Weather Forecast Of Rainfall Based On Storm Relative Helicity

With the development of science and technology, more and more various weather forecasting methods have been imposed, and more and more information has been provided by weather monitoring tools. So how to make forecasts more accurate has gotten people's attention.Storm relative helicity(SRH) is a physical quantity which can describe the development intensity of convective storm. The forecast of rainfall with storm relative helicity has 0.5-2 hours ahead of the occurrence of actual rain. For more complex composite weather types, there are also many obvious features which can be used in the weather forecast.The major work included:(1) Radar base data was read and stored, and to reduce the influence of noise quality of radial velocity data was controlled. Then field data was obtained by VAD(Velocity-Azimuth-Display).(2) Wind vector map shows the change of wind field with height,wind shear condition with height intuitively, and SRH shows the development intensity of convective storm in figures,so wind vector map was set up and SRH was calculated.(3) According to meteorological knowledge and digital image processing technology, features of storm were extracted from the Doppler radar reflectivity image to describe the storm. These features provided conditions to limit the use of SRH.(4) The base data of wind and actual weather rainfall were compared and analyzed, so that the rules of SRH describing the weather had been gotten.To sum up, according to the application conditions of SRH and the study of data quality, prediction rules under different conditions had been gotten, which meet the requirements of weather forecast.