Tornadoes are powerful and dangerous rotating air that form within thunderstorms. They are funnel-shaped clouds that extends from the base of the storm cloud to the ground. Tornadoes can cause significant damage to buildings and can pose a serious threat to humans. They usually occur in the mid-latitudes of the Northern Hemisphere.

Tornadoes form from rotating thunderstorms, also known as supercells. The full and exact process of tornado formation is still not fully understood, but it most likely involve the following steps:

1. Moist air rises and cools, creating thunderstorm clouds.
2. Wind shear, or the change in wind speed and direction with height, causes the rotating wind in the thunderstorm to intensify.
3. The rotating updraft becomes a mesocyclone, which is a vertically rotating cloud mass which can possibly extend several miles into the atmosphere.
4. If conditions are right, the mesocyclone can produce a tornado.

The precise combination of meteorological conditions that lead to tornadoes forming is not well understood, but it is probably to involve the presence of warm, moist air near the ground and cool, dry air aloft, as well as strong wind shear and instability. Tornadoes are most likely to form in the spring and around early summer.

To survive a tornado, it’s great to follow these steps:

1. Find shelter: Find a low-lying, sturdy building or go to a basement if possible. Don’t go near windows and protect yourself with something like a mattress or blanket.
2. If in a car: Avoid parking under a bridge or overpass, as winds can be stronger there. Instead, you should drive to the nearest shelter or lie flat in a low ditch.
3. Stay informed: Listen to local news and weather reports for updates and follow any emergency alerts and evacuation orders.
4. Protect your head: Cover your head and neck with your arms or a cushion to protect yourself from debris flying around.
5. After the tornado has passed: Avoid any sort of electricity, like power lines and also avoid damaged buildings until it has been deemed safe by authorities.

It’s also important to have an emergency plan and to know the tornado warning signs, for example:

• A dark, usually greenish sky
• A large, low-lying cloud
• A roar that sounds like a freight train