This system has helped people for decades
But what is the difference between a tornado watch and a tornado warning? You'll find the answer in this gallery. Click through to discover.
A tornado is a violently rotating column of air that extends from a thunderstorm to the ground.
Tornadoes form from the energy released in a thunderstorm. Although they account for only a small fraction of the storm's overall energy, that energy is concentrated in a small area, making tornadoes extremely dangerous.
Tornadoes occur in many parts of the world, including Australia, Europe, Africa, Asia, and South America. Most tornadoes are found in the Great Plains of the central United States.
Tornadoes mostly occur in the spring and summer, usually in the late afternoon or early evening. However, there have been instances of tornadoes occurring in every state in the United States on any day of the year and at any hour.
Winds in a tornado are almost always cyclonic. They turn counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. Once a tornado hits the ground, it may live for as little as a few seconds or as long as three hours.
The damage from tornadoes comes from the strong winds they contain and the flying debris they create. Wind speeds can reach over 300 mph (482 km/h) in the most violent tornadoes.
In the US, tornadoes cause around US$400 million in damage and kill around 70 people on average each year.
The deadliest tornado in world history was the Daulatpur–Saturia tornado in Bangladesh on April 26, 1989. The tornado killed approximately 1,300 people.
Meteorologists use Doppler radars, satellites, weather balloons, and computer modeling to monitor the skies for severe storms and tornadic activity.
Doppler radars record wind speeds and identify pockets of rotation within thunderstorms. Since 1971, when the Doppler radar became operational, the warning time for tornadoes grew from fewer than five minutes in the 1980s to an average of 13 minutes by the late 2000s.
Humans play an important role in tornado detection, as not all tornadoes can be picked up by Doppler radar. Citizen volunteers make up the SKYWARN network; they watch for approaching tornadoes and relay the information to the National Weather Service.
Scientists are currently testing AI-driven programs to help forecast tornadoes. The programs may be able to advise airlines to reroute planes ahead of disruptions and help disaster responders plan where they should have additional emergency crews on standby.
Further research is required, but evidence suggests climate change could be influencing the patterns of tornadoes. Warmer air and changing weather conditions may lead to more intense storms, which could create the perfect conditions for tornadoes.
Experts aren't sure what the highest wind speed might be inside a tornado, as violent tornadoes destroy weather equipment. However, the strongest tornado recorded was 318 mph (511 km/h).
Tornadoes are measured using the Enhanced Fujita Scale, which rates their strength based on the damage they cause. The scale ranges from EF0 to EF5.
A tornado watch is issued when the weather conditions are favorable for the formation of tornadoes. The watch is to let people know that tornadoes are possible due to the weather conditions.
A tornado warning means a tornado has been spotted or that a Doppler radar shows a thunderstorm circulation which can spawn a tornado.
A tornado emergency is the National Weather Service's highest alert. It is issued when a violent tornado has touched down, and there is a severe threat to human life and property.
If a tornado watch has been issued, gather your family and pets nearby to ensure everyone can get to a safe location if required.
Turn into a news station on the TV or radio to keep updated on the situation.
Choose an area that is low to the earth, away from windows, and near or against structural or underground walls. These include cellars, basements, and interior bathrooms.
Ensure your phone is charged, as this will allow you to stay up to date with news reports should you move to a safety area without a TV or radio.
Create an emergency kit with things you'll need if you have to shelter or evacuate your home. The kit should include items like food, water, and any necessary medications.
If a tornado warning has been issued, take shelter in your predetermined safe space. Use your cell phone to stay up to date with the news until the warning has been lifted.
If you're unable to make it to your predetermined safe space, find shelter under a heavy piece of furniture such as a dining table.
If you are driving when a tornado warning is issued, find a nearby structure to shelter in. Try to avoid sheltering in an underpass as they can act as wind tunnels during tornadoes.
If a tornado warning is issued while you're outside, seek shelter in a nearby structure or lie face down in a low area, such as a ditch, and protect your head.
Sources: (National Geographic) (NOAA National Severe Storms Laboratory) (National Weather Service)
See also: Stunning pictures of the world's strangest and rarest weather phenomena
What’s the difference between a tornado watch and a warning?
There's a big difference between these two alerts!
LIFESTYLE Alert
According to experts, the United States averages over 1,150 tornadoes every year—that's more than any other country on Earth. Thanks to modern observing systems, forecasters can see the signs of a potential tornado in advance but forecasting when and where tornadoes will form is still difficult. The US National Weather Service plays a crucial role in tracking, predicting, and responding to tornadoes and will issue watches or warnings depending on the severity and likelihood of tornado development.
But what is the difference between a tornado watch and a tornado warning? You'll find the answer in this gallery. Click through to discover.