Your complete guide to tornadoes, storm science, intercept vehicles, probes, and the legendary chasers who push the boundaries of weather research.
Understanding the most violent storms on Earth
A tornado is a violently rotating column of air extending from a thunderstorm to the ground. It is the most violent of all atmospheric storms, capable of producing wind speeds exceeding 300 mph, lifting cars like toys, demolishing well-built structures, and hurling deadly debris for miles. Tornadoes vary wildly in size, from narrow ropes barely 50 yards wide to massive wedge tornadoes over a mile across.
Tornadoes most commonly form within supercell thunderstorms when warm, moist air from the Gulf of Mexico collides with cold, dry air from Canada and dry air from the Rockies. This collision creates atmospheric instability (measured as CAPE). Wind shear — changing wind speed and direction with height — causes the rising air to rotate, forming a mesocyclone. As the mesocyclone tightens and descends, a wall cloud forms and a tornado may develop.
Supercell tornadoes are the most violent, spawned by rotating thunderstorms. Landspouts form from non-supercell processes and are weaker. Waterspouts are tornadoes over water. Gustnadoes form along gust fronts. Multiple-vortex tornadoes contain smaller suction vortices within the main funnel. Wedge tornadoes are wider than they are tall and are among the most destructive.
Tornado Alley stretches from Texas to South Dakota across the central U.S. — but tornadoes occur in all 50 states. "Dixie Alley" (the southeastern U.S.) sees deadly tornadoes too, often at night. "Tornado Alley 2.0" in the Midwest and even the Northeast are seeing increasing tornado activity due to shifting climate patterns. The highest tornado frequency occurs in April through June.
Doppler radar is the primary tool for detecting tornadoes, identifying rotation (velocity couplets) within storms. Storm spotters and chasers provide ground-truth confirmation. The NWS issues tornado watches (conditions favorable) and tornado warnings (tornado imminent or detected).平均 lead time for tornado warnings is about 13 minutes. Dual-polarization radar can now detect debris signatures (TDS) confirming a tornado is on the ground.
The Tri-State Tornado (March 18, 1925) killed 695 people across Missouri, Illinois, and Indiana — the deadliest U.S. tornado ever. It traveled 219 miles in 3.5 hours. The Daulatpur-Saturia tornado (Bangladesh, 1989) killed 1,300. The 2011 Super Outbreak produced 362 tornadoes in 4 days, killing 324. The 2023 Rolling Fork, Mississippi EF4 reminded us these events remain devastatingly dangerous.
A supercell has distinct regions: the Forward Flank Downdraft (FFD) brings heavy rain and hail ahead of the storm. The Rear Flank Downdraft (RFD) wraps around the mesocyclone and can produce the tornado. The mesocyclone is the rotating updraft — visible as a lowering called a wall cloud. The Bounded Weak Echo Region (BWER) is a rain-free vault where the updraft is strongest. The hook echo on radar is the signature of the mesocyclone wrapping precipitation.
Inside a tornado, wind speeds vary dramatically. The funnel is the visible condensation funnel, but the wind field extends far beyond it. Suction vortices — small, intense sub-vortices — orbit within the main circulation and produce the most extreme damage. The corner region near the ground has the strongest winds. Pressure drops of 50-100 mb occur at the center. A tornado's damage path can range from 10 yards to over 2 miles wide.
