Microphysics parameterization schemes used in numerical storm models vary greatly in complexity. One of the ways in which these schemes vary is in the number of microphysical moments that they predict for each of the hydrometeor categories included in the scheme. This study analyzed the effects of enabling prediction of a second microphysical moment, number concentration, for each hydrometeor category in a mixed phase, bulk microphysics scheme. The addition of number concentration prediction for cloud droplets was found to have a large influence on the early development of the simulated storm, while the addition of number concentration prediction for rain was found to have the largest impact on the storm’s reflectivity structure. The electrification of the storm was also found to be quite sensitive to changes in the microphysics complexity, due at least in part to variations in cloud ice and graupel production in the different model runs.