Within a project of the German Research Foundation, a mobile, scanning water-vapor differential absorption lidar (DIAL) system has been developed. The system consists of four novel components: A mobile laboratory mounted on a trailer, a high-power Ti:Sapphire laser transmitter, a scanning 80-cm transceiver, and a high-speed data acquisition system.

During the World Weather Research Program (WWRP) Research and Development Project (RDP) Convective and Orographically-induced Precipitation Study (COPS) the system was operated for the first time. It will be shown that its water-vapor measurements have extraordinary resolution and accuracy. Several applications are discussed: Study of the advection of moisture ahead of a mesoscale convective system including the detection of outflow boundaries, the evolution of moisture in the convective boundary layer, and the evaluation of moisture fields in the next generation of convection permitting mesoscale models. Finally, the potential of sensor synergy with lidar and/or radar derived temperature and wind fields as well as with passive remote sensing is demonstrated.