One of the major research interests of the U. S. Weather Research Program is landfalling hurricanes. Regional-scale models have already been shown to have some skill at simulating hurricanes at relatively high resolution (~4-6 km). Since such high-resolution simulations require prediction of grid-resolvable cloud and precipitation fields, it is worthwhile to explore the impacts of ice microphysical processes in hurricane simulations. In particular, how do different microphysical schemes, or even variations in the assumed parameters (size distributions, particle densities, fall speeds, etc.) within a given scheme, impact the structure and evolution of simulated hurricanes? These issues will be examined through numerical simulations of Hurricane Bob (1991) using the MM5 mesoscale model and with results from idealized two-dimensional simulations with an axisymmetric model