A new approach for parameterizing microphysics based on prediction of ice particle properties
A bulk scheme based on the new approach has been developed and implemented into the Weather Research and Forecasting model (WRF). The initial development combines the four prognosed ice variables with the standard two-moment approach prognosing number and mass mixing ratios for cloud water and rain. The new scheme is tested in WRF at high-resolution “convection-permitting” scales over a wide range of conditions including winter orographic precipitation and different types of convective storms. Results are compared to observations and simulations using other bulk microphysics schemes in WRF. Despite the simplicity of the new scheme, i.e., use of a single ice category, its prediction of ice particle properties produces realistic simulation of meteorological phenomena at a reduced computational cost relative to most current schemes. Thus, the new scheme shows promise for use in both operational and research NWP models.