Significant improvements have recently been implemented in the COAMPS moist physics parameterization. Among these are improvements in the range of species type interactions, the adjustment to saturation, the ice nucleation and fall speed parameterizations, as well as the inclusion of drizzle and graupel. To assess the effects of these improvements, the model was run for a period of several weeks over the eastern United States. The general performance of precipitation and cloud forecasts as well as temperature relative humidity and wind errors was investigated. In-depth studies focused on the occurrence of intense mesoscale precipitation events using a new event-based verification method. Additional simulations were performed on a developing tropical cyclone in the Atlantic Ocean. Results show that the accuracy of the general precipitation forecasts was significantly improved. The tropical cyclone was also found to be more intense, and thus closer to the observed central pressure.