Forecasts and Warnings
Forecasting Storm Surge and Coastal Inundation
Forecasters at the National Weather Service (NWS) and the National Hurricane Center (NHC) use a variety of tools in predicting storm surge and coastal inundation. These tools include water level observations, weather forecasts of the storm, satellite data, and storm surge models. The particular tools used depend on what type of event is expected.
The Role of a Forecaster
Forecasts and warnings must be issued for a wide variety of threats to public safety and property, including forecasts of storm surge and coastal inundation. Advances in technology have had a substantial impact on forecasting – improved observational capabilities and the development of new models have significantly improved accuracy.
Forecasters use multiple computer programs and analysis techniques to analyze the latest weather data and computer model forecasts. From this data, a forecaster uses training, prior experience, and his or her expert judgment to create forecasts for an area. For storm surge predictions, NWS experts take the lead in analyzing the storm and its surge-producing potential. Local forecasters then follow the guidance of these experts and create regional forecasts that describe the specific, local impacts of an event. These forecasters work around the country in local weather forecast offices.
Storm surge forecasting begins when NWS experts assess the probability of a storm striking land, and then use storm surge model output and water level observations to assess the potential threat. They forward the results of their analyses to emergency managers, media, and the public using various forecast products. A local weather forecast office will add additional local specific conditions.
One of the main tools forecasters use to predict storm surge is the output from computational models. NOAA's Sea, Lake and Overland Surges from Hurricanes (SLOSH) model aids in the prediction of tropical cyclone storm surge. Forecasters access large libraries of hypothetical storm simulations, create predictions based upon the specific weather forecasts, and assess hundreds of permutations of storms for forecast uncertainties. For extratropical storms, larger scale storm surge models assess potential water levels. Additionally, forecasters also evaluate wave predictions, as they can significantly contribute to storm damage.
Once forecasters have evaluated data from observations, model outputs, and other sources, they write the forecast. Forecasters also provide expert guidance to decision makers, emergency responders, and the media.