IMPORTANT NOTICE REGARDING THE WAVEWATCH III® MULTI-1 WEBSITE
The EMC WAVEWATCH III® global wave model Multi-1 was
decommissioned in NCEP operations on March 22, 2021. It has been
replaced by a new configuration of the WAVEWATCH III global wave
model, called GFS-Wave, and coupled to the
Global Forecast System (GFSv16), as part of the
Unified Forecast System.
THIS WEBSITE IS NOT DISPLAYING MULTI-1 OR GFS-WAVE GRAPHICS
It is being maintained for archival and verification purposes only.
*under gfs.YYYYMMDD/CC/wave/gridded and gfs.YYYYMMDD/CC/wave/station
Graphics of the GFS-Wave model output will become available some time in April on the
Model Analysis and Guidance (MAG) site. Note
that the current WW3 link on that page is to a preliminary set of GFS-Wave
graphics. New graphics with more options will be added with the coming
update in May, and will be under GFS-Wave instead of WW3.
The Global Wave Ensemble System (GWES) was discontinued on 23
Sep 2020 and has been replaced by an improved GEFS-Waves,
consisting of a one-way nesting of the WAVEWATCH III system with
the recently upgraded GFS Ensemble Forecast System. The NOAA
press release on the upgrade is
here, and information on GEFS is available
The GEFSv12 Service Change Notice (issued 8/20/2020, PDF) is
here, and you can find information on the evaluation of the GEFS-Waves portion
of the GEFS system in the
Model Evaluation Group (MEG) Summary page on the
The model data is available four times a day (0, 6, 12, 18)Z from:
The grid generating software gridgenv3.0 is also available. This
updated software can now generate bathymetry, mask and obstruction
grids for rectilinear as well as curvilinear grids. To make the
functions generic significant changes have been made to the function
A portable package of scripts and Fortran code are provided to
perform genetic optimization of the free parameters of the Generalized
Multiple DIA in WAVEWATCH III. The package has been designed to work
Documentation on all of the released versions of WAVEWATCH III® can
be found under the Version Documentation and Errata tab on
WAVEWATCH III® (Tolman 1997, 1999a, 2009) is a third generation wave
model developed at NOAA/NCEP in the spirit of the WAM model (WAMDIG 1988,
Komen et al. 1994). It is a further development of the model
WAVEWATCH, as developed at Delft University of Technology (Tolman 1989, 1991a)
and WAVEWATCH II, developed at NASA, Goddard Space Flight Center (e.g., Tolman
1992). WAVEWATCH III®, however, differs from its predecessors in many
important points such as the governing equations, the model structure, the
numerical methods and the physical parameterizations. Furthermore, with model
version 3.14, WAVEWATCH III® is evolving from a wave model into a wave
modeling framework, which allows for easy development of additional physical
and numerical approaches to wave modeling.
WAVEWATCH III® solves the random phase spectral action density balance
equation for wavenumber-direction spectra. The implicit assumption of this
equation is that properties of medium (water depth and current) as well as the
wave field itself vary on time and space scales that are much larger than the
variation scales of a single wave. With version 3.14 some source term options
for extremely shallow water (surf zone) have been included, as well as wetting
and drying of grid points. Whereas the surf-zone physics implemented so far
are still fairly rudimentary, it does imply that the wave model can now be
applied to arbitrary shallow water.
The governing equations of WAVEWATCH III® include
refraction and straining of the wave field due to temporal and spatial
variations of the mean water depth and of the mean current (tides, surges
etc.), when applicable.
Parameterizations of physical processes (source terms)
include wave growth and decay due to the actions of wind, nonlinear resonant
interactions, dissipation (`whitecapping'), bottom friction, surf-breaking
(i.e., depth-induced breaking) and scattering due to wave-bottom
interactions. The model is prepared for triad interactions and is prepared for
other, as of yet undefined source terms, but the latter have not been
implemented yet. WAM cycle 4, bottom scattering,
surf zone physics and wetting/drying new in model version 3.14.
Wave propagation is considered to be linear. Relevant
nonlinear effects such as resonant interactions are, therefore, included in
the source terms (physics).
The model includes several alleviation methods for the Garden
Sprinkler Effect (Booij and Holthuijsen, 1987, Tolman, 2002c).
The model includes sub-grid representation of unresolved
islands (Tolman 2002e). A software package based on Matlab®
has been developed to automate generation of grids including
obstructions due to unresolved islands (Chawla and Tolman, 2007, 2008). Grid generation package first distributed with model
version 3.14 through model distribution web page (see below).
The model includes options for choosing various term packages,
some intended for operations, others for research. The source term packages
are selected at the compile level.
The model includes dynamically updated ice coverage.
The model is prepared for data assimilation, but no data
assimilation package is provided with the present distribution of the source
Spectral partitioning is now available for post-processing of
point output, or for the entire wave model grid using the Vincent and Soille
(1991) algorithm (Hanson and Jenssen, 2004; Hanson et al , 2006,
2009). New in model version 3.14
The model is written in ANSI standard FORTRAN 90, fully
modular and fully allocatable.
