A comparison of the two MM5 land surface models (LSM) was performed to understand the importance of land surface processes and land atmosphere interactions in the evolution of mesoscale and synoptic scale weather phenomena during Tropical Storm Allison's (2001) movement through North Carolina from 15 June through 18 June 2001. A triple-nested version of fifth generation PSU-NCAR Mesoscale Model (MM5) was employed to study the boundary layer structure and precipitation patterns of Tropical Storm Allison. Two sets of simulations were performed. The first employed the Oregon State University (OSU) land surface model (LSM) coupled with the MRF PBL scheme, while the second simulation was completed using the Pleim Xiu (PX) land surface model with asymmetric convective model (ACM). Three nests (with 5- 15- and 45- km grid spacing) with one-way interaction between the respective domains were used. Both model simulations were integrated up to a period of 72h until 00 UTC 18 June 2001. Model results from the two simulations were compared with several surface and remote sensed observations and analysis. Results from this study suggest that (i) the model results are sensitive to the land surface model / land atmosphere interaction scheme within MM5 even for synoptically driven events such as tropical storms; (ii) the MM5 model coupled with the Oregon State University LSM is significantly more accurate in simulating the mesoscale and boundary layer features associated with Tropical Storm Allison over North Carolina than the MM5 coupled with the PX LSM; (iii) land atmosphere interactions are critical in determining the structure and dynamics of both mesoscale and synoptic scale weather phenomena.