How to Read a Doppler Radar

As the popular adage goes, nothing is as unpredictable as the weather, it is quite a task to predict the sudden changes in weather conditions. However, with the invention of the Doppler radar, this undertaking has become easier. The history of the Doppler weather radar can be dated back to the era of the Second World War, especially during the Battle of Britain, where air strikes were detected using the radar. With a few additions to the old model used during the War, a newly developed radar came into existence which is used by meteorologists the world over to predict and interpret weather changes. The modern-day radar uses radio waves that are reflected back to the weather station which can be seen as computer images. In the following paragraphs let us learn to understand the signals sent by the weather radar.

Working Mechanism of the Weather Doppler Radar

Invented by Christian Doppler in the year 1842, this device helps detect and read the changes in the weather conditions and also alert the meteorologists in case of an impending storm or any other natural calamity. Doppler radar was so named because it uses the principle of the Doppler's effect. This instrument sends radio waves into the atmosphere, which may come in contact with objects. If the waves collide with the objects in the atmosphere, they are bounced back with the same velocity. The reflected waves then produce images which can be viewed on the screens in the weather stations. So if there are areas with high precipitation, hail, snow and rain etc. the waves crash against them and are retracted back. Even if the air is full of dust particles or insects, the waves bring back information regarding the same. The weather Doppler radar collects the information and portrays images based on it. The images on the screen are controlled by the closeness and frequency of the object to the radar. This device also helps calculate the speed and direction in which the wind is blowing. Once you are familiar with identifying and interpreting the signals reflected back by the radio waves it is easy to interpret a Doppler radar reading.

How to Read a Weather Doppler Radar

For reading a Doppler radar, it is essential to first identify and interpret the signals sent by the Doppler radar. Using radio waves, the changes in the atmosphere can be interpreted and necessary steps can be taken to prevent extensive damaged caused due to extreme weather conditions. The signals reflected by the radio waves in the atmosphere can be viewed on computer screens connected to the Doppler radar. The changes in the external conditions are represented with the help of different colors. Since the color codes are the main representations which help in determining the atmospheric conditions, it is essential to be aware of them. Different colors and symbols seen on the computer screen are interpretations of the radio waves which were collected by the weather Doppler radar device. Given here are some color and symbol codes regarding the Doppler radar.

• Light rain or mild snow - Light blue
• Moderate to heavy rains and light thunderstorm - Green
• Moderate thunderstorm - Yellow
• Strong or heavy thunderstorms - Red or Magenta

Bow echoes which normally appear as deep red on the screen are indicative of the direction of the storm. They are usually tough to spot in the straight line of the thunderstorm and may require closer observation of the image. Ground clutter represented by pale blue color, help meteorologists identify smog over major cities. It also indicates the level of dust, dirt and insects in the atmosphere.

The invention of the Doppler radar has proved to be a boon to the meteorological department as it has made weather predictions comparatively easier. Hope after reading this write-up you are aware of how to read a weather Doppler radar and check for climatic changes.