The model uses a regularly spaced longitude-latitude grid
(longitude and latitude increment do not need to be equal) and, optionally, a
The model is set up for traditional one-way nesting, where
model grids are run as separate models consecutively, starting with the models
with the lowest spatial resolution..
With model version 3.14, a `mosaic' approach is available,
where an arbitrary number of grids can be considered with full two-way
interactions between all grids, effectively making the mosaic of grids operate
as a single model with variable spatial resolution (Tolman, 2006, 2008). New in model version 3.14.
The mosaic approach introduced in version 3.14 only considers
static grids. Relocatable grids within the mosaic are being developed.
Already available in model version 3.14 is an approach where (a mosaic of
grids) moves along a user-defined path. This allows for moving grid modeling
of hurricanes away from the coast (Tolman and Alves, 2005). New in model version 3.14
Wave energy spectra are discretized using a constant
directional increment (covering all directions), and a spatially varying
wavenumber grid. The latter grid corresponds to an invariant logarithmic
intrinsic frequency grid (Tolman and Booij 1998).
Both a first order accurate and third order accurate numerical
scheme are available to describe wave propagation (Tolman 1995). The
propagation scheme is selected at the compile level.
The source terms are integrated in time using a dynamically
adjusted time stepping algorithm, which concentrates computational efforts in
conditions with rapid spectral changes (Tolman 1992, 1997, 1999a, 2009).
The model can optionally be compiled to include shared memory
parallelisms using OpenMP compiler directives.
The model can optionally be compiled for a distributed memory
environment using the Message Passing Interface (MPI, see Tolman 2002a).
Gridded fields of 31 input and mean wave parameters such as
the significant wave height, directions, frequencies etc. Up from 18 in model version 2.22
Output of wave spectra at selected locations.
Output of wave spectra along arbitrary tracks.
Up to 9 restart files per model run.
Files with boundary data for up to 9 separate nested runs in a
one-way nested model approach where models are run independently. In the
mosaic approach, input boundary data for each grid in the mosaic can be dumped
for later use.
Partitioned wave field information is available for the full
model grid or sub-sets and sub-sampled grids.
New in model version 3.14.
The model provides binary or ASCII output, as well as output
for the GrADS graphics package by means of post processing. Postprocessors
for GRIB data are available, but will require GRIB packing libraries.
Version Documentation and Errata
The documentation of WAVEWATCH III® is available on line in pdf
files. For each released model version an errata page is maintained, which is
the sole source of distributing errors and fixes of the model. To receive
information on model changes etc, subscribe to the
MMAB mailing list.
Model v 5.16 is the new public release of WAVEWATCH III. There
have been upgrades to the modeling system since the last public
release (v 4.18). WAVEWATCH III transitioned from an NCEP model to a
community driven effort with developers spanning several organizations.
Model development is done using a subversion server which is housed at
Preparing for next model version, adding optional instrumentation to
code for profiling of memory use (model version 5.00).
Optimization of IC3 (ice source function). Added non-dispersive variant
of "turbulence under ice" ice source function to IC2. This is simpler than
the existing version and requires fewer free parameters. Method is selected
by the user. Added fluxes for momentum and energy associated with ice source
functions. Preliminary scheme for scattering of waves by ice (model version 5.01).
Revisiting OpenMP parallelisms in the model. Revising previous OpenMP-only
approach and introducing Hybrid MPI-OpenMP approach initiated by Farid Parpia
of IBM (model version 5.02).
Implementing tripole grid functionality for first order scheme, and for
gradient calculations (e.g. for refraction by depth/current gradients). Adding
test case for tripole grid to regtests (model version 5.03).
Adding capability to handle cpp macros (model version 5.04).
Upgrade to ST6 physics (model version 5.05).
Adding the NCEP coupler capability (model version 5.06).
Adding OASIS coupler capability (model version 5.07).
Series of bug fix updates (model version 5.08).
Updates to SMC grid type (model version 5.09).
Adding sea ice scattering and creep dissipation source terms (model version 5.10).
Introducing namelists formats for input files. Traditional way of providing
inputs is still possible using the inp suffix (model version 5.11).
Sea-state dependent stress-calculations are added. Updates to the restart
files related to file size and optimization of initialization from restart files.
Note, this means restart files are not backwards compatible (model version 5.12).
Adding TSA as a nonlinear wave-wave interaction source term option (model version 5.13).
Adding the capability for calculating space-time extremes (model version 5.14).
Optimization of wvae system tracking (model version 5.15).
Final preparations for distribution (model version 5.16).
Our grid generating software gridgenv3.0 is available to generate bathymetry,
mask and obstruction grids for rectilinear as well as curvilinear grids. A portable
package of scripts and Fortran code are provided to perform genetic optimization of
the free parameters of the Generalized Multiple DIA in WAVEWATCH III.
