The diagnostic analysis of heavy rainfall on 1 June, 2015 in Jianghan plain

Based on conventional metrological observation data, NCEP 1°×1° reanalysis data, and ground based GPS data in Hubei province,the heavy rainfall on 1 June, 2015 in Jianghan plain was analyzed. Results show that the strong and stable water vapor transportation channel is very important to the foundation of heavy rainfall. Intensity and range of heavy rain are closely related with convergence center of water vapor flux and incremental center of entire atmosphere precipitable water vapor. Before heavy rain occurrence, energy front in lower-level, warm advection, high θse , and remarkable cyclonic circulation appear in Jianli and Honghu. The strengthening of vertical helicity in lower-level is corresponding to the enhancing of cyclonic warm shear line. Strong divergence in upper-level, strong convergence and positive vorticity in lower-level, and strong upward motion throughout whole troposphere are favorable dynamical conditions of genesis and development of mesoscale vortex in lower-level. In favorable environmental conditions, the meso-α-scale vortex genesis and development in warm shear line, and the meso-β-scale low pressure and vortex in ground surface warm inverted trough result in the heavy rainfall process on 1 June, 2015 in Jianghan plain.