OBJECTIVE METHODS FOR FORECASTING SEA WAVESThere are a number of different methods for forecasting sea waves. Some of the methods are too technical or time consuming to be of practical use of Aerographer’s Mates.A relationship between wave velocity (c), wave length (L), and period (T) maybe indicated using the equation C = 3.03 T.The length in feet of a deep-water wave (L) may be computed using the equation L = 5.12 T. The period of a wave in seconds (T) may be calculated using the equation T = 0.33 C, where (C) is the wave velocity.Sea state forecasts are divided into four categories: significant wave height (HID), average wave height (HAvG), one-tenth average wave height (HIJ1o), and high wave (Hw).
For more information, refer to the practical training publication Sea and Swell Forecasting, NAVEDTRA 40560, published by the Naval Oceanographic Office. This publication presents a method for forecasting sea waves, and a brief summary follows.In order to prepare an accurate sea state forecast one must frost determine wind speed over the fetch (U), length of the fetch (F), and the length of time the wind speed (u) has remained unchanged within the fetch (u). These parameters are determined using current and/or previous surface charts. Using these parameters and the tables in NAVEDTRA 40560, an accurate sea state forecast may be obtained.
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