Four smart balloons, specially instrumented with new lightweight ozone sensors, were released during the AIRMAP campaign conducted over New England and the Atlantic Ocean during July and August 2004. Smart balloons are designed and constructed at the NOAA Air Resources Laboratory Field Research Division (ARLFRD) in collaboration with the University of Hawaii. One of the goals of AIRMAP is to develop a detailed understanding of the source and evolution of persistent air pollutants over New England. All four balloons were released from Orient Point on Long Island, NY. Specifics of the balloon architecture and performance will be presented in a separate paper. The focus of this paper is the application of the NOAA/ARL Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) Model to provide guidance for balloon releases during AIRMAP. While the balloons were in flight, additional trajectory forecasts were made to predict the future path of the balloons. Finally, post trajectory simulations were undertaken using actual elevation data from the balloons to investigate how well the model is able to simulate the behavior of the balloons.