A Physics-Based Empirical Model for the Seasonal Prediction of the Central China July Precipitation

July is the rainy peak month of central China, with a large interannual variation of local precipitation often causing serious droughts and floods. The seasonal prediction of the central China July precipitation (CCJP) is an important but still challenging task. Here, we suggest several robust seasonal predictors for the CCJP, including the preceding winter intensity of El Nino-South Oscillation (ENSO), the winter-to-spring decaying rate of ENSO signals in the central Pacific, as well as the spring tropical and subpolar North Atlantic sea surface temperature anomalies. A physics-based empirical model is then developed to predict the CCJP by using the principal component regression of the aforementioned seasonal predictors. In our statistical model, the seasonal prediction skill of the CCJP is high, with the cross-validated reforecast skill at 0.81 during 1993-2021. This suggests a skillful seasonal prediction of the CCJP, with potentially enormous benefits for the local society and economy.