陇东南地区一次暴雨过程中尺度分析

Using hourly precipitation data of regional stations in Gansu province, NCEPNCAR reanalysis data, upper airsurface observation data, TBB products of FY-2E satellite and radar data, a heavy rainstorm process occurred in the southeast of Gansu province from June 19 to June 20, 2013 was analyzed. The results show that the immediate cause of the heavy rain was the MCC formed by a line of convective clouds occurred in the southeast of Gansu connected to the severe convection system originated in central Sichuan moving northeast under the favorable situation of the large circulation. Heavy rainfall happened in the convection instability area and the moving front of it. The low-level jet brought in water vapor, lower convergence and upward movement provided water vapor and dynamic conditions for heavy rainfall. The region where TBB reduced quickly and radar echo intensity which is higher than 40 dBz has a good indication for forcasting heavy rainfall area. Short-time heavy rainfall will be more likely to occur in the area that the inverse wind area generated or passed through within 2 hours.