Forecasting Coastal Impacts from Tropical Cyclones along the US East and Gulf Coasts using the ADCIRC Prediction System

PI: Luettich, Rick (UNC Chapel Hill)
Co-PI(s): Bilskie, Matt (University of Georgia), Blanton, Brian (RENCI, UNC Chapel Hill), Cobell, Zach (The Water Institute of the Gulf), Cox, Dan (Oregon State University), Dietrich, Casey (North Carolina State University), Fleming, Jason (Seahorse Coastal Consulting), Ginis, Isaac, (University of Rhode Island), van de Westhuysen, Andre (NOAA/NWS/NCEP), Abdolali, Ali NOAA/NWS/NCEP
Start Year: 2021 | Duration: 3 years
Partners: University of Georgia, RENCI, UNC Chapel Hill, The Water Institute of the Gulf, Oregon State University, North Carolina State University, Seahorse Coastal Consulting, University of Rhode Island, NOAA/NWS/NCEP

Project Abstract:

The proposed project will develop, deploy and critically evaluate a forecasting system that is
capable of predicting wave, surge, sediment transport, and damage assessment, down to human
scales, due to tropical cyclones impacting the US East and Gulf of Mexico coasts. The proposed
forecasting system will leverage and greatly expand the capabilities of the existing ADCIRC
Prediction System (APS) which is comprised of (i) the coupled ADCIRC+SWAN computational
core; (ii) a national – regional system of unstructured computational meshes that contain
information on bathymetry, topography, land cover and sub-grid scale features; (iii) interfaces to
multiple meteorological models for forcing; (iv) the ADCIRC Surge Guidance System to manage
/ execute the forecast process, including execution of ensembles; (v) extensive experience
performing event based forecasting for tropical cyclones impacting the US East and Gulf of
Mexico coasts. APS forecasts (often several hundred for each storm including ensemble
members) have been generated for every significant tropical cyclone that has threatened the US
East and Gulf of Mexico coasts during the past decade.

For the proposed project, the APS will be enhanced to include updated computational meshes
including new bathymetry, topography and land cover data provided by team members engaged
in task 1 of the proposed NOPP project; ingest of the Navy’s COAMPS-TC tropical cyclone
meteorological model as forcing; evaluation of the newly available ADCIRC+WaveWatchIII
computational core; inclusion of enhanced wave-surge physics; and assimilation of coastal water
levels. APS output will be coupled to a suite of 1D and 2D XBeach simulations to evaluate
morphology change and sediment transport at differing levels of detail as a storm approaches
land. Water level and wave output directly from APS and from the APS+XBeach simulations
will then be used for damage assessment from aggregated to local scales.

Year 1 efforts will focus on modifications to the APS software, e.g., ingest of COAMPS-TC,
initial ADCIRC+WWIII evaluation, wave-surge physics enhancements, mesh updates, setting up
XBeach at a national scale and evaluating the system for hindcast events and/or reanalysis of
forecast events. Model updates and evaluation will continue in Years 2-4 primarily outside of
hurricane season, whereas during hurricane season we will produce daily forecasts of coastal
impacts beginning five days prior to predicted landfall for at least three named storms per year.

BAA: N00014-20-S-B001