How are they detected?
Today, the development of Doppler radar has made it possible, under certain circumstances, to detect a tornado’s winds with a radar. However, human beings remain an important part of the system to detect tornadoes, because not all tornadoes occur in situations where the radar can “see” them. Ordinary citizen volunteers make up what is called the SKYWARN (www.skywarn.org) network of storm spotters, who work with their local communities to watch out for approaching tornadoes, so that those communities can take appropriate action in the event of a tornado. Spotter information is relayed to the National Weather Service, which operates the Doppler radars and which issues warnings (usually relayed to the public by radio and TV) for communities ahead of the storms, using all the information they can obtain from weather maps, modern weather radars, storm spotters, monitoring power line breaks, and so on.