Development and Validation of Operational Storm Surge Model Guidance

National Ocean Service’s Coast Survey Development Laboratory at the U.S. National Oceanic and Atmospheric Administration (NOAA) is using the ADvanced CIRCulation (ADCIRC) hydrodynamic model to provide operational guidance for storm surges and tides at the US coastlines. ADCIRC solves the fully non-linear shallow water equations, and is capable of providing total water simulations including storm surge, tides, waves and rivers, in a coupled modeling framework. Extratropical Surge and Tide Operational Forecasting System (ESTOFS) was developed to provide a continuous guidance throughout the year. Since 2012, ESTOFS has been deployed for the Pacific and later Atlantic coastlines of the continental US, including Hawaii and Puerto Rico; Micronesia domain including West Pacific US territories is currently in development and testing. For the tropical Atlantic cyclones, Hurricane Surge On-Demand Forecasting System (HSOFS) has been developed to provide ensemble guidance and inland flooding estimates on a higher resolution numerical grid.

Various model skill assessment techniques are used to validate systems’ accuracy against data from the NOAA network of coastal water level observations as well as post-event surveys of peak flood levels (high-water marks). On the example of the 2012 superstorm Sandy hindcast, skill is shown as a measure of improvement and sensitivity to bias correction methods and regional updates of the HSOFS model grid (bathymetry, coastline and land elevation).