This study investigated the connection between the Australian summer monsoon (ASM) and summer precipitation over central China. It was found that, following a weaker-than-normal ASM, the East Asian summer monsoon and western North Pacific subtropical high tend to be stronger, yielding anomalous northward moisture to be transported from the western Pacific to central China. Besides, anomalous upwelling motion emerges over 30–37.5°N, along 110°E. Consequently, significant positive summer precipitation anomalies are located over central China. Further analysis indicated that the boreal winter sea surface temperature (SST) in the Indian Ocean and South China Sea shows positive anomalies in association with a weaker-than-normal ASM. The Indian Ocean warming in boreal winter could persist into the following summer because of its own long memory, emanating a baroclinic Kelvin wave into the Pacific that triggers suppressed convection and an anomalous anticyclone. Besides, the abnormal SST signal in the South China Sea develops eastward with time because of local air-sea interaction, causing summer SST warming in the western Pacific. The SST warming can further affect East Asian atmospheric circulation and precipitation through its impact on convection. 

Correlation between boreal summer (June–August, JJA) precipitation anomalies during 1979–2014 and (a) Australian summer monsoon index (ASMI) (December–February, DJF) and (b) preceding winter (DJF) Ni？o3.4 index. Light (blue and yellow) shading are at the 90% confidence level, and dark (blue and yellow) shading are at the 95% confidence level based on the Student’s t-test. (c) As in (a), but with the signal of ENSO removed. (d) Vertical-horizontal cross section along 110°E for vertical wind (vectors; units: m s^？1) and omega (shading, units: ′ 10^？3 Pa s^？1) anomalies during the summers of 1979–2014 regressed onto the ASMI (signal of winter ENSO removed). Omega anomalies enclosed by thick contours are at the 90% confidence level based on the Student’s t-test.