Evaluation of National Weather Service and Extramural Water Level Forecast Guidance from Real Time Ocean Forecast Systems.

摘要

The water level guidance, both subtidal and total, from National Weather Service (NWS) and extramural real-time oceanographic forecast modeling systems were compared to 24 National Ocean Service (NOS) water level stations on the U.S. East Coast and along the Gulf of Mexico shoreline. The National Weather Service (NWS) Real Time Ocean Forecast System (RTOFS), NWS Extra- Tropical Storm Surge (ETSS) Model, United States Navy (USN) global Navy Coupled Ocean Model (G-NCOM), and University of North Carolina (UNC) Western North Atlantic Forecast System Advanced Circulation (ADCIRC) Model water level forecasts were compared with the observations during November 2008. Because the ETSS model is subtidal, the ETSS forecast water levels were compared with observed subtidal water levels. The observed subtidal water levels were obtained using a 30 hour low pass Fourier filter. Because the RTOFS, ADCIRC, and G-NCOM includes tides, their forecast water levels were compared with the total observed water level. Two new versions of RTOFS were considered and contrasted with the previous RTOFS results documented in Richardson and Schmalz (2007). Using the ADCIRC nowcast water levels, it was possible to perform a harmonic analysis as well as a subtidal comparison with subtidal observed water levels. Since G-NCOM included tides, subtidal results were obtained by subtraction of the NOS predicted astronomic tide from the total nowcast water level (detiding).