Some precipitation anomalies in and around major urban centers have been attributed to dynamic processes such as warm air updrafts induced by urban heat island events and to microphysical processes affected by the release of natural and anthropogenic aerosols that affect atmospheric water balance. Both factors must be analyzed in order to fully understand the role urban environments may have on such precipitation anomalies over cities. The research presented here is directed towards improving our understanding of how aerosols affect cloud processes and precipitation over complex coastal urban environments such as New York City (NYC). To achieve this goal a series of atmospheric model simulations, complemented with aerosol observations and surface weather station precipitation data for NYC and northern New Jersey, are configured. Aerosol particle size distributions (PSD) obtained via NASA's AERONET Sunphotometer network are ingested into a cloud-resolving atmospheric model, the Regional Atmospheric Modeling System (RAMS), to determine the effect of varying aerosol PSD and concentration on simulated precipitation amounts. Model simulations driven with high concentrations of fine mode particles and low concentrations of coarse mode particles (HCFM-LCCM), and with low concentrations of fine mode particles and high concentrations of coarse mode particles (LCFM-HCCM), were compared to determine how each set of PSD affects precipitation totals. The effect of land use on precipitation over the region is also tested to discern urban convection effects. The analyses were completed for 11 and 18 July 2007, which represent a localized precipitation event and a Mesoscale Convective Complex, respectively. Model results suggest that RAMS precipitation results are sensitive to both PSD and land use variations.