You look outside and see something terrifying. A massive tornado is moving toward you, and you know you need to find shelter immediately. Then, just when you think things cannot get worse, another tornado appears nearby.Two tornadoes are approaching at the same time. Are you trapped, or is there still a way to survive? The good news is that knowing what to do before a storm arrives can greatly improve your chances.Twin tornadoes form when powerful rotating thunderstorms called supercells produce multiple tornadoes at once. These storms can last for hours and create several violent tornadoes during their lifetime.Two tornadoes happening together are called twin tornadoes, while three are known as triplet tornadoes. Although they sound rare, these events happen hundreds or even thousands of times each year in the United States.But what makes twin tornadoes so dangerous?The biggest problem is that they can be unpredictable. The tornadoes may move in different directions, vary in strength, and appear close together or several kilometers apart.Never Underestimate Two TornadoesWhen twin tornadoes form, one is usually stronger than the other. But sometimes both can become extremely powerful.In 2014, the small town of Pilger, Nebraska, was struck by twin tornadoes with winds reaching about 320 km/h (200 mph). The two tornadoes were only about 1.6 km (1 mi) apart and destroyed buildings across a path stretching around 24 km (15 mi). The disaster killed two people, including a young child.Tornadoes can change quickly, and even experienced storm researchers know how dangerous they can be. Never assume you can predict a tornado’s path or strength, especially when two are forming at the same time.Watch for Warning SignsSupercell storms can be difficult to recognize, but there are signs that danger may be nearby.If you hear a loud roaring or whistling sound, see a dark rotating cloud, or notice an unusual green color in the sky, it could mean a severe storm is approaching.When a tornado warning is issued, do not wait to see the tornado yourself. Move immediately to a safe location.The best option is an underground shelter or a sturdy concrete building. Before severe weather arrives, know where your nearest shelters are and how to reach them quickly.It is also smart to prepare an emergency bag with important documents, water, canned food, a flashlight, batteries, cash, a phone charger, blankets, and a portable radio.Get Away or Get BelowTwin tornadoes can form in different ways. Sometimes a second tornado develops as part of the same storm system, while in other cases a smaller satellite tornado forms and rotates around a larger one.Because supercell storms can stretch more than 16 km (10 mi) wide, escaping the tornado itself is not enough. You need to avoid the entire storm system.If you cannot leave the area safely, get underground or move into the strongest interior room of a sturdy building.Wear a HelmetOne simple item could make a huge difference during a tornado: a helmet.During the deadly 2011 Joplin, Missouri, tornado, which killed more than 160 people, some survivors escaped because they protected themselves from flying debris.One mother placed a bike helmet on her child moments before the tornado hit their home. The storm destroyed the house, but the helmet helped protect the child from dangerous impacts.During a tornado, flying objects are one of the biggest threats, so wearing a helmet can provide extra protection.Protect Your EarsA powerful tornado can sound like a freight train. If two tornadoes are nearby, the noise can become overwhelming.The extreme pressure changes during a tornado can also make your ears feel painful, even when you are inside a shelter. Covering your ears can help reduce discomfort and panic while you wait for the storm to pass.Stay Inside Until It Is SafeAfter a tornado moves away, do not rush outside immediately. More storms could follow, power lines may be down, and dangerous debris could be everywhere.Stay in your shelter until officials confirm that it is safe to leave.Twin tornadoes may look like something impossible to survive, but preparation matters. Knowing where to go, what to bring, and how to react quickly can give you the best chance of making it through one of nature’s most dangerous events.