Model:

Updated:

Update monthly

Greenwich Mean Time:

12:00 UTC = 14:00 CEST

Resolution:

0.2° x 0.2° for Mediterranean
1° x 1° for Rest of World

Parameter:

Significant wave heights

Description:

The significant wave height is a commonly used statistical measure for the wave height, and closely corresponds to what a trained observer would consider to be the mean wave height. Note that the highest wave height of an individual wave will be significantly larger. The peak period is not commonly presented. The wave field generally consists of a set of individual wave fields. The peak period identifies either the locally generated "wind sea" (in cases with strong local winds) or the dominant wave system ("swell") that is generated elsewhere. Note that the peak period field shows discontinuities. These discontinuities can loosely be interpreted as swell fronts, although in reality many swell systems overlap at most locations and times (see spectra below).

NWW3:

The NOAA WAVEWATCH III™ operational wave model suite consists of a set of five wave models, based on version 2.22 of WAVEWATCH III™. All models use the default settings of WAVEWATCH III™ unless specified differently.

1. The global NWW3 model
2. The regional Alaskan Waters (AKW) model
3. The regional Western North Atlantic (WNA) model
4. The regional North Atlantic Hurricane (NAH) model
5. The regional Eastern North Pacific (ENP) model
6. The regional North Pacific Hurricane (NPH) model

All regional models obtain hourly boundary data from the global model. All models are run on the 00z, 06z, 12z and 18z model cycles, and start with a 6h hindcast to assure continuity of swell. All models provides 126 hour forecasts, with the exception of the NAH model (72 hour forecast). No wave data assimilation is performed. All models are based on shallow water physics without mean currents. Additional model information is provided in the table and bullets below. The four time steps are the global step, propagation step for longest wave, refraction step and minimum source term step.

Introduction to seasonal forecasting:

The production of seasonal forecasts, also known as seasonal climate forecasts, has undergone a huge transformation in the last few decades: from a purely academic and research exercise in the early '90s to the current situation where several meteorological forecast services, throughout the world, conduct routine operational seasonal forecasting activities. Such activities are devoted to providing estimates of statistics of weather on monthly and seasonal time scales, which places them somewhere between conventional weather forecasts and climate predictions.
 
In that sense, even though seasonal forecasts share some methods and tools with weather forecasting, they are part of a different paradigm which requires treating them in a different way. Instead of trying to answer to the question "how is the weather going to look like on a particular location in an specific day?", seasonal forecasts will tell us how likely it is that the coming season will be wetter, drier, warmer or colder than 'usual' for that time of year. This kind of long term predictions are feasible due to the behaviour of some of the Earth system components which evolve more slowly than the atmosphere (e.g. the ocean, the cryosphere) and in a predictable fashion, so their influence on the atmosphere can add a noticeable signal.
©Copernicus