The physics in a numerical weather prediction model play a key role in determining how the model forecasts behave for a given weather system. The Hurricane Weather Research and Forecasting (HWRF) model has been designed to predict tropical cyclones and its physics packages have been selected after rigorous testing over a large storm data base. However, the availability of multiple physics packages for HWRF allows for continued and extended testing and evaluation to assess their impact on tropical storm forecasting, leading to their potential use in research and operations. Recognizing the need of having more physics schemes available for HWRF, the Developmental Testbed Center (DTC) is working in an interoperability project to connect more parameterizations already available in the WRF model to HWRF. The impact of different physics packages on HWRF tropical cyclone forecasts will be investigated in case studies. Detailed diagnostic studies including planetary boundary layer profiles, storm structure along with impacts on track and intensity will be presented. The YSU and the MYJ PBL schemes are being tested for possible improvement over the operational HWRF configuration and the results will be shown for some cases. The large scale features, which generally dictate the track forecasts, will be compared to analysis to get some insight into the model's behavior in forecasting the storm.