A representation of a hurricane, with specified characteristics, that is assumed to occur in a particular study area, following a specified path and timing sequence. Transposed--A hypohurricane based on the storm transposition principle, assumed to have wind patterns and other characteristics basically comparable to a specified hurricane of record, but transposed to follow a new path to serve as a basis for computing a hurricane surge hydrograph that would be expected at a selected point. Moderate adjustments in timing or rate of forward movement may also be made, if these are compatible with meteorological considerations and study objectives. Hypohurricane Based on Generalized Parameters--Hypohurricane estimates based on various logical combinations of hurricane characteristics used in estimating hurricane surge magnitudes corresponding to a range of probabilities and potentialities. The Standard Project Hurricane is most commonly used for this purpose, but estimates corresponding to more severe or less severe assumptions are important in some project investigations. Standard Project Hurricane (SPH)--A hypothetical hurricane intended to represent the most severe combination of hurricane parameters that is reasonably characteristic of a specified region, excluding extremely rare combinations. It is further assumed that the SPH would approach a given project site from such direction, and at such rate of movement, to produce the highest Hurricane Surge Hydrograph, considering pertinent hydraulic characteristics of the area. Based on this concept, and on extensive mete orological studies and probability analyses, a tabulation of "Standard Project Hurricane Characteristics" mutually agreed upon by representatives of the U. S. Weather Service and the Corps of Engineers, is available. Probable Maximum Hurricane--A hypohurricane that might result from the most severe combination of hurricane parameters that is considered reasonably possible in the region involved, if the hurricane should approach the point under study along a critical path and at optimum rate of movement. This estimate is substantially more severe than the SPH criteria. Design Hurricane--A representation of a hurricane with specified characteristics that would produce Hurricane Surge Hydrographs and coincident wave effects at various key locations along a proposed project alinement. It governs the project design after economics and other factors have been duly considered. The design hurricane may be more or less severe than the SPH, depending on economics, risk, and local considerations