Tornadoes can be some of the most destructive extreme weather events in the world. Though the majority are small and harmless, and span only a few minutes, stronger tornadoes pose grave threats to the areas they pass over, with their high wind speeds capable of leaving a wake of carnage behind them. Though tornadoes occur across the world, the United States sustains by far the most, due to geographical and meteorological conditions in the Mid-West that promote tornado formation. Those who live in these tornado-friendly areas must be both knowledgeable about them and prepared to deal with them when the time comes.
A tornado is a violently rotating column of air that is attached to both the ground and the base of the thunderstorms that spawn them. Though tornadoes can form from all types of thunderstorms, they typically form from supercell thunderstorms, which differ in that they have a spinning column of air at their center called a vortex. Tornadoes require a few components to form: warm moist air near the surface, cooler drier air in the upper atmosphere, atmospheric instability, (in which weather can change suddenly and drastically) and wind shear (which indicates that wind changes direction and speed depending on its altitude). As the supercell grows, its vortex begins to tilt, encouraging the warm air to flow upwards and cause the vortex to swell. This movement in turn creates a spiraling funnel cloud at the center, which is the first sign that a tornado is being created. Observing funnel clouds allows scientists to detect tornados before they have fully formed, affording people in the storm's path time to find shelter.
As the warm air drifts upward, the colder air is pushed downward, which focuses the cloud into a smaller area and increases its speed. With enough pressure, the cooler air forces the spiral all the way down to touch the ground, officially creating a tornado. The winds from a tornado can top 300 mph, and have the capability of ripping apart buildings, destroying infrastructure, and even sucking water up out of riverbeds. Simply put, they have the means to cause widespread extreme devastation, though it varies depending on their strength. Different tornadoes are given a designation on the Enhanced Fujita (EF) scale, which designates them using a specific algorithm that takes into account both their wind speed and the damage they inflict. The scale ranges from F0 to F5, with tornadoes in the former category having wind speeds below 72 mph, and those in the latter having wind speeds topping 260 mph.
The US experiences over 1,000 of these extreme weather events each year, which is substantially higher than anywhere else in the world (Canada is second on the list with about 100 reported tornadoes per year). Most of the tornadoes in the US take place in an area aptly nicknamed “Tornado Alley,” though some do occur outside of it. “Tornado Alley” refers to a group of Great Plains states in the Mid-West—northern Texas, Oklahoma, Kansas, Missouri and parts of Louisiana, Iowa, Nebraska and Eastern Colorado—where there is high potential for tornado development. The reason this region is so susceptible to tornadoes is because of its position between the Gulf of Mexico to the South and Canada to the North. Warm moist area moving northward from the Gulf meets dry cold air moving southward from Canada, providing two of the necessary ingredients a tornado needs to form. Additionally, the terrain is mostly flat, further contributing to the ease with which tornadoes are created. During the spring and summer months, when thunderstorm season is at its peak, the vast areas of grasslands and croplands making up this area heat up easily. The warmer earth can create pockets of warm rising air that further entice tornado formation, making the months of May and June the most common months for hurricanes.
A series of tornadoes ripped through areas in Oklahoma, Texas, Alabama and Florida on Thursday, June 15, killing 5 total people and inflicting widespread destruction. Over 400,000 people were left without power by the morning of Friday, June 16, and hundreds of homes had been left damaged or destroyed. Of these tornadoes, one in particular—an EF-3 with a maximum wind speed of 140mph—that struck the small town of Perryton, Texas near the northern Texas border, was particularly devastating. It touched down for 11 minutes and traveled a total of 6 miles, developed quickly enough that there was no siren to indicate the impending danger to Perryton residents. The tornado left car windows shattered, hundreds of buildings destroyed, trees upended, and over 100 injured. Many businesses and mobile homes were also destroyed, with some sustaining damage from vehicles the twister had blown away.
A tornado outbreak involving at least 27 tornadoes on Friday, March 24, struck towns across Louisiana, Mississippi, Alabama, Georgia, and Tennessee, killing 25, injuring dozens, and leaving a trail of destruction in its wake. A rare long-lasting tornado, which spun for a period of 70 minutes, traveled 60 miles, and hit 170 mph wind speed and 0.75 mile width at its height, inflicted the most damage. It tore though the small Eastern Mississippi town of Rolling Rock, leveling building, downing trees, and damaging power lines. Across Mississippi, Alabama, and Tennessee, some 40,000 were left completely without power. The twister was deemed rare due to not only the distance it traveled, but also its sustained power throughout that time period. Additionally, EF-4s make up only 1% of tornadoes to start with, making the event particularly devastating for a town wholly unprepared to deal with such extreme weather.
Tornadoes, though mild the majority of the time, have the potential to turn into catastrophic events, posing huge risks to communities that lie in their paths. In order to better protect themselves, these areas can and should do a number of things to limit the damage, namely making buildings more resilient to storms by more solidly anchoring them to the ground using strong materials such as welded steel. Residents can also fortify their houses by strapping down roofs, covering windows to prevent shattering, and trimming trees to minimize the damage they can cause during storms. As the climate warms, tornadoes may even become more unpredictable. Though it is unclear what exact effect climate change will have, some evidence suggests both the possibility of stronger storms in the future, as well as new areas that will become tornado hotspots. These potential developments highlight the need for more widespread tornado-resistant infrastructure, preliminary alerts, and tornado sirens, all of which are necessary to best protect citizens. Tornadoes remain a terrifying meteorological phenomenon, however, as we continue to learn more about them, we will continue to develop means to limit the damage they can cause.