Wind, being one of the forces which commonly tends to increase the risk of capsizing a ship, is well represented in GHS. The overturning moment due to wind can be obtained for a given wind speed or pressure, using a geometric model of the vessel's superstructure and other features subject to wind drag.
Alternatively, if an independently-derived heeling moment is available, this can be entered either as an arbitrary curve or as a sinusoidal function or a straight line.