Besides weather satellites, atmospheric measurements, and computer models, meteorologists use weather radar to forecast the weather.
Weather radar provides important information on where rain or snow is falling.
Looking at several radar images over a period of time can give clues about where and how fast the rain or snow is moving. Several images can also help show if the rain or snow is growing or shrinking in area or if it is becoming heavier. In 1975, weather radars used old vacuum tubes, similar to television sets of that era. Radar displays consisted of just two radar analysis products, and the display consisted of varying shades of gray to show different intensities of the rain or snow. Today's weather radars operated by the National Weather Service are the most sophisticated operational weather radars in the world.