| Rating | Wind Speed | Description | Damage Indicators |
|---|---|---|---|
| EF0 | 65 – 85 mph | Light | Broken branches, shallow root damage, gutter damage, some roof shingle damage |
| EF1 | 86 – 110 mph | Moderate | Roof surfaces peeled, mobile homes overturned, pushing cars off roads, broken windows |
| EF2 | 111 – 135 mph | Significant | Roofs torn off well-built homes, large trees snapped, trains overturned, heavy objects thrown |
| EF3 | 136 – 165 mph | Severe | Entire stories destroyed, well-built homes leveled, trains overturned, heavy cars thrown significant distances |
| EF4 | 166 – 200 mph | Devastating | Well-built homes reduced to rubble, cars thrown 100+ yards, large debris become deadly missiles, trees debarked |
| EF5 | Over 200 mph | Incredible | Strong frame houses leveled off foundations, cars thrown over 300 yards, incredible missile trajectories, steel-reinforced structures severely damaged, asphalt scoured from roads |
| Date | Tornado | Rating | Path | Deaths | Notable |
|---|---|---|---|---|---|
| Mar 18, 1925 | Tri-State Tornado | F5 | 219 mi | 695 | Deadliest U.S. tornado; MO, IL, IN |
| Apr 9, 1947 | Woodward, OK | F5 | 221 mi | 181 | Leveled 10 city blocks in Woodward |
| May 3, 1999 | Bridge Creek–Moore, OK | F5 | 38 mi | 36 | 286 mph winds — highest ever measured |
| May 3, 1999 | Mulhall, OK | F4 | 36 mi | 0 | Largest tornado ever measured by DOW (1.6 mi wide) |
| May 4, 2007 | Greensburg, KS | EF5 | 28.8 mi | 11 | Destroyed 95% of the town |
| May 22, 2011 | Joplin, MO | EF5 | 6 mi | 158 | Deadliest since 1947; $2.8B damage |
| Apr 27, 2011 | Super Outbreak | EF5 | Multiple | 324 | 362 tornadoes in 4 days across southeastern U.S. |
| May 20, 2013 | Moore, OK | EF5 | 17 mi | 24 | Plaza Towers Elementary destroyed |
| May 31, 2013 | El Reno, OK | EF3 | 16.2 mi | 8 | Widest tornado ever: 2.6 mi; killed storm chasers Tim Samaras, Paul Samaras, Carl Young |
| Apr 26, 2024 | Greenfield, IA | EF4 | 13 mi | 5 | Nearly levelled entire town; 300 mph+ winds measured by DOW |
Instrumentation that brings storm science from the field to the lab
Truck-mounted X-band Doppler radar units operated by the Center for Severe Weather Research (CSWR). DOW 6 and DOW 7 can scan inside tornadoes at close range with 75m spatial resolution. They have captured the highest-resolution velocity data of tornadoes ever recorded. The DOW fleet has been deployed in numerous major field campaigns including VORTEX, TWISTEX, and TORUS.
TOTO (Totable Tornado Observatory) was the original instrumented tornado pod developed by NSSL in the 1970s-80s. Weighing 8,000 lbs, it was designed to be placed in a tornado's direct path. In 1981, it was deployed in the path of a tornado near Union City, OK, but the tornado shifted slightly. TOTO-II was a refined, lower-profile version. Both inspired the fictional "Dorothy" in the movie Twister (1996).
Portable stations deployed in storm paths to measure temperature, humidity, pressure, and wind. These portable Automated Surface Observing Systems (ASOS) and Oklahoma Mesonet stations relay real-time data back to chase teams, building critical atmospheric profiles that validate radar data and help improve tornado prediction models.
Developed by the University of Nebraska-Lincoln, StickNet platforms are lightweight, rapidly deployable weather stations dropped in tornado paths. They measure pressure, temperature, humidity, and wind at the surface. StickNets have survived direct tornado strikes and provided groundbreaking surface-level data about tornado wind fields and pressure deficits.
Instrument packages released from NOAA P-3 and NOAA43 aircraft that descend through storms via parachute, transmitting continuous data on pressure, temperature, humidity, and wind. During Hurricane Hunter missions and VORTEX-SE campaigns, dropsondes have provided critical vertical profiles of severe storms, capturing data unreachable by ground instruments.
Storm-chasing drones like the small Uncrewed Aircraft Systems deployed by NSSL can fly directly into severe storms at low altitude, measuring wind, temperature, and pressure at levels too dangerous for crewed aircraft. During VORTEX-SE, drones successfully sampled the boundary layer in tornadic supercells, providing data that revolutionized understanding of near-surface tornado dynamics.
The Shared Mobile Atmospheric Research and Teaching Radar — a truck-mounted C-band radar system used for atmospheric research. SMART-R units can be rapidly deployed to scan developing storms, providing dual-Doppler wind analysis when combined with stationary WSR-88D radars. Used extensively in VORTEX-2 field campaigns.
The Forecast Decision Training Division deploys teams with surface observing equipment including ceilometers, disdrometers, and portable RAWS stations. These fill observational gaps between permanent NWS sites, improving mesoscale analysis and real-time warnings. Networks like the Oklahoma Mesonet (120+ stations) provide continuous data critical for severe weather forecasting.
The Tornado Aircraft for Storm Analysis and Research — expendable sensor packages designed to be dropped from aircraft directly into the path of tornadoes. Several TASAR units have survived direct tornado strikes and returned unprecedented data on the pressure, temperature, and wind profiles within the tornado vortex at multiple altitudes simultaneously.
Purpose-built machines engineered to go where no ordinary car can
A high-tech armored vehicle designed by NSSL researchers to withstand tornado-force winds while collecting in-situ data. Built on a modified truck chassis with reinforced steel armor plating, TITUS is equipped with anemometers, pressure sensors, high-speed cameras, and communication arrays. It represents the state of the art in tornado research vehicles, allowing scientists to position instruments directly in the tornado path.
The original Dominator, built in 2008 by Reed Timmer and the TVN (TornadoVideos.Net) team. Based on a modified Dodge Ram 2500, Dominator 1 was the first in the Dominator series. It featured an armored chassis, external sensor mounts, and a rear-mounted weather station. It was used in dozens of tornado intercepts across the Great Plains and became iconic through the Discovery Channel show "Storm Chasers."
The successor to Dominator 1, Dominator 2 was built in 2009 on a heavier-duty truck platform. It featured improved armor plating, a roof-mounted weather station, deployable anchor spikes to keep the vehicle planted in high winds, and a suite of high-definition cameras. Dominator 2 made several notable tornado intercepts and was featured heavily on Discovery Channel's "Storm Chasers." It could be lowered hydraulically to prevent wind from getting underneath the vehicle.
The ultimate evolution of the Dominator series, Dominator 3 is based on a Ford F-150 platform with massive hydraulic armor plates that lower from the roof to cover the windows and wheels, creating a fortress against tornado-force winds. It features an anemometer, GPS tracking, real-time data uplink, multiple HD cameras, and a rear-mounted instrument pod. Reed Timmer has driven Dominator 3 into numerous tornadoes, including EF3+ events, broadcasting live data and footage. It remains one of the most famous storm-chasing vehicles ever built.
The original TIV was built by Sean Casey for the IMAX film "Tornado Alley" (2011). Based on a heavily modified Chevy Suburban, TIV 1 was designed to take direct hits from tornadoes to capture never-before-seen IMAX footage from inside the vortex. It featured 14,000 lbs of steel armor, hydraulic stabilizers, and a turret-mounted IMAX camera. Casey famously drove TIV 1 directly into an EF2 tornado near Kismet, Kansas in 2008 — one of the most iconic tornado intercepts ever filmed. The armor held, and the footage became legendary.
The successor to TIV 1, TIV 2 was built for the Discovery Channel show "Storm Chasers." Based on a Dodge Ram 3500, it was significantly more advanced — featuring 12,000 lbs of custom armor plating, four hydraulic stabilizer legs that could be deployed to anchor the vehicle, an armored rotating turret for cameras, and reinforced windows. TIV 2 was designed to survive EF3+ tornadoes. It was featured in multiple dramatic intercepts on the show, including a terrifying encounter with a large wedge tornado in Kansas. TIV 2 remains one of the most recognizable storm-chasing vehicles in the world.
The original instrumented tornado pod developed by NSSL beginning in the late 1970s under Dr. Erik Rasmussen. TOTO was an unmanned, 8,000-lb wheeled instrumented platform designed to be placed in the direct path of a tornado. It carried pressure sensors, anemometers, temperature sensors, and hail impact gauges. In 1981, TOTO was deployed in the path of a tornado near Union City, Oklahoma — but the tornado shifted 1.5 miles south, missing the pod. Though never directly hit by a tornado, TOTO proved the concept was viable and inspired a generation of tornado probes. TOTO-II was a refined, lower-profile version.
Mobile X-band Doppler radar trucks operated by the Center for Severe Weather Research founded by Dr. Josh Wurman. DOW 6 and DOW 7 have captured the highest-resolution radar data of tornadoes ever recorded, including velocity couplets, debris signatures, and the fine-scale structure of tornado wind fields. They have been deployed in VORTEX-1, VORTEX-2, DOWTEX, and dozens of individual intercept operations. DOW data has been published in numerous peer-reviewed papers that advanced understanding of tornado dynamics.
