Tornadoes usually form during supercell thunderstorms. For a tornado to form, four different factors must usually be present.
Understanding these four factors will help you know more about how tornadoes form and when you may need to be concerned about them.
Atmospheric Instability
Air must move faster than usual into the upper atmosphere. Meteorologists refer to this as the Convective Available Potential Energy. The higher the number, the more likely a tornado will form.
There are at least two common scenarios where atmospheric instability can lead to the formation of a tornado. In one scenario, temperatures climb rapidly before a cold front arrives, which creates atmospheric instability.