Some Statistical Characteristics of Meiyu/Baiu Frontal Depressions

Abstract

This study has investigated climatological features of Meiyu/Baiu frontal depressions (MBFDs) by identifying and tracing MBFDs from the past 12-year surface weather charts. With apparent interannual variability, an average of 22.5 MBFDs per year are found. There is a tendency for more MBFDs to form around Yangtze and Huaihe River Basins and to the south or southeast of the Japan Islands. Meanwhile, more MBFDs form in nocturnal and morning hours per day. More than half of MBFDs that pass over Japan originate from China. MBFDs commonly propagate from west to east and many MBFDs passing over Japan tend to be long lived. Finally, the analyzed statistical characteristics of MBFDs are discussed based on previous studies.