Deep Water Wave Generation by Moving Wind Systems

This paper concerns the mathematical justification of a procedure for forecasting wave heights and periods within traveling fetches of variable wind over deep water. The method applies to a fixed wind direction along which both the fetch and the wind magnitude are considered to be variable with time. It adapts observational data on significant heights and periods of waves generated by winds of constant velocity to the general case in which the velocity has a dependency on distance. The graphical procedure devised to handle this situation was originally verified only for stationary fetches of variable wind but is now validated for the general case of the moving fetch. The graphical integrations are here replaced by step-wise numerical integrations, readily performed on a high speed digital computer. A direct comparison made between a machine-run wave hindcast and an earlier graphical one for the occasion of the August, 1915 hurricane, that assailed Galveston, Texas, shows good correspondence.