Mahai'ula Bay Surf Stats

This image shows the variation of swells directed at Mahai'ula Bay through an average May. It is based on 3414 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind or surf right at the coastline so we have chosen the most applicable grid node based on what we know about Mahai'ula Bay. In the case of Mahai'ula Bay, the best grid node is 24 km away (15 miles). The rose diagram describes the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing without direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These happened only 93% of the time. Green and yellow represent increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how often that size swell happens. The diagram indicates that the prevailing swell direction, shown by the longest spokes, was W, whereas the the prevailing wind blows from the N. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Mahai'ula Bay and out to sea. We combine these with the no surf category of the bar chart. To simplify things we don't show these in the rose graph. Because wind determines whether or not waves are good for surfing at Mahai'ula Bay, you can view an alternative image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical May, swells large enough to cause clean enough to surf waves at Mahai'ula Bay run for about 1.0% of the time.

read more