National Weather Service United States Department of Commerce

The NWS, through this experimental product, will now provide wave height, period, and direction in the Coastal Waters Forecast (CWF). Currently, some Weather Forecast Offices (WFOs) only provide significant wave height, while others only provide wind wave and swell, creating inconsistencies.  The Experimental CWF Wave Component Update will enable NWS WFOs to provide enhanced wave information.  For more information on this experimental product see the Product Description Document. We are seeking feedback on this over the next several months, so please send us your input via this user survey

Click image to see project video


On the map below, you can scroll left or right or up and down to show all of the participating offices; then zoom and click on an area of interest (different offices represented by different colors). Click on the image in the popup to see that particular office's experimental coastal waters forecast with enhanced information. There are also links to the experimental coastal waters forecast from participating offices at the bottom of the page. 


Below is a comparison of current NWS coastal waters forecast (black) and an enhanced coastal waters forecast (blue) with detailed wave information.

Original Coastal Waters Forecast New Coastal Waters Forecast with Wave Detail
Additional Information

There are three fundamental properties of ocean waves: height, period, and direction. Wave height generally refers to how tall a wave is from trough to crest, wave direction is the direction the wave is coming from, and wave period is the time it takes for successive waves to pass a fixed point, such as a buoy. The period is also directly related to how fast waves move, how deep they extend into the ocean, how much energy they contain, which, in turn, influences the size of breaking waves at the coast, and more. 

In addition, it is common for there to be multiple, coexisting wave groups that coincide at any given point in the ocean. Some users may only be interested in short period waves because they present hazardous, choppy waves for smaller boats, others may take particular interest in the long period waves given the shoaling hazards they create near shore, while others may be interested in both.  The point is, no two wave systems are created equal, any wave system present may be hazardous or of interest to different marine groups, and therefore we feel we should not ignore them.

Currently, some Weather Forecast Offices (WFOs) only provide significant wave height, while others only provide wind wave and swell, creating inconsistencies. “Significant Wave Heights” is the average height of the highest one third of all waves at a particular point or region in the ocean. Significant Wave Height is a fundamental variable of the sea state that our customers are used to seeing, and also something very accessible from buoys to help gauge the current sea state and the accuracy of a forecast. As such, the proposed Coastal Waters Forecasts maintains that variable, but also supplements it with wave detail as described above and provided in forecast. Click on the links below to go to a participating office's experimental coastal waters forecast wave component update webpage.


Participating Weather Forecast Offices
Office Link
Boston, MA
Caribou, ME 
Charleston, SC
Corpus Christi, TX
Eureka, CA
Miami, FL
Honolulu, HI
Mobile, AL
Morehead City, NC
Mount Holly, NJ
Portland, OR
San Diego, CA
San Francisco, CA
Upton, NY
Wakefield, VA 
Wilmington, NC