In Part I of this two part paper, we discuss the historical improvements in NCEP's hurricane model suite, composed of the Global Forecast System (GFS) and the GFDL high resolution, regional hurricane model. Each of these models has been through a constantly improving evolution over the past 5 years, with resulting steady improvements in seasonal forecast track and intensity forecast statistics. Improvements have stemmed from changes to vortex initialization in the GFS, upgrades to GFS physics, and improved assimilation of an increasing variety of observations. Upgrades to the GFDL model in 2003 included adoption of the GFS cumulus and boundary layer physics, and improvements to the coupled ocean model. The steadily improving forecast statistics have been seen in both the Atlantic and East Pacific basins. The impacts on forecast precipitation and intensity with experimental model and initialization will also be shown.