The Indian River Lagoon (IRL), which extends over 175 miles north-to-south along the central east coast of Florida from Ponce de Leon Inlet to Jupiter Inlet, is a shallow estuary with limited salt water input. Because of its shallow depth and limited ocean access, wind-drive tides are general more important. The NWS Melbourne office currently uses rules of thumb to forecast wave conditions along the IRL in Brevard and Indian River counties here in Florida. The primary goal of this project is to provide the wind forcing necessary to generate ensemble hydrodynamic forecasts of set-up and set-down in the IRL for high wind events. An additional by-product of this work is an evaluation of the WRF wind forecasts.
A second Partners Project focuses on the hydrodynamic aspect of the research problem. The atmospheric component of the work consists of a one year evaluation of the Melbourne NWS archival WRF wind output (at 3 km horizontal resolution and 1 h temporal) at locations along/near the IRL that coincide with surface observations. The forecast wind errors will be used to force hydrodynamic ensembles in which permutations in the forecast wind are introduced using the composited errors. PDFs of the wind error estimates, stratified by forecast time, will be randomly sampled to generate an ensemble of forcing data sets that vary about the WRF forecast. The temporal variations will be mapped to the spatial domain though the weighting of the time dependent error by the forecast wind magnitude. The proposed forecast window of interest is on the order of 24 h. A couple of high wind events will be selected to server as a test bed for evaluation.