Developed by the National Weather Service, the SLOSH model estimates storm surge heights resulting from historical, hypothetical, or predicted hurricanes by taking into account the atmospheric pressure, size, forward speed, and track data. These parameters are used to create a model of the wind field which drives the storm surge. The model consists of a set of equations derived from the Newtonian equations of motion (shallow water equations) and the continuity equation applied to a rotating fluid with a free surface.

SLOSH has been applied to the entire U.S. East Coast and Gulf of Mexico coastlines. In addition, coverage extends to Hawaii, Guam, Puerto Rico, and the U.S. Virgin Islands.

The SLOSH model is computationally efficient, resulting in fast computer runs, which makes it an ideal operational system. It is able to resolve flow through barriers, gaps, and passes and models deep passes between bodies of water. It also resolves inland inundation and the overtopping of barrier systems, levees, and roads. It can resolve coastal reflections of surges, such as coastally trapped Kelvin waves. SLOSH also can explicitly model the astronomic tide, as well as provide different initial water level anomalies. However, the SLOSH model does not explicitly model the impacts of waves on top of the surge, nor does it account for normal river flow or rain flooding. Future advancements in the SLOSH model will allow for the resolution of some of these limitations.

The SLOSH model and the SLOSH Display Program (SDP) are two different tools. The SLOSH model is used by the National Hurricane Center to forecast storm surge and model storm surge vulnerability; the SDP is the software provided to emergency managers and other users to visualize the data produced by the National Hurricane Cennter.