The Quick Urban & Industrial Complex (QUIC) dispersion modeling system is evaluated using street-level wind and concentration measurements taken during the Joint Urban 2003 Field Experiment held in downtown Oklahoma City. The Lagrangian random walk dispersion model QUIC-Plume is run using a 3D mean velocity field obtained from two different fast running urban wind models: the empirical QUIC-URB model and a simplified computational fluid dynamics model QUIC-CFD. The street-level wind measurements and dispersion patterns using these two different flow fields are compared and analyzed. (LLNL-ABS-492322)