Tornadoes appear as violently rotating funnel-shaped columns of air that extend from thunderstorms and stretch from convective clouds to the ground. Tornadoes are the product of severe thunderstorms, which produce other phenomena like strong gusts of wind, lightning strikes, and flash floods. It may be difficult to always receive a warning for tornadoes because of how quickly they develop.
Some tornadoes are visible, while rain or nearby low-hanging clouds may obscure others. They mostly become visible when they form a condensation funnel made up of water droplets, dust, and debris. The strongest tornadoes have rotating winds of more than 250 mph. They can be more than one mile wide and stay on the ground for over 50 miles. The average forward speed of a tornado is 30 mph but may vary from nearly stationary to 70 mph.
Warm, moist, and unstable air are important characteristics of severe thunderstorms which develop tornadoes. The movement of air particles from a region of high pressure to a region of low pressure creates wind. Wind speeds and directions are different at separate altitudes, and the difference is called "wind shear." Vertical wind shear is the change in the wind's direction and speed with height. As the wind begins to pick up speed, this movement of air particles causes winds to blow at different speeds and in different directions at different altitudes. Cyclically blowing winds form a horizontal tube of air.
During a thunderstorm, an updraft (warm air currents rising within the storm to form convective clouds) can turn the horizontal tube of air into a vertical one. The unstable air mass promotes the development of strong updrafts, while wind shear further increases the strength of the updraft and promotes tornado-spawning rotations. This continued rotation creates a supercell. A tornado is born when a funnel cloud touches the ground. After the funnel touches the ground and becomes a tornado, the color of the funnel will change, and the winds will become more powerful. The color often depends upon the type of dirt and debris it moves over and picks up.
Although all thunderstorms can spur a tornado, a supercell is the type that is most likely to do so. A supercell is defined as a thunderstorm consisting of one quasi-steady to rotating updraft, which may exist for several hours. It is a rotating thunderstorm with a well-defined radar circulation called a mesocyclone. Storms possessing this structure generate the vast majority of long-lived strong and violent tornadoes, as well as downburst damage, flash floods, and large hail. Notably, not all supercells result in tornadoes - only 30 percent or less produce tornadoes.
Outside of the US, tornadoes can form in many other parts of the world, including Australia, Europe, Africa, Asia, and South America. Tornadoes can occur and have been reported in all fifty states. The Great Plains of the central United States are an ideal environment for the formation of the type of thunderstorms (supercells) that spawn tornadoes. Cool, dry air in the upper levels of the atmosphere, in this region, caps warm, humid surface air. Storms develop as dry cold air moving south from Canada meets warm moist air traveling north from the Gulf of Mexico.
Tornado Alley is a loosely defined area of the central United States where tornadoes are most frequent. Although it is not an official term, it refers to a wide swath of tornado-prone areas between the Rocky Mountains and the Appalachian Mountains that frequently experience tornadoes. The idea of a "tornado alley" can be misleading. This is because the tornado threat in the US shifts from the Southeast in the cooler months of the year toward the southern and central plains in May and June and the northern plains and midwest during early summer. Therefore, tornadoes can occur outside the tornado alley.
Tornadoes can occur at any time throughout the year. However, they can be more frequent in some periods. Tornado season refers to the time of the year when tornadoes are most likely to occur. In the southern states, tornado season is from March through May, and tornadoes peak during the summer in northern states. Tornadoes are more likely between three and nine pm even though they have occurred at all hours and can last from several seconds to more than an hour but most last less than 10 minutes.
A twister is another name for a tornado - both terms refer to the same phenomenon. The latter appears to be a slang term for a tornado because of how it acts. Other distinct phenomena are closely related to tornadoes. Waterspouts are whirling columns of air and water mist which can be fair-weather waterspouts or tornadic waterspouts. Tornadic waterspouts are simply tornadoes that form over the water and have similar characteristics. Severe thunderstorms, high winds and seas, large hail, and frequent dangerous lightning are common features of tornadic waterspouts.
Fair-weather waterspouts are more common but usually less dangerous phenomena. The term fair weather comes from the fact that this type of waterspout forms during fair and relatively calm weather, often during the early to mid-morning and sometimes during the late afternoon. Unlike tornadic waterspouts, which develop in mature severe thunderstorms, fairweather waterspouts are generally associated with the formative stage of showers and non-severe thunderstorms.
