NOAA Advancements in Modeling, Observing, and Communicating Storm Surge Hazards

Storm surges are a severe threat to the safety and resiliency of many coastal areas, as shown by recent storms such as Sandy and Isaac. Public safety depends on clear understanding and accurate communication of storm surge risks. This presentation discusses how the National Oceanic and Atmospheric Administration (NOAA) is advancing the prediction and communication of storm surge hazards for both tropical and extratropical storms. These advancements require a wide range of NOAA experts and are being coordinated across the National Ocean Service (NOS), National Weather Service (NWS), and Office of Oceanic and Atmospheric Research (OAR). The NOAA-wide strategy on the advancement of storm surge services is called the Storm Surge Roadmap. It brings together meteorologists, oceanographers, geographers, social scientists, and other experts to advance NOAA's storm surge capabilities. The vision for the Storm Surge Roadmap is to clearly communicate highly accurate, relevant, and timely information, resulting in reductions in loss of life and resilient communities.

NOS and NWS are working together to improve communication of storm surge hazards. NOS social science experts have helped NWS assess understanding of surge risk and gather input from the public, emergency managers, and the media on how to improve communication. This has highlighted confusion about storm surge reference datums and where the flooding will go; surge is now described as inundation above ground level rather than height above an unfamiliar reference datum. This is now reflected in NOS and NWS storm surge products. NOS collects water level observations, including the underlying spatial reference system needed to determine how high flooding will reach. The National Water Level Observation Network (NWLON) gathers storm water levels and includes hardened gauges that accurately captured data. Storm QuickLook provides a synopsis of near real-time oceanographic and meteorological observations at locations affected by a tropical cyclone using reference datums and language consistent with NWS products.

Finally, NOS and NWS are working together to improve storm surge forecasts. Storm surge flooding is caused by the total water level during an event, which is a result of surge, tides, river inflows, and wave conditions. NWS' surge predictions have historically lacked information about astronomical tide conditions, preventing the accurate calculation of the total water level above ground. NOS is providing tide models to upgrade surge predictions to support new NWS surge forecast products, including an inundation map for tropical and extratropical storms. NOS is providing storm surge prediction systems that include the combined effect of surge and tide for extratropical storms on the Atlantic and Pacific coasts. These systems are input to NWS nearshore wave predictions. NOS is also testing higher resolution storm surge predictions for tropical cyclones that include surge and tide effects, and developing an ensemble prediction system based on this approach.