The maximum monthly storm duration appears in June (Figure 3) during which the precipitation is mainly dominated by the Meiyu system. The relatively longer storm duration is mainly a product of the quasi-stationary front. There are no storm events during this period which has a total amount of precipitation over 250 mm. However, it is worth noting that large storm events with higher average storm intensity also exits during MFS (26 storm event with total precipitation larger than 100 mm, Table 2) due to the quasi-stationary and slow-moving linear mesoscale convective systems (Wang et al. 2014). Storms in July and August are characterized by shorter duration and higher intensity as the storms during the hot summer are mainly produced by the local convective systems and typhoons. So, the total precipitation during TFS is larger than that of MFS in the study area while the average account of storm events and the average storm duration are all smaller. In other words, the larger precipitation amount during TFS is mainly due to higher intensity storm events, which could be further proved by the account of storm events of which the total precipitation is larger than 250 mm in Table 2. Mass curves of three levels from TFS storm events show a broader range than that of MFS, indicating that the within-storm pattern is more uncertain and unsteady during TFS under the impact of tropical cyclones with huge power and abundant moisture.