Anaehoomalu Bay_A-Bay Swell Statistics, Autumn: All Swell – Any Wind
This picture shows the combination of swells directed at Anaehoomalu Bay_A-Bay over a normal northern hemisphere autumn and is based upon 7252 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coastline so we have chosen the optimum grid node based on what we know about Anaehoomalu Bay_A-Bay. In the case of Anaehoomalu Bay_A-Bay, the best grid node is 15 km away (9 miles).
The rose diagram describes the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but 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 were forecast only 60% of the time. Green and yellow represent increasing swell sizes and red shows the biggest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell happens.
The diagram suggests that the dominant swell direction, shown by the biggest spokes, was NW, whereas the the prevailing wind blows from the NNE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Anaehoomalu Bay_A-Bay 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 graph. Because wind determines whether or not waves are clean enough to surf at Anaehoomalu Bay_A-Bay, you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical northern hemisphere autumn, swells large enough to cause surfable waves at Anaehoomalu Bay_A-Bay run for about 13% 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.