburse up to 500 Oklahomans seeking to build storm shelters. Victims of the May 24 tornado outbreak were among those who received priority selection for the rebates.McNutt Michael September 28, 2011 Oklahoma announces safe room rebate program The Oklahoman https://www.oklahoman.com/story/news/politics/2011/09/28/oklahoma-announces-safe-room-rebate-program/61131145007/ live March 7, 2023 https://web.archive.org/web/20230307211501/https://www.oklahoman.com/story/news/politics/2011/09/28/oklahoma-announces-safe-room-rebate-program/61131145007/ March 7, 2023 See also Glossary of meteorology List of F5, EF5, and IF5 tornadoes Tornadoes of 2011 List of United States tornadoes in May 2011 References External links National Weather Service, Norman, OK - The May 24, 2011 Tornado Outbreak in Oklahoma NOAA Damage Assessment Toolkit 35.444 -98.287 title 2011-05-24 05-24, El Reno-Piedmont Tornado, El Reno-Piedmont, 05-24 Tornado, El Reno-Piedmont, 05-24 Tornado, El Reno-Piedmont, 24 2011-05-24