Diagnostic Analyses of Typhoon Torrential Rain over Liaodong Peninsula
Using the Tropical Cyclone Yearbook，two dimensional Fengyun (FY 2E) 0.1°×0.1° cloud top brightness temperature data, hourly rainfall observations from nearly 100 automatic weather stations (AWS) , conventional observation data and the NCEP/NCAR reanalysis data, large scale circulation characteristics and mesoscale circulations were analyzed for typhoons of 1209 (Saola) and 1210 (Damrey). The results show that: (1) Northerly and stable position of subtropical high pressure (STP) provides favorable large scale circulations. The direct raining system is the mesoscale convective complex (MCC), which is generated by the development of meso β or meso γ rain clusters located in the east of typhoon and the west of STP. (2) Link of the area of Liaodong Peninsula with the channel of moisture transported by lower level jets and the formation of moisture convergence are responsible for the occurrence of heavy precipitation in the area. Standing link of water vapor transport belts for typhoons of Damrey and Saola is favorable for genesis and development of convective complex in typhoon rain belts, beneficial to the genesis of severe rainfall. (3) Near the center of Damrey, the coupling dynamical structure of positive vorticity and the negative divergence form, which causes strong upward motion in the lower troposphere, and has the convergent water vapor at the lower level lifted to the middle level, good for genesis and development of MCS. Moving northeastward along the periphery of STP, MCS rapidly develops and results in heavy precipitation. The heavy rainfalls are located at lower level jet belts of the east of Damrey and the west of STP. （4）The local vertical circulations in the south of Liaodong Peninsula are helpful for the formation and development of mesoscale convective cloud clusters.