This paper investigates stochastic separated flow (SSF) models used to predict particle dispersion in turbulent flows. A new model is presented that incorporates a temporal and spatial autocorrelation in the description of the fluctuating component of the turbulent gas-phase velocity. This model and four SSF models available in the literature are evaluated by comparing predictions with the grid-generated turbulence experiments of Snyder and Lumley (Snyder, W. H.; Lumley, J. L. J. Fluid Mech. 1971, 48, 41-71) and Wells and Stock (Wells, M. R.; Stock, D. E. J. Fluid Mech. 1983, 136, 31-62). Results are discussed and deficiencies in the models are explored. The new model presented herein accounts for the crossing trajectory effect with the inclusion of a spatial correlation based on the relative velocity of the particle and the time step employed. Promising results are obtained using this method.