ARAP s integrated suite of research, development, and operational programs is focused on the creation of capabilities for predicting the consequences of atmospheric releases of hazardous materials. The foundation of ARAP lies in its science and technology base in multi-scale meteorological and dispersion modeling, field experiments, and software systems (databases, real-time data acquisition software, and remote-access tools). Scientific and technological advancements are integrated into DOENNSA s operational National Atmospheric Release Advisory Center (NARAC) at LLNL to support emergency response, pre-event planning, preparedness, and consequence analysis. Some recent ARAP development highlights are described below.