Coastal & Offshore Wave
Height Forecasts

CDIP's coastal wave height forecasts are actually the combined result of two wave models:

The NOAA/NCEP implementation of the Wavewatch III wave model for deep water regions (depth > 300m). The Wavewatch III model is a wind-wave generation and propagation model. That is, the global wave forecasts are made based on global surface wind forecasts.

The Coastal Data Information Program's implementation of a spectral refraction-diffraction wave model for shallow water (10m < depth < 300m). It models the effect of bathymetry on waves as they travel from deep water towards the coast. This implementation is slightly different than the swell version. We also include the propagation (but not generation) of shorter period local seas based on input from the Wavewatch III model.
  • Offshore Wave Height Plot

    This is the plot displayed at the top of the page. It shows forecasted significant wave heights from the NOAA/NCEP Wavewatch III model for the two deep water sites off California used in the coastal wave models. The plot is designed to provide a quick look at whether there is a big deep water wave event on the horizon that may impact the coastline. The storm threshold line of approximately 13 ft. is based on historical storms in southern California, although forecasts of offshore waves exceeding this threshold do not necessarily mean damaging coastal waves will occur.

  • Coastal Wave Height Plot

    This plot is similar to CDIP's real-time swell predictions of alongcoast wave height. It is a plot of the model results along the 10m depth contour. They are not breaking wave heights; generally, the 10m depth contour is outside the surf zone. Nevertheless, it does provide an idea of how much wave energy is reaching the coast relative to other locations. Higher wave energy generally leads to higher water levels and wave runup at the adjacent shore.

Visit our website at ...