In recent years, several winters with extreme and long-lasting precipitation events in South China have led to extensive structural damage and economic losses. Precipitation prediction tools are not very skilled in characterizing subseasonal events and need to be improved. A new research study, funded in part by the Climate Program Office’s Climate Variability & Predictability (CVP) Program, identified three distinct circulation patterns that cause and enhance precipitation over South China during winter. A team of international researchers, including CVP-funded scientist Dr. Tim Li of the University of Hawaiʻi at Mānoa, used observational data from 1979-2016 to understand the critical intraseasonal circulation systems and the mechanisms which impact precipitation variability. Their results, published in Climate Dynamics, show three categories of circulation with differing timescales and intensities which contribute to extreme precipitation events in South China, helping improve regional prediction capabilities. This work contributes to ongoing efforts by CVP to improve modeling simulation of precipitation on a subseasonal timescale.