Interactions between the atmosphere and the land surface have considerable influences on regional and global climate variability. Therefore, coupled land-atmosphere systems that can realistically represent these interactions are critical for improving our understanding of the atmosphere-biosphere exchanges of energy, water, and their associated feedbacks. NASA's Land Information System (LIS) is a high resolution land data assimilation system that integrates the use of high resolution satellite and observational data, advanced land surface models, data assimilation techniques, and high performance computing tools. LIS has been coupled to the Weather Research and Forecasting (WRF), enabling a high-resolution land-atmosphere modeling testbed that can employ various land surface models in LIS, using different PBL, microphysics, radiation and cumulus parameterization schemes in WRF. In this study, LIS is first executed in an uncoupled manner, using different land surface models, to generate high resolution land surface fields for a case period (the 2002 International H2O project (IHOP) field program). The case day simulations performed with the land surface models in LIS demonstrate the improved skill in the mesoscale prediction induced by the fine scale, accurate representation of land surface provided by the uncoupled LIS simulations. The results also illustrate the impact of land surface heterogeneity representations on the evolution of organized convection.