What Should Be Considered When Simulating Doppler Velocities Measured by Ground-Based Weather Radars?

A sophisticated and flexible simulator of Doppler velocities measured by ground-based weather radars is appended to a high-resolution nonhydrostatic atmospheric model. Sensitivity experiments are conducted by using different configurations for each of the physical processes that is modeled by the simulator. It is concluded that neglecting the vertical beam broadening effect or the weighting by reflectivities yields errors of the same order on the simulated reflectivities. Neglecting hydrometeor fall speeds has a much smaller impact. It is also shown that neglecting both the beam broadening effect and the weighting by reflectivities yields errors of the same order as occur when only one of these effects is neglected.