Relationship between anomalies of Eurasian snow and southern China rainfall in winter

Characteristics of the snow water equivalent (SWE) over high-latitude Eurasia and its relation with precipitation in China during January, February and March (JFM) are investigated. The JFM Eurasian SWE exhibited a decadal downward shift in the late 1990s, marked by a frequently positive phase in 1979-98 and a negative phase afterward. The decadal shift corresponds to anomalous northeasterly flow over southeastern China. Consequently, warm and moist airflow from tropical oceans is weakened, accompanied by reduced rainfall over southeastern China. The US National Centers for the Environmental Prediction Climate Forecast System (CFS) capture both the interannual variation and the decreasing trend of JFM Eurasian SWE reasonably well for several months in advance. The relationship between Eurasian SWE and southeastern China rainfall is also captured by the CFS in the prediction.