Two heavy precipitation events occuring in the Black Hills region were simulated using the ARPS atmospheric numerical model. The precipitation distribution at 1 Km was produced by nested numerical simulation. A land surface model was coupled with ARPS to study the effect of landscape characteristics on the distribution of precipitation and its interaction with topographical effects on the fine scale. A hydrological model was coupled with with the land surface model and ARPS to investigate the runoff and streamflow for the complex terrain of the Black Hills. Numerical simulation results and comparisons with observations will be presented. Results for the Rapid City flash flood of 9 June 1972 will also be compared with results of previous numerical simulations