Comparative Analysis of Two Rainstorm Processes in the North of Jiangxi

Based on the routine observational data of Micaps and NECP reanalysis data,a comparative analysis on large-scale circulation,low-level jet( LLJ),transportation of water vapor,vertical motion,mesoscale systems and radar echoes of torrential rain processes in north of Jiangxi province in May2013( 5. 07and5. 14) was analyzed. The results showed that: 1) The processes both belong to the type of two ridges and one troughof the circulation in Eurasian high latitudes,but their precipitation nature,environmental conditions and mesoscale characteristics are different. 2) The LLJ in the5. 07heavy rain process experienced a process of strengthening,weakening with moving eastward,reinforcing again and then weakening with moving eastward a second time,but the LLJ in the 5. 14heavy rain process has been maintained strongly. 3) The 5. 14heavy rain process was stronger than the 5. 07heavy rain process whether in water vapor or dynamic conditions. 4) The radar echoes in the5.07heavy rain process were convective precipitation echoes with narrow range and strongly located;while in the5. 14heavy rain process the radar echoes were widely convective-stratiform mixed echoes.