A number of cases of intense early spring sea breezes were measured by a dense mesoscale network of weather stations in the greater New York City Metropolitan Region during 1998. On several days sea breeze fronts developed just west of the New Jersey coastline and New York City that were sharpened when the prevailing southwest winds were deflected westward by the Watchung Mountains of New Jersey. The fifth generation Pennsylvania State University-NCAR Mesoscale Model version 3 (MM5) simulated these features once the warm bias of coastal waters in the objectively analyzed sea surface temperatures and surface reservoir temperatures were corrected by subjective analysis and vertical resolution was increased in the atmospheric boundary layer.