A Tampa Bay coastal ocean model (TBCOM) nowcast/forecast system

Abstract

As a partially mixed estuary, Tampa Bay is influenced both by its connections to the adjacent Gulf of Mexico (GOM) and what occurs locally within the estuary. To assist in addressing the many scientific questions arising from various environmental factors, a very high resolution Tampa Bay Coastal Ocean Model (TBCOM) is modified to downscale from the deep GOM, across the continental shelf and into Tampa Bay to provide daily, automated nowcasts and forecasts. Veracity tests are provided for sea levels and currents forced by tides, synoptic weather variations and for extreme events. The model is also demonstrated to reproduce the net estuarine circulation through comparisons between in situ observations and model simulations. With demonstrated accuracy, TBCOM forecast sea levels are provided online as a reference for navigation support and for extreme events such as hurricane storm surge. Model simulations, even with a perfect model, are subject to errors by the forcing functions. For Tampa Bay, the NOAA NAM winds used to force the model are found to underestimate the actual winds, suggesting that additional wind observations for assimilation into operational weather forecast models may offer further improvements. This finding highlights the need for further coordination between coastal ocean observing systems and the ocean and atmosphere modeling communities. With coastal ocean and estuary material properties determined largely by the circulation, most ecological applications require accurate and timely circulation information, which the TBCOM Nowcast/Forecast System for Tampa Bay endeavors to provide.