Ala Moana Bowls Swell Statistics, Spring: All Swell – Any Wind
The rose diagram illustrates the range of swells directed at Ala Moana Bowls through an average northern hemisphere spring and is based upon 6580 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the optimum 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 swell direction, while the graph at the bottom shows the same thing without direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These occurred only 65% of the time. Green and yellow show increasing swell sizes and red illustrates largest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the most common swell direction, shown by the longest spokes, was S, whereas the the most common wind blows from the ENE. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Ala Moana Bowls and offshore. We lump these in with the no surf category of the bar chart. To keep it simple we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at Ala Moana Bowls, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical northern hemisphere spring, swells large enough to cause surfable waves at Ala Moana Bowls run for about 35% 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.