The Fleet Numerical Meteorology and Oceanography Center (FNMOC) Global Hybrid Coordinate Ocean Model (HYCOM)

HYCOM regions. Regions that we serve have their names on a dark background.

The Fleet Numerical Meteorology and Oceanography Center (FNMOC) global-scale operational ocean prediction system is based on the Hybrid Coordinate Ocean Model (HYCOM). This system provides 4-day forecasts at 3-hour time steps, updated at 00Z daily. Navy Global HYCOM has a resolution of 1/12 degree in the horizontal and uses hybrid (isopycnal/sigma/z-level) coordinates in the vertical. The output is interpolated onto a regular 1/12-degree grid horizontally and 40 standard depth levels. The NetCDF files contain ocean temperature, salinity, eastward and northward currents, and elevation. Navy Global HYCOM assimilates satellite altimeter observations, satellite and in situ sea surface temperature, as well as available in situ vertical temperature and salinity profiles from XBTs, ARGO floats, and moored buoys, using the NRL-developed Navy Coupled Ocean Data Assimilation (NCODA) system. Navy Global HYCOM provides boundary conditions to Navy regional models, including the AMSEAS and USEAST models available on this site. This modeling system is also run by NOAA, with different atmospheric forcing, as the Global Real-Time Ocean Forecast System (Global RTOFS).

Note: Users requiring operational, 24/7/365 access to updates of this product should consider using the high-availability servers at the National Centers for Environmental Prediction (NCEP). While these servers don't have Navy HYCOM directly, they provide access to Global RTOFS data, which is derived from HYCOM, at the Global RTOFS High Resolution Ocean Model page. This data, along with other ocean products are available on the Ocean Prediction Center page.