The radar signal is transmitted by a rotation dish antenna mounted on a tower. As the dish rotates in all directons, it sends signals that quickly bounce off of precipitation within a cloud. It doesn t take long for an echo to return to the radar dish. The meteorologist can track the storm on the radar scope to determine how a storm is moving. The line sweeping around the radar screen represents the radar antenna rotating in all directions.
Some scopes can show precipitation in color.
The heavier the precipitation, the stronger the echo. Weather radar can detect six different intensities of precipitation, assigning a color to each. Although the colors can vary from station to station, the lightest precipitation is usually blue and green, with the heaviest precipitation yellow and red. These colors tell a meteorologist how much rain could fall on an area in one hour. The newest type of weather radar is called Doppler.