A tornado is a rotating column of air that extends from a thunderstorm cloud to the ground. This vortex creates an environment where extreme forces are brought to bear on anything caught in its path. Understanding the physical mechanics and resulting outcomes provides a clearer picture of the challenges faced by a person caught in the storm. The unpredictable nature of a tornado means survival often depends on factors beyond individual control.
Forces of the Vortex
The initial encounter with a tornado involves the direct force of extreme wind speeds and the aerodynamic effects of the rotating air mass. An intense tornado, classified as an EF-5 on the Enhanced Fujita Scale, features estimated three-second wind gusts exceeding 200 miles per hour. These winds create immense drag forces that can lift and propel a human body, launching a person into the air or slamming them against the ground or structures.
The air within the vortex is highly turbulent, characterized by rapid, unpredictable shifts in wind direction and velocity. This turbulence subjects a person to chaotic, multidirectional forces, causing extreme disorientation and immediate physical trauma as the body is tossed and tumbled. The intense rotation is driven by an extreme pressure gradient, where the atmospheric pressure at the center of the vortex can be up to ten percent lower than the surrounding air.
A rapid drop in external pressure can have physiological effects, but these are often overshadowed by wind and debris hazards. The primary danger to a person comes from wind forces and impacts, not typically from the pressure difference causing internal rupture. However, the low-pressure core contributes significantly to destructive power by creating strong pressure differences across structures, often leading to their explosive collapse. A person is subjected to being thrown and crushed by the combination of intense, turbulent winds and sudden pressure shifts.
The Danger of Flying Debris
The greatest threat posed by a tornado is the transformation of everyday objects into high-velocity projectiles, which causes the majority of severe trauma and fatalities. Objects are rapidly accelerated and directed with devastating force. Debris is categorized into small, high-velocity items and large, lower-velocity structural components, both transferring kinetic energy upon impact.
Small, sharp objects like glass shards, nails, and wood pieces become missile-like weapons causing deep puncture wounds and impalement injuries. These high-speed impacts can penetrate soft tissue and bone, often affecting the head, neck, and chest. Larger debris, such as collapsed walls, roofing material, and vehicles, exert massive blunt force trauma. This impact trauma is similar to a severe motor vehicle crash, capable of causing immediate internal injuries and crushing skeletal structures.
The volume of airborne material means multiple, successive impacts are common, resulting in complex polytrauma where a person sustains numerous injuries simultaneously. The wind velocity ensures these impacts occur with extreme energy, overwhelming the body’s natural defenses like the skull and ribcage.
Common Injuries and Medical Outcomes
The injuries sustained in a tornado are complex, involving multiple bodily systems due to blunt force trauma and penetrating wounds. Soft tissue injuries are the most common outcome, including severe lacerations, contusions, and punctures. These injuries often require surgical cleaning and debridement due to heavy contamination from the storm environment. Cuts and scrapes are frequently found on exposed areas of the body, such as the head and limbs, as a person is struck by countless small fragments.
Orthopedic injuries, primarily fractures and joint dislocations, are a frequent consequence for tornado victims. These broken bones are often open fractures, where the bone breaks through the skin, due to high-energy impacts from flying or falling objects. The most severe medical outcomes are linked to head and internal trauma, which are the leading causes of fatality and long-term disability.
Head injuries range from severe concussions to traumatic brain injuries, frequently resulting from the skull striking debris or the ground after being thrown. Blunt force impacts to the torso can cause devastating internal injuries, including a collapsed lung, internal bleeding, and the rupture of abdominal organs such as the spleen and liver. Spinal cord damage is another serious outcome, typically resulting from the violent twisting, throwing, or crushing forces exerted by the storm.
Immediate Survival Actions
When a person is directly in the path of an imminent tornado, immediate action is necessary. The primary goal is to seek the lowest point possible and place layers of protection between the body and the outside world. The safest location in any structure is a basement, a storm cellar, or a small, interior room on the lowest floor, away from exterior walls and windows.
If shelter inside a sturdy building is unavailable, and a person is caught outdoors, they should immediately seek a low-lying area such as a ditch, culvert, or ravine. Lying flat on the ground in a low spot prevents the wind from lifting the body and reduces the chance of being struck by debris. Use the arms to protect the head and neck, which are the most vulnerable areas for fatal trauma.
A vehicle offers little protection, as cars and trucks are easily lifted and thrown by tornado-force winds. If driving and a tornado is approaching, immediately abandon the vehicle and seek a ditch or depression, lying flat and covering the head. Seeking shelter under a highway overpass should be avoided, as the structure can funnel and intensify wind speeds.