Copyright June/July 1996 by Weatherwise magazine
Radar stands for RAdio Detection And Range.
The radar receiver dish picks up the radio waves which have bounced off of raindrops, snow, or hail inside a cloud, and changes them into dots and blips of light that show up on a fluorescent screen.
Using radar, a weather person can see if rain is on the way. Each radar covers an area of about 124 miles and picks up echo signals of the rain.
In the USA, radar is used to follow storms minute by minute so that tornado warnings can be given.When the weather forecaster on TV shows you a "radar picture", he or she is showing you the picture of what the radar pulses reflected off precipitation sized particles, mountains, and other obstacles.
The following images were produced by special cloud sensing radar, which provides measurements of non precipitating and drizzle producing clouds, as well as snowstorms: