Application of rain radar in weather forecast

The location, moving direction, moving speed and changing trend of precipitation echo detected by 1. radar can be used to predict the precipitation in this area, its start and end time, the scope and intensity of precipitation area, etc. For example, the direction and speed of cloud and rain echo can be calculated by extrapolation, or the direction and speed of net wave unit can be calculated by using the average wind direction and wind speed between 700 and .500 mbar, so as to predict the arrival time of cloud and rain area. When several echoes merge, expand and strengthen, it shows that the weather is developing and there may be more serious weather phenomena. On the contrary, the split and contraction of frequency indicates that the cloud and rain area is weakening and the weather will improve. 2. Using the distribution, intensity, structure and evolution of precipitation echo, we can also analyze and judge the weather process. For example, according to the arrangement and motion of the echo, the position and motion of the front can be analyzed; The structure of spiral rain belt around typhoon provided by radar can also be used to judge the center position of typhoon. 3. According to the echo map (radar weather map) made by radar detection report, we can grasp the distribution of precipitation in a wider range, as well as the evolution of precipitation nature, movement and intensity. For example, Beijing's experience points out that there are usually showers when the echo height at the top of cumulonimbus clouds is below 7000m; When the ceiling height is 7000- 10000 meters, there are medium and small thunderstorms; When the ceiling height is10000-13000m, there is a thunderstorm; When the cloud top is greater than13000m, there is a great possibility of hail. Nanjing's experience shows that when the echo height of cumulonimbus cloud is above 1000 meters, the strong center is between 4000 and 5000 meters, and the center intensity is greater than 40 decibels, hail and tornado often appear.