U.S. East-Coast Shoreline Wave Climate during Intense Hurricane Forcing: Landfall Case Studies from 2016-2019

Eric Terrill1, James Behrens1, Sophia Merrifield1, Corey Olfe2, Randy Bucciarelli3, Allison Ho1, Mark A Merrifield1, Ty Hesser4 and Robert E Jensen5, (1)University of California San Diego, Scripps Institution of Oceanography, La Jolla, CA, United States, (2)University of California San Diego, Scripps Institution of Oceanography, La Jolla, United States, (3)University of California San Diego, Scripps Institution of Oceanography, United States, (4)US Army Corps of Engineers, Coastal and Hydraulics Laboratory, Vicksburg, United States, (5)US Army Engineer Research and Development Center, Coastal & Hydraulics Laboratory, Vicksburg, United States
In light of sea level rise, accurately predicting nearshore waves is increasingly important for informing management strategies that require adapting to a changing climate, with the most impactful waves originating from high intensity storms. The active hurricane seasons of 2016-2019 resulted in several devastating landfall hurricanes whose coastal wave climate was captured by an array of directional wave gauges deployed on the entire eastern seaboard. These named storms include Hurricanes Matthew (2016), Irma, Jose, and Maria (2017), Florence (2018), and Dorian (2019). The array provides a unique capability to assess the skill of operational forecasts. Here we focus on NOAA’s operational WaveWatch 3 forecasts, and extend a performance analysis beyond significant height to include properties of the directional wave field and highest individual wave statistics on a per storm basis. For purposes of understanding impacts of model-data mismatch to shoreline erosion prediction, the time-cumulative alongshore component of stress applied by the waves (Sxy) is assessed as that is the principal forcing in the prediction of alongshore sediment transport. This analysis highlights the need for persistent in-situ observations as model errors are too large to predict the annual Sxy budget.

The data used in this assessment is provided by the Coastal Data Information Program (CDIP), an operational wave monitoring and prediction program based at Scripps Institution of Oceanography, University of California, San Diego. CDIP maintains an array of Datawell™ Waverider directional wave buoys in US and territorial waters, with primary funding provided by the US Army Corps of Engineers. In recent years, collaborations with NOAA’s (IOOS) program, including UNC’s Coastal Ocean Research and Monitoring Program (CORMP), have expanded the CDIP array to include over 20 active buoy stations deployed along the U.S. East Coast from Puerto Rico to New England.