A dust devil is a common wind phenomenon made up of dust-filled vortices created by strong surface heating, which is generally smaller and less intense than a tornado. They are different from thunderstorms. Typical diameters of dust devils range from 10 to 300 feet, with an average height of approximately 500 to 1000 feet. In most places, dust devils typically last only a few minutes before dissipating.
The size or shape of a tornado is no measure of its strength. Tornadoes are categorized based on estimated wind speed and related damage. This rating system is the Enhanced Fujita (EF) scale, and it is an improvement on the old system, the Fujita scale. The change was necessitated by the inadequacies of the previous rating system.
The Fujita scale was developed based on damage intensity and not wind speed; the scale estimated wind speed ranges based on the extent of observed damage. The new and improved EF scale is better suited to align wind speeds more closely with associated storm damage. There are six categories on the scale ranging from EF0 to EF5:
EF Rating | 3 Second Gust (mph) |
0 | 65-85 |
1 | 86-110 |
2 | 111-135 |
3 | 136-165 |
4 | 166-200 |
5 | Over 200 |
About 1,000 tornadoes hit the US yearly, resulting in 80 deaths and over 1,500 injuries, and they cost more than $400 million in property damage. The damage caused by tornadoes comes from the strong winds they contain and the flying debris they create. Tornadoes are capable of causing extreme destruction, including uprooting trees and well-made structures and turning normally harmless objects into deadly missiles.
Violent tornadoes can pose a deadly threat to people. During a tornado, individuals face hazards from extremely high winds and risk being struck by flying or falling objects and getting seriously injured or worse. Violent tornadoes are responsible for nearly 70% of tornado-related fatalities, even though they only comprise two percent of all tornadoes.
Also, tornadoes are a real hazard to the agricultural sector. Strong winds can uproot trees and ravage buildings. Tornadoes passing over fields can cause significant damage to crops, and tornado tracks of fallen or lodged crops can extend for many hundreds of meters. Livestock may also be fatally injured by strong winds and flying debris if farmers do not take adequate care to protect them from tornadoes. There have been reports of tornadoes, rated as low as EF 0, damaging nearby crops.
Property destruction is one of the more common effects of a tornado disaster. Mobile homes are very vulnerable to winds from a tornado, even relatively weak ones, and mobile home communities usually are the source of most graphic reports of tornado damage. In addition, winds above 200 mph can level well-constructed homes, blow away structures with weak foundations, throw cars, and generate large missiles.
Even though North Carolina falls outside of the region classed as Tornado Alley, the state experiences its fair share of tornado disasters. The state sees an average of 30 tornadoes each year, according to the State Climate Office. Tornado season in North Carolina is between March and May. The state office reports the highest tornado average to be in May at five, followed by April and September, tied for second with four each. In third place is the month of March, which averages three tornadoes per year.
A report published by the Storm Prediction Center identified the Carolinas region as one of the four main tornado alleys in the US. The main alley extends southwestward across eastern and southern North Carolina. This area is located in the flatter terrain east of the Appalachian Mountains. With 9.40 per 1,000 square miles, Scotland County in southern North Carolina to the east Southeast of Charlotte, North Carolina, was reported to have the highest frequency of long path F3 to F5 tornadoes east of the Appalachian Mountains.
Violent tornadoes have wreaked havoc in the state in the past. In August 2020, Tropical Storm Isaias produced several EF-2 tornadoes and one EF-3 tornado across coastal North Carolina, and the single EF-3 tornado was reportedly responsible for two fatalities in the state. Isaias was responsible for 52 tornadoes that developed across North Carolina, Virginia, Maryland, Delaware, and New Jersey.
Another historical occurrence is the three-day period from April 14-16, 2011, where more than 177 tornadoes erupted across the country, and 30 of those were confirmed to have affected North Carolina. The tornadoes were responsible for the deaths of 22 people, including 12 in Halifax County. This outbreak also included strong tornadoes in Snow Hill, Havelock, and Jacksonville in eastern North Carolina.
Adequate preparation for tornadoes is necessary, especially when expecting a tornado. Remember to check weather forecasts regularly and monitor local news and weather radios to receive updates on tornado warnings and watches.
