NOAA Web Site Link Tides and Currents Home Page Transparent placeholder image

On Tuesday, September 27th, 2016 beginning at 7:00 a.m. EDT, there will be system maintenance performed affecting the Tides and Currents web site ( During this time, Tides and Currents will be running on the backup website with limited capability. Click here for more information.

Disclaimers - Center for Operational Oceanographic Products and Services (CO-OPS)

Raw Data Disclaimer

These raw data have not been subjected to the National Ocean Service's quality control or quality assurance procedures and do not meet the criteria and standards of official National Ocean Service data. They are released for limited public use as preliminary data to be used only with appropriate caution.

External Links

Any links to non-government websites contained on this website or any sites operated by the Center for Operational Oceanographic Products and Services (CO-OPS) are not an endorsement of said external sites, products, or entities.

Operational Forecast Systems (OFS) Disclaimer

Nature of OFS Products

The Operational Forecast Systems (OFS) have been created by NOAA/NOS to provide the maritime community with improved short-term predictions of physical characteristics, such as water levels, currents, water temperatures and salinities, in specific estuaries. Please be advised that these predictions are based on hydrodynamic models and, as such, should be considered as computer-generated forecast guidance.

OFSs run a numerical model several times a day (the nowcast) to simulate water levels and four times a day (the forecast) to produce a short-term forecast of estuarine water levels. The model is an improvement over the Tide Tables, which use only historical data to predict the tides. In addition to the tides, the model includes water level deviations in the estuaries caused by wind and ocean water level changes. National Weather Service forecast models provide predicted wind and ocean water level allowing the model to make predictions of water level and current velocity changes in the Bay for the near future, currently between one and two days. However, the wind and ocean water level forecasts are limited in their accuracy beyond one to two days, thus tide table predictions are probably better for longer term predictions.

The OFS water level nowcasts and forecasts are accurate to within 6 inches 90% of the time. Occasional very large high or low water level events may cause greater errors. Even during extreme events the timing and tendency toward water level rise or fall are often correct, although the amplitude of the error may be greater than 6 inches. A detailed analysis of the accuracy of the OFSs can be found on this web site in the OFS skill assessment documents.

Use of Data and Products

The information on government servers are in the public domain, unless specifically annotated otherwise, and may be used freely by the public. Before using information obtained from this server, special attention should be given to the date and time of the data and products being displayed. This information shall not be modified in content and then presented as official government material.

The user assumes the entire risk related to its use of these data. NOS is providing these data "as is," and NOS disclaims any and all warranties, whether express or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose. In no event will NOS be liable to you or to any third party for any direct, indirect, incidental, consequential, special or exemplary damages or lost profit resulting from any use or misuse of this data.

NOS requests that attribution be given whenever NOS material is reproduced and re-disseminated. Pursuant to 17 U.S.C. 403, third parties producing copyrighted (compilation) works consisting predominantly of material created by Federal Government employees are encouraged to provide notice with such work(s) identifying the U.S. Government material incorporated and stating that such material is not subject to copyright protection.

Revised: 10/15/2013
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services