A dense Global Navigation Satellite System (GNSS) meteorological network (similar to 20 stations) in the central Amazon Basin in Brazil is being developed for long-term studies of deep convection/water vapor interactions and feedback. In this article, the network is described and preliminary results are presented: GNSS-derived precipitable water vapor is useful for tracking water vapor advection and in identifying convective events and water vapor convergence timescales. Upon network completion (early 2011), 3D water vapor field analyses and participation in the intensive field campaign GPM-CHUVA will provide unique data sets for initializing, constraining or validating high-resolution models or refining convective parameterizations. Copyright (C) 2011 Royal Meteorological SocietyFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)