North Carolina residents will find it useful to draw up emergency plans for individuals as well as family emergency plans for families. These plans should contain an emergency meeting place and related information about emergency contacts and medical information for family members. When preparing to evacuate, emergency plans should also contain routes to safety shelters, and it may be helpful to visit safety shelters to help family members and pets locate them easily. A family severe thunderstorm drill will help everyone know what to do if a tornado is approaching. Ensure all family members know how to locate the emergency meeting place or shelter when local authorities issue tornado warnings.
Additionally, there should be an emergency kit that should contain the necessary medication and tools for medical emergencies. The emergency kit should include essential items that will help sustain a family for up to three days in the event of being isolated in the home without power during a disaster. It is also advisable to stock up on supplies such as food and water when preparing for a tornado. Remember to make extra provisions for family members and pets with special needs.
Remember to include pets and service animals in an emergency plan, and they should have their supply kits. Keep a supply of necessary medication and treats that can last for at least a week. Take pets along when evacuating for their safety. Remember not to allow pets to run free during a tornado, as they can get seriously injured. Bring them indoors at the first warning of a tornado. Pet owners ought to identify nearby animal shelters, boarding kennels, veterinary clinics, grooming facilities, and the homes of family and friends where they can take pets during an emergency.
In preparing the home for a tornado, it may be necessary to carry out structural repairs on buildings and interior rooms. It may be useful to have a safe room in the home to wait out a tornado when evacuation is impossible or not advised. The Federal Emergency Management Agency (FEMA) provides useful information and resources on how to construct safe rooms. Furthermore, board up windows and doors and secure them with proper materials to avoid damage from flying debris. Trim trees to prevent damage from broken branches. Bring in outdoor equipment like lawn furniture and outdoor grills to prevent them from being flung around during the storm.
The extent and financial cost of a windstorm can be very severe. Homeowners find it very useful to get homeowners' insurance to soften the burden. Comprehensive homeowners' insurance policies will likely cover damage from inclement weather disasters such as tornadoes, but it is expedient to review the policy to make sure it is expressly covered.
Remove cars, trucks, and boats from probable tornado paths and move them to secure locations to ensure their protection or reduce the risk of damage. Car owners and boat owners should endeavor to obtain comprehensive auto and vehicle insurance coverage from tornado disasters to pay the cost of repair or actual cash value (ACV) of the automobile, less any deductible.
Tornado warnings and alerts are necessary to ensure safety from tornado disasters. The National Weather Service Storm Prediction Center issues tornado watches and warnings to alert the public of potential severe weather. Issuing a Tornado Watch indicates that tornadoes are possible. Remain alert for approaching storms and be ready to shelter immediately. Watch the sky and stay tuned to NOAA Weather Radio, commercial radio, or television for information. During a watch, endeavor to review and discuss family emergency plans, check supplies, and assess the safe room. A tornado warning is issued when a tornado has been sighted or indicated by weather radar. A tornado warning means residents are required to take shelter immediately.
In addition to watches and warnings, some localities may have tornado sirens. These are outdoor warning systems designed only to alert those who are outside that something dangerous is approaching. After hearing a siren, residents ought to immediately go inside and tune in to local media to get more information.
Residents can expect to receive emergency messages from state and local governments and the National Weather Service via television, radio, weather radios, social media, and alerts on cellular phones. Individuals must make sure they have a way to monitor severe weather conditions and receive emergency alerts at all times. NOAA Weather Radio, local radio, or television are common sources for the latest weather and river forecasts.
The NOAA Weather Radio All Hazards (NWR) is a nationwide network of radio stations broadcasting continuous weather information directly from the nearest National Weather Service office. NWR broadcasts official Weather Service warnings, watches, forecasts, and other hazard information 24 hours a day, seven days a week. Among the 750 Weather Radio transmitters found across the United States, over 27 of those transmitters, which are located within North Carolina and three neighboring states, provide necessary weather updates to the state. NOAA weather radios can be purchased at local electronics stores.
