Wailua/Horners Swell Statistics, July: All Swell – Any Wind
The figure illustrates the range of swells directed at Wailua/Horners over a normal July. It is based on 1984 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the best grid node based on what we know about Wailua/Horners. In the case of Wailua/Horners, the best grid node is 35 km away (22 miles).
The rose diagram shows the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but lacks direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These were forecast only 84% 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 frequently that size swell was forecast.
The diagram suggests that the most common swell direction, shown by the longest spokes, was NNE, 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 Wailua/Horners and away from the coast. We combine these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at Wailua/Horners, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical July, swells large enough to cause surfable waves at Wailua/Horners run for about 16% 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.