Redetermining the tidal current predictions for the Hudson River, NY

The National Oceanic and Atmospheric Administration´s (NOAA) Center for Operational Oceanographic Products and Services (CO-OPS) collects and distributes observations and predictions of water levels and currents to ensure safe, efficient and environmentally sound maritime commerce. The CO-OPS National Current Observation Program (NCOP) is responsible for updating and maintaining the accuracy of the Tidal Current Prediction Tables. In 2003, CO-OPS updated the tidal current reference station for The Narrows (at the mouth of New York Harbor), which controls over 75 secondary stations, including the entire stretch of the Hudson River. This critical reference station had not been updated by NOAA in over 70 years. With the installation of the New York/New Jersey Harbor Physical Oceanographic Real-Time System (PORTS®), new current meter data were available to update the tidal current tables. Soon after the updates to the tables were published, CO-OPS received inquiries from local pilots about possible discrepancies in the tidal current predictions along the Hudson River. In response to users9 concerns, CO-OPS resurveyed one location in the Hudson River, near Haverstraw, NY. Comparisons between these newly-collected data and historical data were performed, and the analysis revealed up to one hour differences in the timing of the flood current. With this new information, and the fact that most of the stations along the Hudson River are based on data collected more than 40 years ago, CO-OPS has committed to resurveying the Hudson River, from Manhattan to Troy, commencing the summer of 2005.