Wave height in the North Atlantic has been observed to increase over the last quarter-century, based on monthly-mean data derived from observations. Empirical models have linked a large part of this increase in wave height with the North Atlantic Oscillation. Wave models provide a tool to study impacts of various climate change scenarios and investigate physical explanations of statistical results. In this case we use a wave model of the NE Atlantic. Model tests were carried out, using synthetic wind fields, varying the strength of the prevailing westerly winds and the frequency and intensity of storms, the location of storm tracks and the storm propagation speed. The strength of the westerly winds is most effective at increasing mean and maximum monthly wave height. The frequency, intensity, track and speed of storms have little effect on the mean wave height but intensity, track and speed significantly affect maximum wave height.