Environmental Modeling Center Environmental Modeling Center Environmental Modeling Center United States Department of Commerce

EMC Operational Wave Models

The content provided on this page supports model development. These are not official NWS products and should not be relied upon for operational purposes. This web site is not subject to 24/7 support, and thus may be unavailable during system outages.

Operationally generated graphics of the wave fields (no spectra or source terms) are available from Model Analyses and Guidance.

Bulletin files are available from the Production FTP/HTTPS server. Look for gfs.YYYYMMDD/CC/wave/station/bulls.tCCz/gfswave.stationID.bull

The EMC suite of operational ocean wave models are based on the wave model WAVEWATCH III® using operational NCEP products as input.

Global Forecast System - Wave

The model is run four times a day: 00Z, 06Z, 12Z, and 18Z. Each run produces forecasts of every hour from the initial time out to 120 hours, and then forecasts at 3-hour intervals out to 384 hours (this website only offers data out to 240 hours).

The global wave model consists of global and regional nested grids. As background information, a list of selected references and a chronological list of model changes are available. Finally, validation data are available for the production model.

Global Ensemble Forecast System - Wave

The Global Ensemble Forecast System - Wave (GEFS-Wave) is a one-way coupling of the GEFS atmospheric model with the WAVEWATCH III wave model. This allows for an increase in frequency of the wind forcing from 3 hours to 1 hour. This unified system has 30 members and the wave model is initialized with the previous member's 6 hour forecast. The wave model has a spatial resolution of 0.25 x 0.25 degrees. The system runs four cycles per day (00, 06, 12 and 18Z). The wave forecast has been extended from 10 to 16 days.

More information on the GEFS system is available here.

Great Lakes Waves

The model is 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 84 hours.

The Great Lakes wave model consists of a single unstructured grid. As background information, a list of selected references and a chronological list of model changes are available.

Hindcast and Reanalysis Archives

There are two classes of WAVEWATCH III® hindcasts.

  • A thirty-year hindcast generated from the NCEP Climate Forecast System Reanalysis and Reforecast (CFSRR) homogeneous dataset of hourly high-resolution winds. The time period covers from 1979 through 2009. This is a true hindcast generated with a single version of the model and a statistically consistent forcing wind field, and is suitable for use in climate studies.
  • A data set produced by rerunning the model from the operational wind fields to produce best-estimate nowcast datasets for the period Feb 2005 through May 2019. This is a statistically inhomogeneous hindcast data set, because the underlying models are periodically updated. Therefore this data set should not be used for climate studies.

Detailed descriptions of the hindcasts and reanalyses, with links to the datasets, validation statistics from buoy match-ups, and visualizations of the model data fields, can be found in the WAVEWATCH III® Hindcast and Reanalysis Archives

WAVEWATCH III® Model Description and GitHub Repository

We have moved to an open development paradigm using GitHub, which means users and developers are no longer required to submit requests for usernames and passwords to access our software package.

The WAVEWATCH III® project page is here.

The latest release is available as a compressed tarball or zipfile from the project page.

To help users and developers navigate the new repositories, we have created two sets of guidelines in GitHub to help you navigate our community modeling framework, one for users and the other for developers:

  • If you are a user and would like to access the code for applications and do not plan to engage in development work, see the User Guide.

  • If you are a developer and would like to add a new feature to the code, see the Developer Guide.

The WW3 GitHub wiki hosts a description of the model, its main features, output options, user and developer guides, technical documentation and latest news.


Two COMET modules are available regarding WAVEWATCH III® and analysis of ocean swell:

Registration is free for the courses.


While GFS-Wave, GEFS-Wave, and the Great Lakes Wave are operational models, we cannot guarantee the timeliness or accuracy of the model data and figures offered on this site. Please see our disclaimer for more information.