Ala Moana Bowls Swell Statistics, May: All Swell – Any Wind
This chart illustrates the variation of swells directed at Ala Moana Bowls over a normal May. It is based on 2200 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast surf and wind right at the coastline so we have chosen the best grid node based on what we know about Ala Moana Bowls, and at Ala Moana Bowls the best grid node is 35 km away (22 miles).
The rose diagram describes the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but without direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These occurred only 37% of the time. Green and yellow represent increasing swell sizes and largest swells greater than >3m (>10ft) are shown in red. In both graphs, the area of any colour is proportional to how commonly that size swell occurs.
The diagram implies that the most common swell direction, shown by the largest spokes, was S, whereas the the most common wind blows from the ENE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Ala Moana Bowls and away from the coast. We group these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose graph. Because wind determines whether or not waves are surfable at Ala Moana Bowls, you can view an alternative image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical May, swells large enough to cause good for surfing waves at Ala Moana Bowls run for about 63% of the time.
IMPORTANT: Beta version feature! Swell heights are open water values from NWW3. There is no attempt to model near-shore effects. Coastal wave heights will generally be less, especially if the break does not have unobstructed exposure to the open ocean.