The NOAA WP-3D Orion is a four-engine turboprop aircraft used for atmospheric research. While primarily a hurricane hunter, NOAA43 has been deployed into severe thunderstorm environments carrying tail Doppler radar, dropsonde systems, and other instruments. The P-3 can fly at low altitude through severe weather, collecting data on storm structure that ground-based instruments cannot capture. Its tail-mounted radar provides vertical cross-sections of storms revealing mesocyclone structure and tornado formation processes.
Conceptual next-generation tornado probe leveraging sensor miniaturization and autonomous deployment. Designed with hardened pressure ports, 3D ultrasonic anemometers, high-frequency accelerometers, and wireless data relay. Would be deployed automatically ahead of tornado paths using NWS radar data and real-time storm tracking algorithms, removing the need for human deployment in dangerous conditions.
The people who dedicate their lives to understanding and documenting storms
Pioneer of mobile radar research and co-developer of the Doppler on Wheels program. Led dozens of field campaigns to study tornado structure at unprecedented resolution. His work at the National Severe Storms Laboratory fundamentally advanced understanding of mesocyclone dynamics and tornado formation processes.
One of the most recognized storm chasers in the world. Known for his dramatic intercepts and the Dominator vehicle series, he has chased over 1,000 tornadoes and brought storm science to millions through television. Reed holds a Ph.D. in meteorology from the University of Oklahoma and has deployed probes in dozens of tornadoes. His live tornado intercept footage is among the most dramatic weather footage ever captured.
The face of live severe weather coverage for The Weather Channel for over 30 years. Jim has been on the ground during hurricanes, blizzards, and tornadoes, becoming one of the most trusted voices in weather broadcasting. His genuine emotional reactions during severe weather events have made him an internet phenomenon and a beloved figure in meteorology.
Groundbreaking scientist who pioneered instrument probe deployment directly in tornado paths. Founder of the Tactical Weather-Instrumented Sampling in/near Tornadoes Experiment (TWISTEX). His work on tornado pressure deficits and vortex structure revolutionized understanding. Tim, along with his son Paul Samaras and colleague Carl Young, was tragically killed in the 2013 El Reno tornado — one of the darkest days in storm chasing history. Their legacy drives continued tornado research.
One of the most prolific storm photographers in history. His website Extreme Instability features thousands of breathtaking tornado and storm images captured across the Great Plains over two decades of chasing. Mike is known for his incredible artistic eye, capturing tornadoes in perfect composition with dramatic lighting. His work has been published in National Geographic, The Weather Channel, and countless publications.
A veteran storm chaser and chief meteorologist for KFOR-TV in Oklahoma City. Known for live tornado coverage and accurate real-time reporting that has saved countless lives during severe weather events. Val's on-air calmness during violent tornadoes has made him one of the most trusted local weather figures in Oklahoma.
Creator of the Tornado Intercept Vehicles (TIV 1 and TIV 2) and director of the IMAX film "Tornado Alley." Sean spent over a decade chasing tornadoes to capture IMAX footage from inside the tornado vortex. His dedication led to the construction of purpose-built armored vehicles and some of the most dramatic tornado footage ever filmed. The Tornado Alley IMAX film remains one of the best tornado documentaries ever produced.
Creator and lead operator of the Doppler on Wheels program. Founded the Center for Severe Weather Research (CSWR). His mobile radar observations have captured the most detailed tornado velocity data in history, including the highest in-tornado wind speeds ever recorded. Dr. Wurman's research has been published in dozens of peer-reviewed journals and has fundamentally shaped our understanding of tornado structure and intensity.
Freddie McKinney is a dedicated storm chaser and documentarian known for his incredible close-range tornado footage from across the Great Plains. Based in Oklahoma, Freddie has been chasing severe storms for years, capturing some of the most vivid and up-close tornado videos ever recorded. His footage has been featured on major news networks and weather documentaries. Freddie is known for his fearless intercept style, often positioning himself in the direct path of tornadoes to capture data and video that advances both public awareness and scientific understanding of tornado behavior. He actively shares chase footage and storm science education on social media, inspiring the next generation of storm chasers.
Led the original VORTEX (Verification of the Origins of Rotation in Tornadoes Experiment) field campaigns in the 1990s and early 2000s — the largest tornado research projects ever conducted. Rasmussen designed the original TOTO probe concept and his VORTEX data provided the first comprehensive look at supercell and tornado formation processes. His work laid the foundation for modern tornado prediction and warning systems.