The Emergency Alert System (EAS) is a national public warning system that broadcasts emergency messages via radio and TV. It is implemented, maintained, and operated at the federal level by FEMA in partnership with the Federal Communications Commission and NOAA. Participation by radio and TV stations is voluntary, but organizations that join the EAS must agree to the rules in the North Carolina Emergency Alert System Plan.
Wireless Emergency Alerts (WEA) are short text-like alert messages sent by government-approved staff during an emergency to give people a free and fast way to get key details. It also sends details about AMBER alerts or other problems in your area. There is no need to get an app or subscribe to the service. Just ensure to turn emergency alerts on in the notifications settings on the mobile device.
Tornado warnings and alerts may not always be early enough or even accurate. Meteorologists can predict when conditions are right for the formation of a twister, but it may not be as easy to determine who is in grave danger and at what time. The rapid development of tornadoes and the spontaneity of their occurrences make them tricky to predict accurately.
Residents must determine the tornado risk in their areas to adequately prepare for disasters. Residents must always be on the lookout for tornado signs and remain alert for weather forecasts, warnings, and watches. Some useful signs that a tornado is imminent include:
It may also be helpful for North Carolina residents to consult state resources when assessing whether or not they reside in tornado-prone areas. The Storm Prediction Center website provides real-time information on weather trends, and these can be quite useful for residents in ensuring tornado safety.
To stay safe during a tornado, stay aware of weather conditions during thunderstorms. Individuals should take measures to protect themselves (especially the head) from injury. Between April 25 and 28, 2011, a massive storm system generated 351 tornadoes, which led to the deaths of 338 persons. The leading cause of death was traumatic injuries, including 21.9% with head injuries.
Residents ought to know the best places to shelter, both indoors and outdoors. Basements, storm cellars, and rooms on the lowest floor are useful places to take shelter at home during a tornado. The best shelter from a tornado is a basement. An interior room without windows on the lowest level of the home may also suffice. Residents should ensure to keep away from windows and doors during a tornado as the window glass can quickly become debris in the face of strong winds.
When outdoors, residents should immediately seek tornado shelters or secured buildings to take shelter in. Mobile homes offer little protection from tornadoes. Even mobile homes with a tie-down system cannot withstand the force of tornado winds. Thus, residents in mobile homes should evacuate immediately and go to the lowest floor of a sturdy, nearby building.
Do not try to outrun a tornado in a vehicle. Persons in the path of a tornado should safely exit the vehicle and take shelter in a sturdy building or a nearby gully, ditch, or low spot on the ground by laying face down and covering their neck and head with an object or their arms.
After a tornado, there are many hazards survivors could face, including injuries from walking among debris or entering damaged buildings. Tornado survivors who had previously evacuated should continue to shelter in place and avoid returning to the area until local authorities declare it safe to do so. It is crucial to keep up with updates and guidelines even after a tornado has passed by continuing to monitor local radio and TV stations.
Some tornado survivors may be injured and may be in need of medical care. Do not attempt to move seriously injured people unless they are in immediate danger of further injury. Experienced individuals are best suited to administer first aid to injury victims. Contact a healthcare provider or other emergency services as soon as possible.
After a tornado, the network signal may be lost. It is, therefore, important to save phone calls for emergencies and use text messaging or social media to communicate with family and friends.
When returning to a tornado-ravaged area, stay clear of fallen power lines or broken utility lines hanging overhead or on the ground in order to prevent electrical hazards. Contact the electric company immediately.
It is also advisable to do a damage assessment by carrying out inspections to discover possible structural, electrical, or gas-leak hazards in the home. Make sure to document hurricane damage with photographs and reach out soon enough to the insurance company when a property has been damaged during the disaster.
During clean-up, endeavor to wear appropriate gear such as thick-soled shoes, long pants, and work gloves. Use appropriate face coverings or masks when cleaning up debris. Power outages are normal during and after hurricanes. It is safer to use flashlights rather than candles. If portable generators are to be used, they should be installed outdoors. There is the risk of carbon monoxide poisoning from generators when used indoors or in the garage, which can be fatal.
There are a number of state resources that offer assistance to victims of tornado disasters. The Individual Assistance Program provides assistance to tornado victims who have lost their primary residences due to a natural or manmade disaster. Victims are encouraged to obtain financial assistance to acquire new housing, reinstate or repair the existing property, and even get medical care.