Characteristics of the Convective Cloud and Its Precipitation Associated with the Southwest Vortex

A simple analysis of the evolution of the convective cloud associated with the Southwest Vortex selected randomly is performed based on the FY-2C infrared (IR) and water vapor (IW) channel data in Sichuan Province.Some useful characterizations of convective cloud are found.Accordingly the analysis of the relationship between the cloud-top IR/IW brightness temperature and the rainfall is processed in combination with rainfalls from automatic meteorological observation station.It is found that rainfall rate over the past hour accumulation is, in general, related to the lowest IW brightness temperature and the change of IW brightness temperature in the past hour.Nevertheless, it is difficult to estimate the complex rainfall of the convective cloud using the cloud-top IR and IW brightness temperature data.There are different magnitudes of rainfalls produced by convective clouds of different cases although their lowest IW brightness temperatures are same.There are individual characteristics of precipitations of convective clouds occurred in each period of evolution.Even though the lowest cloud-top IR/IW brightness temperatures of convective clouds in different areas are similar at a time, the distribution and magnitude of precipitations are not same.These characteristics result in the problem on rainfall estimate of convective cloud associated with the Southwest Vortex.