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Welcome to the Marine Modeling and Analysis Branch of the Environmental Modeling Center at the National Centers for Environmental Prediction in College Park, Maryland. We are responsible for the development of improved numerical marine forecasting and analysis systems within the NOAA National Weather Service.

Operational Products

Global Real Time Ocean Forecasting System (RTOFS)

The global operational Real-Time Ocean Forecast System (Global RTOFS) at the National Centers for Environmental Prediction is based on an eddy resolving 1/12° global HYCOM (HYbrid Coordinates Ocean Model) and is part of a larger national backbone capability of ocean modeling at the National Weather Service in a strong partnership with the US Navy.

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About the Model

NOTICE: We are currently switching our model to a new supercomputer. During this time the web site graphics feed is expected to be interrupted or delayed. The production models are running normally on our supercomputer and our production FTP server and NOMADS data server are being updated. The only impact is to our post-processed graphical products displayed from this server. We apologize for the inconvenience.


A third generation wave model run four times a day (00Z, 06Z, 12Z, and 18Z). Each run starts with 9-, 6- and 3-hour hindcasts and produces forecasts of every 3 hours from the initial time out to 180 hours (84 hours for the Great Lakes).

Model Suite

Sea Ice Home Page

The Polar and Great Lakes Ice group works on sea ice analysis from satellite, sea ice modeling, and ice-atmosphere-ocean coupling. Our work supports the Alaska Region of the National Weather Service, the Great Lakes Marine Forecasting group in the Cleveland NWSFO, and other groups, as well as the Environmental Modeling Center, of which the ice group is a part.
Ice group: longer description

NCEP SST Analysis

Because there are a number of different uses for sea surface temperature analysis, a number of different analyses have been developed at NCEP. The two families are the RTG -- Real Time Global, and the OI -- Optimal Interpolation (aka Reynolds SST). The RTG analyses are aimed at weather prediction and modeling, particularly at high resolution and short range. The RTG analyses employ a 2DVAR analysis technique. The OI analyses are lower resolution and aimed more at long range weather and climate. Both have a history.

Marine Meteorology Group Products

  • Ocean Winds - Satellite Remote Sensing:
    Sensors: SSM/I and QuikSCAT
    Products: wind speeds, wind vectors, atmospheric water vapor & liquid water concentrations
  • Coastal Visibility: The lowest layer Coastal Visual Range Guidance products are provided as post-processed fields direct from the NAM (12 km resolution currently) model. The data used for the lower 48 states are taken from a 40km Lambert Conformal grid and applied to a 0.25° X 0.25° lon/lat grid over North America. The data used for Alaska are taken from a 45 km polar stereographic grid and applied to a 0.25° X 0.25° lon/lat grid over Alaska and adjacent water bodies. These fields are in meters and have been converted to nautical miles on the depictions shown on this web page.
  • Global Visibility: This guidance is based on the GFS Model output and uses a modified version of the Stoelinga and Warner algorithm used in the eta mesoscale model. The GRIB output files have output in meters from 0 - 20,000 meters. The graphical display is designed primarily for the use of mariners.
  • Vessel Icing: The NCEP superstructure ice accretion forecast system was developed by applying statistical algorithms developed by Overland and Pease at the Pacific Marine Environmental Research Laboratory in the mid-1980s. The algorithm relates icing to wind speed, freezing point of sea water, air temperature, and sea surface temperature. The method is designed for trawlers in the 20 to 75 meter length range, underway at normal speeds in open seas and not heading downwind.

Marine Archive

  • Fukushima Tracers
    NCEP/NWS deployed three-dimensional particle tracing within our Global RTOFS system to predict the long-term movement of radionuclides in the ocean shortly after the Japanese nuclear disaster near Fukushima.
  • Fukushima Surface Plume Study
    NCEP/NWS conducted a surface plume study using data from our Global RTOFS system to predict the first 100 days of movement of radionuclides in the ocean shortly after the Japanese nuclear disaster near Fukushima.

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SDM Contact Notes:
Ocean Models -- Avichal Mehra
Wave Models -- Arun Chawla

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Page last modified: Monday, 16-Dec-2019 15:59:26 UTC