Near Shore Wave Prediction System (NWPS) Output

Prolonged Atmospheric River in the Northwest; Snow in the North-Central US

A prolonged atmospheric river will bring heavy rainfall which may lead to widespread urban and river flooding, heavy mountain snow, along with gusty winds to the Pacific Northwest into the northern Rockies through much of the week. A clipper will bring a period of snow across the upper Midwest and the Great Lakes into Tuesday, before a stronger system bring more wintry impacts. 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.