The initial control simulation of Typhoon Sinlaku produced a relatively accurate track with the exception of an excessive southward deflection upstream of the island, possibly due to the model underestimating the intensity of the storm. This small upstream track error resulted in very large QPF errors between the simulated and observed tracks. When the topography of Taiwan was reduced and eventually removed, the amount of southward deflection lessened and the storm began to recurve upstream of the island. The precipitation amounts over land were greatly reduced due to both the decrease in upslope forcing and the strongest pre-existing convection to the right of Sinlaku's track failing to make landfall. Since Typhoon Jangmi passed over the same area as Sinlaku a short time later, ocean surface processes were important upstream of Taiwan. The effect of terrain on Jangmi's track was less dramatic, but did produce significant differences, especially after the storm had passed over the island. The findings from these two cases are compared to preliminary results from simulations of the record-setting Typhoon Morakot which produced significantly more precipitation and flooding in the season after TCS-08.