Non-Hydrostatic RegCM4 (RegCM4-NH): model description and case studies over multiple domains

Abstract. We describe the development of a non-hydrostatic version regional climate model RegCM4, called RegCM4-NH, for use at convection-permitting resolutions. The dynamical core Mesoscale Model MM5 is introduced in with some modifications to increase stability and applicability long-term simulations. Newly available explicit microphysics schemes are also described, three case studies intense convection events carried out order illustrate performance model. They all run grid spacing 3 km over domains northern California, Texas Lake Victoria region, without parameterized cumulus convection. A substantial improvement found several aspects simulations compared corresponding coarser-resolution (12 km) runs completed hydrostatic employing RegCM4-NH currently being used different projects resolutions intended be resource users RegCM modeling system.