Significant advances in understanding and predicting the behavior of the coupled land-atmosphere system on large space and time scales can be effectively achieved through regional projects that marshal substantial resources and entrain a large range of multi-disciplinary expertise. This presentation reviews the advances that have been and are being made through two such projects, namely the GEWEX (Global Energy and Water Cycle Experiment) Continental-scale International Project (GCIP) and the follow-on GEWEX Americas Prediction Project (GAPP). GCIP has contributed to understanding and modeling the interactions of soil moisture, snow, frost, vegetation and hydrological processes with the atmosphere. In addition to measuring and understanding individual processes, the project has also contributed to the improvement of coupled atmosphere-hydrology models and more extensive use of advanced earth observing satellite systems in model development. The benefits of this research for closing water and energy budgets for the Mississippi River Basin, for improving prediction services and data assimilation systems and products, and for improved water resources management have also been demonstrated in GCIP.

GAPP contributes to the second phase of GEWEX’s hydrometeorological mission to demonstrate "skill in predicting changes in water resources on time scales up to seasonal as part of a climate prediction system." GAPP will give more emphasis to quantifying land memory processes and predictability, studying monsoon and orographic processes that control precipitation patterns over the USA, developing prediction systems, and linking continental research to the global perspectives that are so crucial to GEWEX and other WCRP initiatives. In doing so GAPP will expand its focus beyond the Mississippi River Basin to study 1) monsoonal processes along the Gulf of Mexico and in the Southwest, 2) winter and spring processes that dominate the hydrometeorology of the western Cordillera, and 3) water resource applications throughout the United States.