A legendary storm chaser with over 30 years of experience. Jeff has filmed hundreds of tornadoes and is known for his calm, methodical approach to intercepts. His footage from the 1999 Moore, Oklahoma F5 tornado and the 2013 Moore EF5 tornado are among the most significant ever captured. He has contributed footage to major documentaries and continues to chase across the Plains each spring.
A skilled meteorologist and storm chaser based in Oklahoma City. Emily has been in the field during some of the most significant tornado outbreaks in recent history. Her live on-air reporting during severe weather has earned her widespread respect. She combines rigorous scientific analysis with compelling on-camera presence, making complex weather accessible to the public.
An experienced storm chaser with decades of intercepts across the Great Plains. Jeff is known for his methodical chase strategies and extensive knowledge of storm structure. His chase logs and data have contributed to understanding of supercell evolution and tornado morphology. He remains an active and respected member of the storm chasing community.
A talented storm chaser and videographer known for capturing stunning tornado footage across Oklahoma and the southern Plains. His WXChasing social media presence features dramatic close-range tornado videos that have been viewed millions of times. Brandon's work combines artistic composition with scientific documentation, providing both awe-inspiring visuals and valuable observational data.
A dedicated storm chaser focused on collecting surface-level data during severe weather events. Connor has deployed portable weather instruments in the near-storm environment, contributing to understanding of boundary layer processes in tornadic supercells. His chase footage and data have been used in NOAA research initiatives.
Lead researcher at NSSL working on dual-polarization radar applications for tornado detection. His work on the Tornado Debris Signature (TDS) has improved tornado confirmation and warning lead times. Dr. Lyons combines radar engineering with field research to bridge the gap between remote sensing technology and real-world tornado science.
The institutions driving tornado research and public safety
Based in Norman, Oklahoma, NSSL is the premier U.S. government research lab for severe weather. It develops radar technology, forecasting tools, and field research campaigns that directly improve tornado warnings. NSSL created the Warn-on-Forecast system and co-developed dual-polarization radar now used nationwide.
Home to one of the top meteorology programs in the world, with close ties to NSSL and the National Weather Center. OU researchers lead field campaigns, develop storm-scale models, and train the next generation of severe weather forecasters and researchers.
Founded by Dr. Josh Wurman, CSWR operates the Doppler on Wheels fleet and conducts cutting-edge mobile radar research. Their DOW observations have captured the most detailed tornado wind measurements in history and published dozens of landmark papers.
The parent agency of NSSL and the National Weather Service. NOAA funds severe weather research, operates the WSR-88D radar network, issues tornado warnings through the NWS, and coordinates field campaigns like VORTEX-SE using aircraft, radar, and surface instruments.
Located in Norman, OK, SPC issues daily severe weather outlooks and tornado watches for the entire continental U.S. Their mesoscale analysis products, Convective Outlooks, and Mesoscale Discussions are essential tools used by forecasters, chasers, and emergency managers worldwide.
A major research center funded by NSF that develops atmospheric models, conducts field campaigns, and provides computing resources for severe weather research. NCAR's WRF model and community radar tools are used globally for storm forecasting and analysis.
What you need to know to stay alive
The safest place during a tornado is a basement or storm cellar. If no basement is available, go to an interior room on the lowest floor (closet, bathroom) with no windows. Mobile homes offer zero tornado protection — evacuate them immediately when a warning is issued. In a commercial building, go to the lowest interior hallway away from glass.
Cars can be tossed by tornadoes, but they offer some protection. If caught in the open: drive at right angles to the tornado's path to escape. If that's impossible, pull over, keep your seatbelt on, duck below the windows, and cover your head. Never try to outrun a tornado in the same direction it's moving. Overpasses are NOT safe shelters — they can amplify wind speeds.
Have a NOAA Weather Radio with SAME alerting. Keep your phone charged with emergency alerts enabled. Follow local NWS office forecasts on social media. When a tornado WATCH is issued, be prepared. When a WARNING is issued, take shelter immediately — you may have less than 10 minutes. Do not wait to see the tornado.
Watch for downed power lines, gas leaks, and structural damage. Do not enter damaged buildings. Help injured people if safe to do so. Report damage to local authorities. Secondary tornadoes can strike the same area. Stay away from storm drains — the tornado's pressure drop can suck objects upward. Document damage for insurance with photos.
Key milestones in the history of tornado research and chasing