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This study assesses the midsummer precipitation prediction over eastern China by the dynamic downscaling method. Based on the Climate Forecast System version 2 of the National Centers for Environmental Prediction and the Weather Research and Forecasting Model, the prediction performance of global and regional models on the July precipitation over eastern China is further analyzed by hindcast experiments from 1982 to 2010 and prediction experiments from 2011 to 2021. The results suggest that the regional model forced by the global model can noticeably improve the prediction skill for precipitation in eastern China, especially in the region from the South of North China to the Yangtze River Basin, referred as the northern China in this paper. In addition, we perform a diagnostic analysis of the reason for the improvement of the model prediction skill. The results indicate that the high resolution of the regional model and the refinement of physical process parameterizations contribute to improving the simulation ability for the East Asian atmospheric circulation pattern, heat flux, especially for the meridional teleconnection pattern in East Asia and the sensible heat flux in the northern China, thus further improving precipitation prediction. [ABSTRACT FROM AUTHOR]

Northeast China is a major agricultural production base in East Asia, and spring is the agricultural ploughing season throughout the region. The precipitation in spring is therefore significant to agricultural activity and production in the region. In this study, the interdecadal variation in spring precipitation across northeast China is investigated. In the past four decades, there has been a significant increase in spring precipitation in northeast China, and the increase in May precipitation made a dominant contribution to that increase. Further analysis indicates that the increase in May precipitation is concurrent with the decline in Arctic sea ice concentration (SIC) over the Barents Sea; both variables show an interdecadal shift around the early 2000s. Physical analysis based on observations and numerical simulations demonstrates that a decline in the Barents Sea SIC could excite a Rossby wave train propagating southeastward across the Mongolia‐Baikal region and reaching northeast China, thereby inducing a zonal anticyclone–cyclone–anticyclone teleconnection pattern over mid‐ to high‐latitude Eurasia. Under the influence of such a teleconnection pattern, significant southerlies prevail over northeast China, bringing warm and wet air to the region; in addition, the local atmospheric instability and upward motion are also increased. The changes in the moisture and dynamic conditions favour the increase in May precipitation over northeast China. Furthermore, SIC anomalies in the Barents Sea persist from late winter to spring; therefore, the SIC signal could provide signals for predictions of the interdecadal changes in May precipitation over northeast China. [ABSTRACT FROM AUTHOR]