Near Shore Wave Prediction System (NWPS) Output

A major winter storm is expected to impact the area late this weekend.

A major winter storm is expected to begin impacting the area Saturday night, continuing through early Monday afternoon. Significant snow accumulations are possible areawide. Some mixed precipitation is possible across southeastern PA, southern NJ, and the Delmarva. View this briefing for details. Read More >

These models forecasts are produced by WFO Mount Holly, NJ, using the NWPS wave models and the Real Time Ocean Forecast System.

The NWPS output is used as guidance to produce WFO Mount Holly. It is only experimental and it may differ from the official forecast. For the official marine forecast graphics go to: WFO PHI Official Marine Forecast Graphics.

NWPS accounts for the following physics:

Wave propagation in time and space, shoaling, refraction due to current and depth, frequency shifting due to currents and non-stationary depth.

Wave generation by wind.

Three- and four-wave interactions.

Whitecapping, bottom friction and depth-induced breaking.

Dissipation.

Wave-induced set-up.

Propagation from laboratory up to global scales.

Transmission through and reflection (specular and diffuse) against obstacles.

Diffraction.

In here you will see 3-hourly forecast outputs for significant wave height, peak wave direction, peak wave period, and significant swell height (heights in feet and periods in seconds). Our local version of NWPS also uses input from WAVEWATCH III for boundary conditions.

NOTE: Significant Swell Height output from NWPS is the average height of the highest 1/3 of the group of waves with periods of 10 secs or longer.