Two NASA-developed tools - the Dynamic Weather Routes (DWR) tool and a national implementation of DWR called the National Airspace System Constraint Evaluation and Notification Tool (NASCENT) - will help pilots identify and evaluate opportunities for more efficient paths around convective weather and other airspace constraints. Dave McNally and Kapil Sheth are the lead developers of the technologies. DWR was tested operationally by a major US airline for three years.