Tornado

The precise tracking and prediction of tornadoes is not yet a reality. Meteorologists can identify conditions that are likely to lead to severe storms. They can issue warnings when atmospheric conditions are right for the development of tornadoes. They can use radar to track the path of thunderstorms that might produce tornadoes. It is still not possible, however, to detect a funnel cloud by radar and predict its path, touchdown point, and other important details. Much progress has recently been made in the detection of tornadoes using Doppler radar.

Doppler radar can measure not just the distance to an object, but also its velocity by using the Doppler effect: if an object is moving toward an observer, radar waves bounced off the object will have a higher frequency than if the object were moving away. This effect can be demonstrated with sound waves. If a car is approaching with its horn sounding, the pitch of the horn (that is, the frequency of the sound waves) seems to rise. It reaches a peak just as the car passes, then falls as the car speeds away from the listener.

Doppler radar is used to detect the motion of raindrops and hail in a thunderstorm, which gives an indication of the motion of the winds. With present technology it is possible to detect the overall storm circulation and even a developing mesocyclone. The relatively small size of a tornado makes direct detection very difficult with the current generation of Doppler radar. In addition any radar is limited by the curvature of Earth. Radar waves go in straight lines, which means distant storms that are "below the horizon" from the radar cannot be probed with this technique.

Tornadoes, which have long fascinated people with their sudden appearance and awesome destructive power, are still subjects of intense scientific study. Research continues on the formation life history and detection of these most impressive storms.