Model version 4.18
Model v 4.18 is the new public release of WAVEWATCH III. There
have been significant upgrades to the modeling system since the last
public release (v 3.14). WAVEWATCH III has now transitioned from an
NCEP model to a community driven effort with developers spanning
several organizations. Model development is done using a subversion
server which is housed at NCEP.
Model version 4.00 was used as a set-up for the new version. The
only main modification of this version of the code is removing the
XYG and LLG switches, and replacing the choice of grid with a keyword
in the code and in mod def.ww3.
Adding curvilinear grids from Rogers and Campbell (2009) (model
Adding unstructured grids from Roland (2009) (model version
Adding new output fields (model versions 4.03 and 4.11).
Adding Ardhuin et al. (2010) source term package, and SHOWEX bottom
friction source term (model version 4.04)
Adding iceberg blocking (model version 4.05).
Adding NetCDF output post-processing (model version
Adding formal regression testing for model developers, adopted from
previously undistributed NRL ‘nrltest’ directory (model version
Adding GMD and nonlinear filter (model version 4.08).
Adding wave system tracking (model version 4.09).
Adding regular grid splitting tools (model version 4.10).
Adding second order UNO schemes (model version 4.12).
Adding SMC grid and rotated grid options (model version
BYDRZ source term package (model version 4.14).
Mud-ice interactions (model version 4.15).
Infra-gravity wave module (model version 4.16).
Triad interactions (model version 4.17).
Final preparations for distribution (model version 4.18).
We are also releasing a new version of our grid generating
software gridgenv2.0. This updated software can now generate
bathymetry, mask and obstruction grids for rectilinear as well as
curvilinear grids. To make the functions generic significant changes
have been made to the function calls.
A portable package of scripts and Fortran code are provided
to perform genetic optimization of the free parameters of the
Generalized Multiple DIA in WAVEWATCH III. The package has been
designed to work with v4.18
Model version 1.15
Tolman , H. L, 1997: User manual and system documentation of
WAVEWATCH-III version 1.15. NOAA / NWS / NCEP / OMB Technical Note 151,
97 pp. (0.74MB PDF file). The
source code of this model has never been distributed.
Model version 1.18:
Tolman , H. L, 1999a: User manual and system documentation of
WAVEWATCH-III version 1.18. NOAA / NWS / NCEP / OMB Technical Note 166
, 110 pp. (0.76MB PDF
Tolman , H. L, 1999b: WAVEWATCH-III version 1.18: Generating
GRIB files. NOAA / NWS / NCEP / OMB Technical Note 167, 7 pp. (0.15MB PDF file)
Tolman , H. L, 1999c: WAVEWATCH-III version 1.18:
Post-processing using NCAR graphics. NOAA / NWS / NCEP / OMB Technical Note
168, 9 pp. (0.15MB PDF
The latest release (currently at 6.07) 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
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
If you are a developer and would like to add a new feature
to the code, see the
WW3 GitHub wiki hosts a description
of the model, its main features, output options, user
and developer guides, technical documentation and latest news.
Model versions 3.14 through 5.16 were distributed under an
open source style license, through
a password protected distribution site. Those granted usernames and passwords may
still access these versions of the code this way:
Download the Source code
The model is subject to continuous development. The following new features are
presently being incorporated in WAVEWATCH III® at NCEP and by our
partners, or are considered for incorporation in the future.
Unifying Cartesian and spherical grid approaches, and
expanding to curvilinear grids (NRL Stennis).
Unstructured grid options (developed at SHOM, method of Aron
Relocatable grids in mosaic approach (NCEP).
Alternative propagation schemes (second order scheme from
Expanded list of output parameters, particularly for model
ESMF wrapper to facilitate model coupling (NRL Stennis),
Alternative source term parameterizations (many from NOPP
projects and others).
New GSE alleviation (NCEP).
Quasi-steady model integration compatable with SWAN approach (NCEP).
New releases will generally become available after implementation of a new
model version at NCEP. Research model versions may be made available to those
interested in and committed to basic model development. Contact NCEP.EMC.wavewatch@NOAA.gov for
requests to get access to the research versions of the model.
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Chawla, A. and H. L. Tolman, 2008: Obstruction grids for wave
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Hanson, J. L. and R. E. Jensen, 2004: Wave system diagnostics
for numerical wave models. In 8th International
Workshop on Wave Hindcasting and Forecasting, JCOMM Tech. Rep. 29,
Hanson, J.L., B. A. Tracy, H. L. Tolman and D. Scott, 2006:
Pacific hindcast performance evaluation of three numerical wave models. in
9th International Workshop on Wave Hindcasting and
Forecasting, JCOMM Tech.Rep.34. Paper A2.
Hanson, J. L., B. A. Tracy, H. L. Tolman and R. D. Scott, 2009:
Pacific hindcast performance of three numerical wave models,
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for a spectral wind wave model. NWS/NCEP Office Note 411, 30 pp. +
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1.15. NOAA / NWS / NCEP / OMB Technical Note 151, 97 pp. (0.74MB PDF
Tolman, H. L.,
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