Tidal Improvements to the SLOSH Model

To support transition of coastal inundation modeling research to operations, the National Weather Service's (NWS) Meteorological Development Laboratory (MDL) is enhancing tidal water level calculation to storm surge models for operational modeling.

The Sea Lake and Overland Surges from Hurricanes (SLOSH) model, developed by NWS/MDL, is used for climatological, deterministic and probabilistic prediction of storm surge induced by landfalling hurricanes. The SLOSH model uses a parametric wind model based on forecast track, radius of maximum winds, and differential pressure between ambient and center of storm. MDL's SLOSH model is currently the operational standard used by the National Hurricane Center for storm surge and coastal inundation forecasting. SLOSH sets the bar for operational criteria in terms of accuracy and computational effort.

To improve operational coastal inundation modeling, National Oceanic and Atmospheric Administration's (NOAA) storm surge roadmap identified adding tides to the SLOSH model as a critical short-term requirement. This will provide a more accurate total water level forecast and thereby better predict inundation. Advancements to inundation forecasts will improve our emergency response and support decision making. Providing the results of adding tides to SLOSH will also benefit the research community as they will have a better estimate of the bar they need to meet. This paper will explore various methods of calculating tides in the SLOSH model and limitations of each method.