Simulating precipitation processes, clouds, and hydrologic cycle at regional scale over the central US remains challenging for global climate models. ACME v1 atmosphere model has implemented many new features in the physical parameterizations. It is important to assess the persistent model biases over the central US in ACME v1 and exam how the biases respond to different model settings. This study conducts ACME v1 5-year AMIP simulations and several sets of short-term hindcasts (i.e. CAPT simulations) for the summer of 2011 with the regular grid and the CONUS RRM grid. Based on observations, especially ARM observations, the evolution of cloud and precipitation biases over the central US with various model parameter settings is analyzed in this study.