The National Centers for Environmental Prediction (NCEP) Eta model and its Eta Data Assimilation System (EDAS) have been successfully used for regional studies of the hydrologic cycle over the Mississippi basin. We have compiled a data set that exceeds seven years, and a climatology of the land surface-water cycle interactions was prepared. Because the Eta model is operational, its changes throughout the years may have affected the output. Nevertheless, we have not detected significant changes in the atmospheric water cycle, although variables that depend directly from model parameterizations, like evaporation, are more likely to be affected. Probably the most significant progress with the Eta model was achieved with the implementation of soil moisture cycling in mid-1998. Therefore our presentation will have two parts: the first one describes the atmospheric water cycle for the seven year period, its stability and variability. The particular effect of model changes will be addressed. The second part, based on approximately four years (1998-2002), will focus on the relationships between the land surface and the atmospheric water cycle.