Spatio‐Temporal Characteristics of Heavy Rainfall Events During the Changma in Southeastern Korea

Abstract In southeastern Korea, various synoptic conditions are responsible for heavy rainfall events (HREs) exceeding 30 during the Changma, that is, the Korean summer monsoon season. We objectively classify such synoptic patterns of HREs using a self‐organizing map with sea level pressure and 850‐hPa geopotential height fields as input variables. A total of eight synoptic clusters (SCs) are identified. The first three clusters (SC13), which explain about 18% of HREs, are influenced by tropical cyclones. Excluding minor cluster SC4, SC58 are dominated by midlatitude weather systems with a southeast‐high or northwest‐low pattern. When examining HREs not influenced by tropical cyclones, SC5 and SC8 show contrasting synoptic patterns. SC5 is influenced by an eastward‐propagating surface low, whereas SC8 is associated with an expansion of the Western North Pacific Subtropical High (WNPSH). …