National, operational forecasts of shoreline total water levels: A coordinated Federal response to users' questions about coastal change and inundation hazards

“Offshore waves are forecast to be 2 m, but what does that mean for our coastal town – our houses, roads, parking lots, businesses?” This simple question, asked by a mayor in a small coastal town in New Hampshire, pointed to a big gap in information weather forecasters could provide to the public on possible coastal hazards. They were able to give details about tides, winds, and offshore waves, but what that forcing looked like at shoreline and, thus, what coastal residents, emergency managers, local businesses, and vacationers could expect to deal with in the upcoming days were unknown. In order to provide local decision makers with guidance about total shoreline water levels, including tide, surge, and wave runup, and the expected coastal response, the US Geological Survey (USGS) collaborated with the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction and NOAA regional Weather Forecasting Offices (WFOs) to produce hourly, 6-day forecasts of local water levels and the potential for coastal erosion, overwash, and inundation. In this presentation, we will share the story, including frustrating challenges and exciting successes, of how coastal residents with questions about flooding, existing relationships between scientists at three Federal agencies, an extensive collection of coastal elevation data, and some really good timing led to the development of a National operational model for forecasting shoreline water levels and coastal change hazards.