Abstract
In this article, the author studied on regional characteristics of rainfall related to Baiu fronts.
Heavy rainfall concentrate in tonal area in some restricted regions, such as the middle Kinki, west Chugoku and north and west Kyusyu. These areas are freely exposed to southwest airflow working as a trigger of heavy rainfall with large amount of vapour. So the author considered that the rainfall zones may correspond to the areas freely exposed to southwest airflow. In order to confirm this idea, several examples of heavy rainfall are taken and some phenomena that seemed to supporte this idea are investigated. For example, the diurnal variations of water vapour in the lower troposphere, the upper wind conditions, and airflow trajectories are analized. By these analyses, the idea is confirmed and it becomes clear that the heavy rainfall areas are pref ectly related to the topographic conditions.
